Commit Graph

132 Commits

Author SHA1 Message Date
Thomas Gleixner
d48071be6c can: c_can: Use proper u32 variables in c_can_write_msg_object()
Instead of obfuscating the code by artificial 16 bit splits use the
proper 32 bit assignments and split the result when writing to the
interface.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Alexander Stein <alexander.stein@systec-electronic.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-04-24 22:09:01 +02:00
Thomas Gleixner
23ef0a895d can: c_can: Cleanup c_can_write_msg_object()
Remove the MASK from the TX transfer side.

Make the code readable and get rid of the annoying IFX_WRITE_XXX_16BIT
macros which are just obfuscating the code.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Alexander Stein <alexander.stein@systec-electronic.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-04-24 22:09:01 +02:00
Thomas Gleixner
7af28630b8 can: c_can: Cleanup c_can_msg_obj_put/get()
Sigh!

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Alexander Stein <alexander.stein@systec-electronic.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-04-24 22:09:00 +02:00
Thomas Gleixner
b07faaaf1f can: c_can: Cleanup c_can_inval_msg_object()
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Alexander Stein <alexander.stein@systec-electronic.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-04-24 22:09:00 +02:00
Thomas Gleixner
8ff2de0fb4 can: c_can: Cleanup setup of receive buffers
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Alexander Stein <alexander.stein@systec-electronic.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-04-24 22:09:00 +02:00
Thomas Gleixner
4fb6dccd13 can: c_can: Cleanup c_can_read_msg_object()
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Alexander Stein <alexander.stein@systec-electronic.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-04-24 22:09:00 +02:00
Thomas Gleixner
2d5f4f8569 can: c_can: Cleanup irq enable/disable
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Alexander Stein <alexander.stein@systec-electronic.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-04-24 22:09:00 +02:00
Thomas Gleixner
d61d09de02 can: c_can: Work around C_CAN RX wreckage
Alexander reported that the new optimized handling of the RX fifo
causes random packet loss on Intel PCH C_CAN hardware.

After a few fruitless debugging sessions I got hold of a PCH (eg20t)
afflicted system. That machine does not have the CAN interface wired
up, but it was possible to reproduce the issue with the HW loopback
mode.

As Alexander observed correctly, clearing the NewDat flag along with
reading out the message buffer causes that issue on C_CAN, while D_CAN
handles that correctly.

Instead of restoring the original message buffer handling horror the
following workaround solves the issue:

    transfer buffer to IF without clearing the NewDat
    handle the message
    clear NewDat bit

That's similar to the original code but conditional for C_CAN.

I really wonder why all user manuals (C_CAN, Intel PCH and some more)
recommend to clear the NewDat bit right away. The knows it all Oracle
operated by Gurgle does not unearth any useful information either. I
simply cannot believe that we are the first to uncover that HW issue.

Reported-and-tested-by: Alexander Stein <alexander.stein@systec-electronic.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-04-24 22:09:00 +02:00
Thomas Gleixner
2b9aecdce2 can: c_can: Disable rx split as workaround
The RX buffer split causes packet loss in the hardware:

What happens is:

RX Packet 1 --> message buffer 1 (newdat bit is not cleared)
RX Packet 2 --> message buffer 2 (newdat bit is not cleared)
RX Packet 3 --> message buffer 3 (newdat bit is not cleared)
RX Packet 4 --> message buffer 4 (newdat bit is not cleared)
RX Packet 5 --> message buffer 5 (newdat bit is not cleared)
RX Packet 6 --> message buffer 6 (newdat bit is not cleared)
RX Packet 7 --> message buffer 7 (newdat bit is not cleared)
RX Packet 8 --> message buffer 8 (newdat bit is not cleared)

Clear newdat bit in message buffer 1
Clear newdat bit in message buffer 2
Clear newdat bit in message buffer 3
Clear newdat bit in message buffer 4
Clear newdat bit in message buffer 5
Clear newdat bit in message buffer 6
Clear newdat bit in message buffer 7
Clear newdat bit in message buffer 8

Now if during that clearing of newdat bits, a new message comes in,
the HW gets confused and drops it.

It does not matter how many of them you clear. I put a delay between
clear of buffer 1 and buffer 2 which was long enough that the message
should have been queued either in buffer 1 or buffer 9. But it did not
show up anywhere. The next message ended up in buffer 1. So the
hardware lost a packet of course without telling it via one of the
error handlers.

That does not happen on all clear newdat bit events. I see one of 10k
packets dropped in the scenario which allows us to reproduce. But the
trace looks always the same.

Not splitting the RX Buffer avoids the packet loss but can cause
reordering. It's hard to trigger, but it CAN happen.

With that mode we use the HW as it was probably designed for. We read
from the buffer 1 upwards and clear the buffer as we get the
message. That's how all microcontrollers use it. So I assume that the
way we handle the buffers was never really tested. According to the
public documentation it should just work :)

Let the user decide which evil is the lesser one.

[ Oliver Hartkopp: Provided a sane config option and help text and
  made me switch to favour potential and unlikely reordering over
  packet loss ]

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Alexander Stein <alexander.stein@systec-electronic.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-04-24 22:09:00 +02:00
Thomas Gleixner
fa39b54ccf can: c_can: Get rid of pointless interrupts
The driver handles pointlessly TWO interrupts per packet. The reason
is that it enables the status interrupt which fires for each rx and tx
packet and it enables the per message object interrupts as well.

The status interrupt merily acks or in case of D_CAN ignores the TX/RX
state and then the message object interrupt fires.

The message objects interrupts are only useful if all message objects
have hardware filters activated.

But we don't have that and its not simple to implement in that driver
without rewriting it completely.

So we can ditch the message object interrupts and handle the RX/TX
right away from the status interrupt. Instead of TWO we handle ONE.

Note: We must keep the TXIE/RXIE bits in the message buffers because
the status interrupt alone is not reliable enough in corner cases.

If we ever have the need for HW filtering, then this code needs a
complete overhaul and we can think about it then. For now we prefer a
lower interrupt load.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Alexander Stein <alexander.stein@systec-electronic.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-04-24 22:08:57 +02:00
Thomas Gleixner
b9011aae93 can: c_can: Avoid status register update for D_CAN
On D_CAN the RXOK, TXOK and LEC bits are cleared/set on read of the
status register. No need to update them.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Alexander Stein <alexander.stein@systec-electronic.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-04-24 22:08:57 +02:00
Thomas Gleixner
6b48ff8d93 can: c_can: Simplify buffer reenabling
Instead of writing to the message object we can simply clear the
NewDat bit with the get method.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Alexander Stein <alexander.stein@systec-electronic.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-04-24 22:08:57 +02:00
Thomas Gleixner
1da394d889 can: c_can: Always update error stats
If the allocation of the error skb fails, we still want to see the
error statistics.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Alexander Stein <alexander.stein@systec-electronic.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-04-24 22:08:57 +02:00
Thomas Gleixner
097aec1968 can: c_can: Fix berr reporting
Reading the LEC type with

  return (mode & ENABLED) && (status & LEC_MASK);

is not guaranteed to return (status & LEC_MASK) if the enabled bit in
mode is set. It's guaranteed to return 0 or !=0.

Remove the inline function and call unconditionally into the
berr_handling code and return early when the reporting is disabled.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Alexander Stein <alexander.stein@systec-electronic.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-04-24 22:08:56 +02:00
Thomas Gleixner
f058d548e8 can: c_can: Handle state change correctly
If the allocation of an error skb fails, the state change handling
returns w/o doing any work. That leaves the interface in a wreckaged
state as the internal status is wrong.

Split the interface handling and the skb handling.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Alexander Stein <alexander.stein@systec-electronic.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-04-24 22:08:56 +02:00
Thomas Gleixner
9c64863a49 can: c_can: Do not access skb after net_receive_skb()
There is no guarantee that the skb is in the same state after calling
net_receive_skb(). It might be freed or reused. Not really harmful as
its a read access, except you turn on the proper debugging options
which catch a use after free.

The whole can subsystem is full of this. Copy and paste ....

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Alexander Stein <alexander.stein@systec-electronic.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-04-24 22:08:56 +02:00
Thomas Gleixner
ef1d2e286a can: c_can: Make bus off interrupt disable logic work
The state change handler is called with device interrupts disabled
already. So no point in disabling them again when we enter bus off
state.

But what's worse is that we reenable the interrupts at the end of NAPI
poll unconditionally. So c_can_start() which is called from the
restart timer can trigger interrupts which confuse the hell out of the
half reinitialized driver/hw.

Remove the pointless device interrupt disable in the BUS_OFF handler
and prevent reenabling the device interrupts at the end of the poll
routine when the current state is BUS_OFF.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Alexander Stein <alexander.stein@systec-electronic.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-04-24 22:08:55 +02:00
Thomas Gleixner
bed11db3d4 can: c_can: Fix startup logic
c_can_start() enables interrupts way too early. The first enabling
happens when setting the control mode in c_can_chip_config() and then
again at the end of the function.

But that happens before napi_enable() and that means that an interrupt
which comes in will disable interrupts again and call napi_schedule,
which ignores the request and the later napi_enable() is not making
thinks work either. So the interface is up with all device interrupts
disabled.

Move the device interrupt after napi_enable() and add it to the other
callsites of c_can_start() in c_can_set_mode() and c_can_power_up()

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Alexander Stein <alexander.stein@systec-electronic.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-04-24 22:08:55 +02:00
Thomas Gleixner
129eef2184 can: c_can_pci: Set the type of the IP core
All type checks in c_can.c are != BOSCH_D_CAN so nobody noticed so far
that the pci code does not update the type information.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Alexander Stein <alexander.stein@systec-electronic.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-04-24 22:08:55 +02:00
David S. Miller
f91ca783f1 linux-can-fixes-for-3.15-20140401
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Merge tag 'linux-can-fixes-for-3.15-20140401' of git://gitorious.org/linux-can/linux-can

linux-can-fixes-for-3.15-20140401

Marc Kleine-Budde says:

====================
this is a pull request of 16 patches for the 3.15 release cycle.

Bjorn Van Tilt contributes a patch which fixes a memory leak in usb_8dev's
usb_8dev_start_xmit()s error path. A patch by Robert Schwebel fixes a typo in
the can documentation. The remaining patches all target the c_can driver. Two
of them are by me; they add a missing netif_napi_del() and return value
checking. Thomas Gleixner contributes 12 patches, which address several
shortcomings in the driver like hardware initialisation, concurrency, message
ordering and poor performance.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2014-04-01 17:49:50 -04:00
Thomas Gleixner
b1d8e431bd can: c_can: Avoid led toggling for every packet.
There is no point to toggle the RX led for every packet. Especially if
we have a full FIFO we want to avoid everything we can.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-04-01 11:55:02 +02:00
Thomas Gleixner
5a7513adab can: c_can: Simplify TX interrupt cleanup
The function loads the message object from the hardware to get the
payload length. The previous patch stores that information in an
array, so we can avoid the hardware access.

Remove the hardware access and move the led toggle outside of the
spinlocked region. Toggle the led only once when at least one packet
has been received.

Binary size shrinks along with the code

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-04-01 11:55:01 +02:00
Thomas Gleixner
9024700854 can: c_can: Store dlc private
We can avoid the HW access in TX cleanup path for retrieving the DLC
of the sent package if we store the DLC in a private array.

Ideally this should be handled in the can_echo_skb functions, but I
leave that exercise to the CAN folks.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-04-01 11:55:01 +02:00
Thomas Gleixner
c0a9f4d396 can: c_can: Reduce register access
commit 4ce78a838c (can: c_can: Speed up rx_poll function) hyped a
performance improvement by reducing the access to the interrupt
pending register from a dual 16 bit to a single 16 bit access. Wow!

Thereby it crippled the driver to cast the 16 msg objects in stone,
which is completly braindead as contemporary hardware has up to 128
message objects. Supporting larger object buffers is a major surgery,
but it'd be definitely worth it especially as the driver does not
support HW message filtering ....

The logic of the "FIFO" implementation is to split the FIFO in half.

For the lower half we read the buffers and clear the interrupt pending
bit, but keep the newdat bit set, so the HW will queue above those
buffers.

When we read out the last low buffer then we reenable all the low half
buffers by clearing the newdat bit.

The upper half buffers clear the newdat and the interrupt pending bit
right away as we know that the lower half bits are clear and give us a
headstart against the hardware.

Now the implementation is:

    transfer_message_object()
    read_object_and_put_into_skb();

    if (obj < END_OF_LOW_BUF)
       clear_intpending(obj)
    else if (obj > END_OF_LOW_BUF)
       clear_intpending_and_newdat(obj)
    else if (obj == END_OF_LOW_BUF)
       clear_newdat_of_all_low_objects()

The hardware allows to avoid most of the mess simply because we can
tell the transfer_message_object() function to clear bits right away.

So we can be clever and do:

   if (obj <= END_OF_LOW_BUF)
      ctrl = TRANSFER_MSG | CLEAR_INTPND;
   else
      ctrl = TRANSFER_MSG | CLEAR_INTPND | CLEAR_NEWDAT;

    transfer_message_object(ctrl)
    read_object_and_put_into_skb();

    if (obj == END_OF_LOW_BUF)
       clear_newdat_of_all_low_objects()

So we save a complete control operation on all message objects except
the one which is the end of the low buffer. That's a few micro seconds
per object.

I'm not adding a boasting profile to that, simply because it's self
explaining.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
[mkl: adjusted subject and commit message]
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-04-01 11:55:01 +02:00
Thomas Gleixner
520f570c43 can: c_can: Make the code readable
If every other line contains line breaks, that's a clear sign for
indentation level madness. Split out the inner loop and move the code
to a separate function. gcc creates slightly worse code for that, but
we'll fix that in the next step.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
[mkl: adjusted subject]
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-04-01 11:55:00 +02:00
Thomas Gleixner
bf88a20611 can: c_can: Provide protection in the xmit path
The network core does not serialize the access to the hardware. The
xmit related code lets the following happen:

CPU0 	     	       CPU1
interrupt()
 do_poll()
   c_can_do_tx()
    Fiddle with HW and	xmit()
    internal data	  Fiddle with HW and
    	     		  internal data

due the complete lack of serialization.

Add proper locking.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-04-01 11:55:00 +02:00
Thomas Gleixner
710c56105d can: c_can: Remove EOB exit
The rx_poll code has the following gem:

	if (msg_ctrl_save & IF_MCONT_EOB)
		return num_rx_pkts;

The EOB bit is the indicator for the hardware that this is the last
configured FIFO object. But this object can contain valid data, if we
manage to free up objects before the overrun case hits.

Now if the code exits due to the EOB bit set, then this buffer is
stale and the interrupt bit and NewDat bit of the buffer are still
set. Results in a nice interrupt storm unless we come into an overrun
situation where the MSGLST bit gets set.

     ksoftirqd/0-3     [000] ..s.    79.124101: c_can_poll: rx_poll: val: 00008001 pend 00008001
     ksoftirqd/0-3     [000] ..s.    79.124176: c_can_poll: rx_poll: val: 00008000 pend 00008000
     ksoftirqd/0-3     [000] ..s.    79.124187: c_can_poll: rx_poll: val: 00008002 pend 00008002
     ksoftirqd/0-3     [000] ..s.    79.124256: c_can_poll: rx_poll: val: 00008000 pend 00008000
     ksoftirqd/0-3     [000] ..s.    79.124267: c_can_poll: rx_poll: val: 00008000 pend 00008000

The amazing thing is that the check of the MSGLST (aka overrun bit)
used to be after the check of the EOB bit. That was "fixed" in commit
5d0f801a2c(can: c_can: Fix RX message handling, handle lost message
before EOB). But the author of this "fix" did not even understand that
the EOB check is broken as well.

Again a simple solution: Remove

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
[mkl: adjusted subject and commit message]
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-04-01 11:54:59 +02:00
Thomas Gleixner
07c7b6f616 can: c_can: Fix the lost message handling
The lost message handling is broken in several ways.

1) Clearing the message lost flag is done by writing 0 to the
   message control register of the object.

   #define IF_MCONT_CLR_MSGLST    (0 << 14)

   That clears the object buffer configuration in the worst case,
   which results in a loss of the EOB flag. That leaves the FIFO chain
   without a limit and causes a complete lockup of the HW

2) In case that the error skb allocation fails, the code happily
   claims that it handed down a packet. Just an accounting bug, but ....

3) The code adds a lot of pointless overhead to that error case, where
   we need to get stuff done as fast as possible to avoid more packet
   loss.

   - printk an annoying error message
   - reread the object buffer for nothing

Fix is simple again:

  - Use the already known MSGCTRL content and only clear the MSGLST bit
  - Fix the buffer accounting by adding a proper return code
  - Remove the pointless operations

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-04-01 11:54:59 +02:00
Thomas Gleixner
64f08f2f35 can: c_can: Fix buffer ordering
The buffer handling of c_can has been broken forever. That leads to
message reordering:

ksoftirqd/0-3     [000] ..s.    79.123776: c_can_poll: rx_poll: val: 00007fff
ksoftirqd/0-3     [000] ..s.    79.124101: c_can_poll: rx_poll: val: 00008001

What happens is:

CPU				HW
				queue new packet into obj 16 (0-15 are busy)
read obj 1-15
return because pending is 0
				set pending obj 16 -> pending reg 8000
				queue new packet into obj 1
				set pending obj 1 -> pending reg 8001

So the current algorithmus reads the newest message first, which
violates the ordering rules of CAN.

Add proper handling of that situation by analyzing the contents of the
pending register for gaps.

This does NOT fix the message object corruption which can lead to
interrupt storms. Thats addressed in the next patches.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
[mkl: adjusted subject]
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-04-01 11:54:58 +02:00
Thomas Gleixner
640916db2b can: c_can: Make it SMP safe
The hardware has two message control interfaces, but the code only uses the
first one. So on SMP the following can be observed:

CPU0 	       	CPU1
rx_poll()
  write IF1	xmit()
		write IF1
  write IF1

That results in corrupted message object configurations. The TX/RX is not
globally serialized it's only serialized on a core.

Simple solution: Let RX use IF1 and TX use IF2 and all is good.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-04-01 11:54:58 +02:00
Thomas Gleixner
5bb9cbaa62 can: c_can: Fix hardware raminit function
The function is broken in several ways:

    - The function does not wait for the init to complete.
      That can take quite some microseconds.

    - No protection against being called for two chips at the same
      time. SMP is such a new thing, right?

Clear the start and the init done bit unconditionally and wait for both bits to
be clear.

In the enable path set the init bit and wait for the init done bit.

Add proper locking.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-04-01 11:54:57 +02:00
Thomas Gleixner
9fac1d1ab8 can: c_can: Wait for CONTROL_INIT to be cleared
According to the documentation the CPU must wait for CONTROL_INIT to
be cleared before writing to the baudrate registers.

Signed-off-by: Benedikt Spranger <b.spranger@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-04-01 11:54:57 +02:00
Marc Kleine-Budde
130a5171da can: c_can: check return value to users of c_can_set_bittiming()
This patch adds return value checking to all direct and indirect users of
c_can_set_bittiming().

Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-04-01 11:54:56 +02:00
Marc Kleine-Budde
f29b423834 can: c_can: free_c_can_dev(): add missing netif_napi_del()
This patch adds the missing netif_napi_del() to the free_c_can_dev() function.

Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-04-01 11:54:56 +02:00
Oliver Hartkopp
c971fa2ae4 can: Unify MTU settings for CAN interfaces
CAN interfaces only support MTU values of 16 (CAN 2.0) and 72 (CAN FD).
Setting the MTU to other values is pointless but it does not really hurt.
With the introduction of the CAN FD support in drivers/net/can a new
function to switch the MTU for CAN FD has been introduced.

This patch makes use of this can_change_mtu() function to check for correct
MTU settings also in legacy CAN (2.0) devices.

Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-03-17 09:20:16 +01:00
Markus Pargmann
4ce78a838c can: c_can: Speed up rx_poll function
This patch speeds up the rx_poll function by reducing the number of
register reads.

Replace the 32bit register read by a 16bit register read. Currently
the 32bit register read is implemented by using 2 16bit reads. This is
inefficient as we only use the lower 16bit in rx_poll.

The for loop reads the pending interrupts in every iteration. This
leads up to 16 reads of pending interrupts. The patch introduces a new
outer loop to read the pending interrupts as long as 'quota' is above 0.
This reduces the total number of reads.

The third change is to replace the for-loop by a ffs loop.

Tested on AM335x. I removed all 'static' and 'inline' from c_can.c to
see the timings for all functions. I used the function tracer with
trace_stats.

125kbit:
  Function                               Hit    Time            Avg             s^2
  --------                               ---    ----            ---             ---
  c_can_do_rx_poll                     63960    10168178 us     158.977 us      1493056 us
With patch:
  c_can_do_rx_poll                     63941    3764057 us      58.867 us       776162.2 us

1Mbit:
  Function                               Hit    Time            Avg             s^2
  --------                               ---    ----            ---             ---
  c_can_do_rx_poll                     69489    30049498 us     432.435 us      9271851 us
With patch:
  c_can_do_rx_poll                    207109    24322185 us     117.436 us      171469047 us

Signed-off-by: Markus Pargmann <mpa@pengutronix.de>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2013-12-17 11:47:19 +01:00
Holger Bechtold
7ee330c7b3 can: c_can: fix calculation of transmitted bytes on tx complete
The number of bytes transmitted was not updated correctly, if several CAN
messages (with different length) were transmitted in one 'bunch'. Thus
programs like 'ifconfig' showed wrong transmit byte counts. Reason was, that
the message object whose DLC is to be read was not necessarily the active one
at the time when

    priv->read_reg(priv, C_CAN_IFACE(MSGCTRL_REG, 0)) & IF_MCONT_DLC_MASK;

was executed.

Signed-off-by: Holger Bechtold <Holger.Bechtold@gmx.net>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2013-11-25 21:48:54 +01:00
Marc Kleine-Budde
e35d46adc4 can: c_can: don't call pm_runtime_get_sync() from interrupt context
The c_can driver contians a callpath (c_can_poll -> c_can_state_change ->
c_can_get_berr_counter) which may call pm_runtime_get_sync() from the IRQ
handler, which is not allowed and results in "BUG: scheduling while atomic".

This problem is fixed by introducing __c_can_get_berr_counter, which will not
call pm_runtime_get_sync().

Reported-by: Andrew Glen <AGlen@bepmarine.com>
Tested-by: Andrew Glen <AGlen@bepmarine.com>
Signed-off-by: Andrew Glen <AGlen@bepmarine.com>
Cc: linux-stable <stable@vger.kernel.org>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2013-11-25 21:48:51 +01:00
David S. Miller
394efd19d5 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Conflicts:
	drivers/net/ethernet/emulex/benet/be.h
	drivers/net/netconsole.c
	net/bridge/br_private.h

Three mostly trivial conflicts.

The net/bridge/br_private.h conflict was a function signature (argument
addition) change overlapping with the extern removals from Joe Perches.

In drivers/net/netconsole.c we had one change adjusting a printk message
whilst another changed "printk(KERN_INFO" into "pr_info(".

Lastly, the emulex change was a new inline function addition overlapping
with Joe Perches's extern removals.

Signed-off-by: David S. Miller <davem@davemloft.net>
2013-11-04 13:48:30 -05:00
Markus Pargmann
5d0f801a2c can: c_can: Fix RX message handling, handle lost message before EOB
If we handle end of block messages with higher priority than a lost message,
we can run into an endless interrupt loop.

This is reproducable with a am335x processor and "cansequence -r" at 1Mbit.
As soon as we loose a packet we can't escape from an interrupt loop.

This patch fixes the problem by handling lost packets before EOB packets.

Cc: linux-stable <stable@vger.kernel.org>
Signed-off-by: Markus Pargmann <mpa@pengutronix.de>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2013-10-31 20:18:47 +01:00
Sachin Kamat
b85f75ea04 net: can: c_can_platform: Remove redundant of_match_ptr
The data structure of_match_ptr() protects is always compiled in.
Hence of_match_ptr() is not needed.

Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Cc: Marc Kleine-Budde <mkl@pengutronix.de>
Cc: linux-can@vger.kernel.org
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-10-01 12:30:25 -04:00
Jingoo Han
5fabc336fe can: c_can: remove unnecessary pci_set_drvdata()
The driver core clears the driver data to NULL after device_release
or on probe failure. Thus, it is not needed to manually clear the
device driver data to NULL.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2013-09-21 15:43:15 +02:00
Chen Gang
6439fbce10 can: c_can: fix error checking of priv->instance in probe()
This patch adds a type cast from 'unsigned int' to 'int'.

'priv->instance' may less than zero, so need a type cast, the related
warnings (allmodconfig, "EXTRA_CFLAGS=-W"):

  drivers/net/can/c_can/c_can_platform.c:198:3: warning: comparison of unsigned expression < 0 is always false [-Wtype-limits]

Signed-off-by: Chen Gang <gang.chen@asianux.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2013-08-22 09:40:19 +02:00
Wolfram Sang
d25903f894 drivers/net/can/c_can: don't use devm_pinctrl_get_select_default() in probe
Since commit ab78029 (drivers/pinctrl: grab default handles from device core),
we can rely on device core for setting the default pins. Compile tested only.

Acked-by: Linus Walleij <linus.walleij@linaro.org> (personally at LCE13)
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Acked-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-07-11 17:18:26 -07:00
Tushar Behera
32766fff24 net: can: Convert to use devm_ioremap_resource
Commit 75096579c3 ("lib: devres: Introduce devm_ioremap_resource()")
introduced devm_ioremap_resource() and deprecated the use of
devm_request_and_ioremap().

Signed-off-by: Tushar Behera <tushar.behera@linaro.org>
CC: netdev@vger.kernel.org
CC: linux-can@vger.kernel.org
CC: Marc Kleine-Budde <mkl@pengutronix.de>
CC: Wolfgang Grandegger <wg@grandegger.com>
Acked-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-06-12 02:22:35 -07:00
Jingoo Han
5e946e5623 net: can: c_can: remove unnecessary platform_set_drvdata()
The driver core clears the driver data to NULL after device_release
or on probe failure, since commit 0998d06310
(device-core: Ensure drvdata = NULL when no driver is bound).
Thus, it is not needed to manually clear the device driver data to NULL.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2013-05-16 13:27:18 +02:00
David S. Miller
188d1f76d0 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Conflicts:
	drivers/net/ethernet/intel/e1000e/ethtool.c
	drivers/net/vmxnet3/vmxnet3_drv.c
	drivers/net/wireless/iwlwifi/dvm/tx.c
	net/ipv6/route.c

The ipv6 route.c conflict is simple, just ignore the 'net' side change
as we fixed the same problem in 'net-next' by eliminating cached
neighbours from ipv6 routes.

The e1000e conflict is an addition of a new statistic in the ethtool
code, trivial.

The vmxnet3 conflict is about one change in 'net' removing a guarding
conditional, whilst in 'net-next' we had a netdev_info() conversion.

The iwlwifi conflict is dealing with a WARN_ON() conversion in
'net-next' vs. a revert happening in 'net'.

Signed-off-by: David S. Miller <davem@davemloft.net>
2013-02-05 14:12:20 -05:00
Alexander Stein
2bd3bc4e84 can: c_can: Set reserved bit in IFx_MASK2 to 1 on write
According to C_CAN documentation, the reserved bit in IFx_MASK2 register is
fixed 1.

Cc: linux-stable <stable@vger.kernel.org>
Signed-off-by: Alexander Stein <alexander.stein@systec-electronic.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2013-02-01 10:20:22 +01:00
David S. Miller
f1e7b73acc Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Bring in the 'net' tree so that we can get some ipv4/ipv6 bug
fixes that some net-next work will build upon.

Signed-off-by: David S. Miller <davem@davemloft.net>
2013-01-29 15:32:13 -05:00
Olivier Sobrie
6ea4588686 can: c_can: fix invalid error codes
Errors in CAN protocol (location) are reported in data[3] of the can
frame instead of data[2].

Cc: linux-stable <stable@vger.kernel.org>
Cc: Bhupesh Sharma <bhupesh.sharma@st.com>
Signed-off-by: Olivier Sobrie <olivier@sobrie.be>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2013-01-26 17:11:24 +01:00
Fabio Baltieri
5090f80560 can: c_can: add LED trigger support
Add support for canbus activity led indicators on c_can devices by
calling appropriate can_led functions.

These are only enabled when CONFIG_CAN_LEDS is Y, becomes no-op
otherwise.

Cc: Bhupesh Sharma <bhupesh.sharma@st.com>
Cc: AnilKumar Ch <anilkumar@ti.com>
Cc: Wolfgang Grandegger <wg@grandegger.com>
Cc: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Fabio Baltieri <fabio.baltieri@gmail.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2013-01-26 16:59:00 +01:00
Marc Kleine-Budde
6586c5d74e can: Kconfig: convert 'depends on CAN_DEV' into 'if CAN_DEV...endif' block
This patch adds an 'if CAN_DEV...endif' Block around the CAN driver
symbols in drivers/net/can/Kconfig. So the 'depends on CAN' dependencies
can be removed.

Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2013-01-26 16:58:58 +01:00
Greg Kroah-Hartman
1dd06ae8db drivers/net: fix up function prototypes after __dev* removals
The __dev* removal patches for the network drivers ended up messing up
the function prototypes for a bunch of drivers.  This patch fixes all of
them back up to be properly aligned.

Bonus is that this almost removes 100 lines of code, always a nice
surprise.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-12-07 14:22:22 -05:00
Bill Pemberton
3c8ac0f2ad can: remove __dev* attributes
CONFIG_HOTPLUG is going away as an option.  As result the __dev*
markings will be going away.

Remove use of __devinit, __devexit_p, __devinitdata, __devinitconst,
and __devexit.

Signed-off-by: Bill Pemberton <wfp5p@virginia.edu>
Cc: Wolfgang Grandegger <wg@grandegger.com>
Cc: Marc Kleine-Budde <mkl@pengutronix.de>
Cc: linux-can@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-12-03 11:16:11 -08:00
Marc Kleine-Budde
69c0c5b15a can: c_can_platform: add MODULE_DEVICE_TABLE
This patch adds a MODULE_DEVICE_TABLE for the of and platform bindings, so that
the module can be loaded automatically by udev.

Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2012-11-27 09:49:34 +01:00
AnilKumar Ch
52cde85acc can: c_can: Add d_can raminit support
Add D_CAN raminit support to C_CAN driver to enable D_CAN RAM,
which holds all the message objects during transmission or
receiving of data. This initialization/de-initialization should
be done in synchronous with D_CAN clock.

In case of AM335X-EVM (current user of D_CAN driver) message RAM is
controlled through control module register for both instances. So
control module register details is required to initialization or
de-initialization of message RAM according to instance number.

Control module memory resource is obtained from D_CAN dt node and
instance number obtained from device tree aliases node.

This patch was tested on AM335x-EVM along with pinctrl data addition
patch, d_can dt aliases addition and control module data addition.
pinctrl data addition is not added to am335x-evm.dts (only supports
CPLD profile#0) because d_can1 is supported under CPLD profile#1.

Signed-off-by: AnilKumar Ch <anilkumar@ti.com>
[mkl: fix instance for non DT in probe, cleaned up raminit]
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2012-11-27 09:49:31 +01:00
AnilKumar Ch
c523530ce1 can: c_can: fix segfault during rmmod
This patch fixes an oops which occurs during unloading the driver.
unregister_c_can_dev() is doing c_can/d_can module interrupts disable, which
requires module clock enable. c_can/d_can interrupts enable/disable is handled
properly in c_can_start and c_can_stop, so removing from
unregister_c_can_dev().

The problem was triggered by adding runtime PM support to the c_can driver by
this commit:

4cdd34b can: c_can: Add runtime PM support to Bosch C_CAN/D_CAN controller

Signed-off-by: AnilKumar Ch <anilkumar@ti.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2012-09-27 16:34:02 +02:00
AnilKumar Ch
006cd138fc can: c_can: Adopt pinctrl support
Adopt pinctrl support to c_can driver based on c_can device
pointer, pinctrl driver configure SoC pins to d_can mode
according to definitions provided in .dts file.

In device specific device tree file 'pinctrl-names = "default";'
and 'pinctrl-0 = <&d_can1_pins>;' needs to add to configure pins
from c_can driver. d_can1_pins node contains the pinmux/config
details of d_can L/H pins.

Signed-off-by: AnilKumar Ch <anilkumar@ti.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2012-09-21 23:58:48 +02:00
AnilKumar Ch
8212003260 can: c_can: Add d_can suspend resume support
Adds suspend resume support to DCAN driver which enables
DCAN power down mode bit (PDR). Then DCAN will ack the local
power-down mode by setting PDA bit in STATUS register.

Signed-off-by: AnilKumar Ch <anilkumar@ti.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2012-09-21 23:58:47 +02:00
AnilKumar Ch
4cdd34b268 can: c_can: Add runtime PM support to Bosch C_CAN/D_CAN controller
Add Runtime PM support to C_CAN/D_CAN controller. The runtime PM
APIs control clocks for C_CAN/D_CAN IP and prevent access to the
register of C_CAN/D_CAN IP when clock is turned off.

Signed-off-by: AnilKumar Ch <anilkumar@ti.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2012-09-21 23:58:47 +02:00
AnilKumar Ch
2469627d17 can: c_can: Add device tree support to Bosch C_CAN/D_CAN controller
Add device tree support to C_CAN/D_CAN controller and usage details
are added to device tree documentation. Driver was tested on AM335x
EVM.

Signed-off-by: AnilKumar Ch <anilkumar@ti.com>
For the of binding doc:
Reviewed-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2012-09-21 23:58:47 +02:00
AnilKumar Ch
f27b1db95d can: c_can: Modify c_can device names
Modify c_can device names from *_CAN_DEVTYPE to BOSCH_*_CAN to make
use of same names for array indexes in c_can_id_table[] as well as
device names.

This patch also add indexes to c_can_id_table array.

Signed-off-by: AnilKumar Ch <anilkumar@ti.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2012-09-21 23:58:47 +02:00
Viresh Kumar
2b1463ddde net/c_can: remove conditional compilation of clk code
With addition of dummy clk_*() calls for non CONFIG_HAVE_CLK cases in clk.h,
there is no need to have clk code enclosed in #ifdef CONFIG_HAVE_CLK, #endif
macros.

Signed-off-by: Viresh Kumar <viresh.kumar@st.com>
Acked-by: David S. Miller <davem@davemloft.net>
Cc: Bhupesh Sharma <bhupesh.sharma@st.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Mike Turquette <mturquette@linaro.org>
Cc: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Cc: viresh kumar <viresh.linux@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-07-30 17:25:12 -07:00
Marc Kleine-Budde
194b9a4cb9 can: mark bittiming_const pointer in struct can_priv as const
This patch marks the bittiming_const pointer as in the struct can_pric as
"const". This allows us to mark the struct can_bittiming_const in the CAN
drivers as "const", too.

Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2012-07-20 12:31:05 +02:00
Marc Kleine-Budde
1aa2d1daf0 can: c_can_pci: fix compilation on non HAVE_CLK archs
In commit:

  5b92da0 c_can_pci: generic module for C_CAN/D_CAN on PCI

the c_can_pci driver has been added. It uses clk_*() functions
resulting in a link error on archs without clock support. This
patch removed these clk_() functions as these parts of the driver
are not tested.

Cc: Federico Vaga <federico.vaga@gmail.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-06-20 13:46:29 -07:00
Federico Vaga
5b92da0443 c_can_pci: generic module for C_CAN/D_CAN on PCI
Signed-off-by: Federico Vaga <federico.vaga@gmail.com>
Acked-by: Giancarlo Asnaghi <giancarlo.asnaghi@st.com>
Cc: Alan Cox <alan@linux.intel.com>
Acked-by: Wolfgang Grandegger <wg@grandegger.com>
Acked-by: Bhupesh Sharma <bhupesh.sharma@st.com>
[mkl: fix call to pci_iounmap]
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2012-06-19 21:22:28 +02:00
David S. Miller
7e52b33bd5 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Conflicts:
	net/ipv6/route.c

This deals with a merge conflict between the net-next addition of the
inetpeer network namespace ops, and Thomas Graf's bug fix in
2a0c451ade which makes sure we don't
register /proc/net/ipv6_route before it is actually safe to do so.

Signed-off-by: David S. Miller <davem@davemloft.net>
2012-06-15 15:51:55 -07:00
Dan Carpenter
d9cb9bd63e can: c_can: precedence error in c_can_chip_config()
(CAN_CTRLMODE_LISTENONLY & CAN_CTRLMODE_LOOPBACK) is (0x02 & 0x01) which
is zero so the condition is never true.  The intent here was to test
that both flags were set.

Cc: <stable@kernel.org> # 2.6.39+
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-06-15 15:25:56 -07:00
AnilKumar Ch
69927fccd9 can: c_can: Add support for Bosch D_CAN controller
This patch adds the support for D_CAN controller driver to the existing
C_CAN driver.

Bosch D_CAN controller is a full-CAN implementation which is compliant
to CAN protocol version 2.0 part A and B. Bosch D_CAN user manual can be
obtained from: http://www.semiconductors.bosch.de/media/en/pdf/
ipmodules_1/can/d_can_users_manual_111.pdf

A new array is added for accessing the d_can registers, according to d_can
controller register space.

Current D_CAN implementation has following limitations, this is done
to avoid large changes to the C_CAN driver.
1. Message objects are limited to 32, 16 for RX and 16 for TX. C_CAN IP
   supports upto 32 message objects but in case of D_CAN we can configure
   upto 128 message objects.
2. Using two 16bit reads/writes for accessing the 32bit D_CAN registers.
3. These patches have been tested on little endian machine, there might
   be some hidden endian-related issues due to the nature of the accesses
   (32-bit registers accessed as 2 16-bit registers). However, I do not
   have a big-endian D_CAN implementation to confirm.

Signed-off-by: AnilKumar Ch <anilkumar@ti.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2012-06-07 10:02:27 +02:00
AnilKumar Ch
33f8100977 can: c_can: Move overlay structure to array with offset as index
c_can uses overlay structure for accessing c_can module registers.
With this kind of implementation it is difficult to add one more ip
which is similar to c_can in functionality but different register
offsets.

This patch changes the overlay structure implementation to an array
with register offset as index. This way we can overcome the above
limitation.

Signed-off-by: AnilKumar Ch <anilkumar@ti.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2012-06-07 10:02:24 +02:00
AnilKumar Ch
f461f27a44 can: c_can: fix race condition in c_can_open()
Fix the issue of C_CAN interrupts getting disabled forever when canconfig
utility is used multiple times. According to NAPI usage we disable all
the hardware interrupts in ISR and re-enable them in poll(). Current
implementation calls napi_enable() after hardware interrupts are enabled.
If we get any interrupts between these two steps then we do not process
those interrupts because napi is not enabled. Mostly these interrupts
come because of STATUS is not 0x7 or ERROR interrupts. If napi_enable()
happens before HW interrupts enabled then c_can_poll() function will be
called eventual re-enabling.

This patch moves the napi_enable() call before interrupts enabled.

Cc: stable@kernel.org # 2.6.39+
Signed-off-by: AnilKumar Ch <anilkumar@ti.com>
Acked-by: Wolfgang Grandegger <wg@grandegger.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2012-06-03 18:59:20 +02:00
AnilKumar Ch
148c87c89e can: c_can: fix an interrupt thrash issue with c_can driver
This patch fixes an interrupt thrash issue with c_can driver.

In c_can_isr() function interrupts are disabled and enabled only in
c_can_poll() function. c_can_isr() & c_can_poll() both read the
irqstatus flag. However, irqstatus is always read as 0 in c_can_poll()
because all C_CAN interrupts are disabled in c_can_isr(). This causes
all interrupts to be re-enabled in c_can_poll() which in turn causes
another interrupt since the event is not really handled. This keeps
happening causing a flood of interrupts.

To fix this, read the irqstatus register in isr and use the same cached
value in the poll function.

Cc: stable@kernel.org # 2.6.39+
Signed-off-by: AnilKumar Ch <anilkumar@ti.com>
Acked-by: Wolfgang Grandegger <wg@grandegger.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2012-06-03 18:59:19 +02:00
AnilKumar Ch
617caccebe can: c_can: fix "BUG! echo_skb is occupied!" during transmit
This patch fixes an issue with transmit routine, which causes
"can_put_echo_skb: BUG! echo_skb is occupied!" message when
using "cansequence -p" on D_CAN controller.

In c_can driver, while transmitting packets tx_echo flag holds
the no of can frames put for transmission into the hardware.

As the comment above c_can_do_tx() indicates, if we find any packet
which is not transmitted then we should stop looking for more.
In the current implementation this is not taken care of causing the
said message.

Also, fix the condition used to find if the packet is transmitted
or not. Current code skips the first tx message object and ends up
checking one extra invalid object.

While at it, fix the comment on top of c_can_do_tx() to use the
terminology "packet" instead of "package" since it is more
standard.

Cc: stable@kernel.org # 2.6.39+
Signed-off-by: AnilKumar Ch <anilkumar@ti.com>
Acked-by: Wolfgang Grandegger <wg@grandegger.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2012-06-03 18:59:18 +02:00
Axel Lin
871d337255 net/can: convert drivers/net/can/* to use module_platform_driver()
This patch converts the drivers in drivers/net/can/* to use the
module_platform_driver() macro which makes the code smaller and a bit
simpler.

Cc: Wolfgang Grandegger <wg@grandegger.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Bhupesh Sharma <bhupesh.sharma@st.com>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Grant Likely <grant.likely@secretlab.ca>
Cc: Anatolij Gustschin <agust@denx.de>
Cc: Paul Bolle <pebolle@tiscali.nl>
Cc: Kurt Van Dijck <kurt.van.dijck@eia.be>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Axel Lin <axel.lin@gmail.com>
Acked-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-11-29 00:25:05 -05:00
Huang Weiyi
4570a5248b can: c_can: remove duplicated #include
Remove duplicated #include('s) in
  drivers/net/can/c_can/c_can.c
  drivers/net/can/c_can/c_can_platform.c

Signed-off-by: Huang Weiyi <weiyi.huang@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-07-23 20:01:15 -07:00
Jesper Juhl
95cb3656c0 net: Remove unneeded version.h includes from drivers/net/
It was pointed out by 'make versioncheck' that some includes of
linux/version.h are not needed in drivers/net/.
This patch removes them.

Signed-off-by: Jesper Juhl <jj@chaosbits.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-06-24 02:40:08 -07:00
Lucas De Marchi
25985edced Fix common misspellings
Fixes generated by 'codespell' and manually reviewed.

Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
2011-03-31 11:26:23 -03:00
Jan Altenberg
dc760b375e can: c_can: Fix tx_bytes accounting
The current SocketCAN implementation for the Bosch c_can cell doesn't
account the TX bytes correctly, because it calls
c_can_inval_msg_object() (which clears the msg ctrl register) before
reading the DLC value:

for (/* nix */; (priv->tx_next - priv->tx_echo) > 0; priv->tx_echo++) {
        msg_obj_no = get_tx_echo_msg_obj(priv);
        c_can_inval_msg_object(dev, 0, msg_obj_no);
        val = c_can_read_reg32(priv, &priv->regs->txrqst1);
        if (!(val & (1 << msg_obj_no))) {
                can_get_echo_skb(dev,
                                msg_obj_no - C_CAN_MSG_OBJ_TX_FIRST);
                stats->tx_bytes += priv->read_reg(priv,
                                &priv->regs->ifregs[0].msg_cntrl)
                                & IF_MCONT_DLC_MASK;
                stats->tx_packets++;
        }
}

So, we will always read 0 for the DLC value and "ifconfig" will report
*0* TX Bytes.

The fix is quite easy: Just move c_can_inval_msg_object() to the end of
the if() statement. So:
      * We only call c_can_inval_msg_object() if the message was
        actually transmitted
      * We read out the DLC value _before_ clearing the msg ctrl
        register

Signed-off-by: Jan Altenberg <jan@linutronix.de>
Acked-by: Kurt Van Dijck <kurt.van.dijck@eia.be>
Acked-by: Wolfgang Grandegger <wg@grandegger.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-03-27 23:35:01 -07:00
Marc Kleine-Budde
b0052b088c can: c_can_platform: fix irq check in probe
This patch fixes the check in the probe function whether a IRQ was supplied
to the driver. The original driver check the irq "struct resource *" against
<= 0. Use "platform_get_irq" instead.

Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Cc: Bhupesh Sharma <bhupesh.sharma@st.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-03-27 23:35:01 -07:00
Marc Kleine-Budde
ee6f0988a6 can: c_can: disable one shot mode until driver is fixed
This patch disables the one shot mode, until the driver has been fixed and
tested to support it.

> I'm quite sure I've seen a situation where msg_obj 17 "seemed" to be
> pending, while msg_obj 18 and 19 already have been transmitted. But
> in that case, I enabled ONESHOT for the can interface, which enables
> the DA mode (automatic retransmission is disabled).

Reported-by: Jan Altenberg <jan@linutronix.de>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Kurt Van Dijck <kurt.van.dijck@eia.be>
Cc: Bhupesh Sharma <bhupesh.sharma@st.com>
Acked-by: Wolfgang Grandegger <wg@grandegger.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-03-27 23:35:00 -07:00
Jan Altenberg
4f2d56c45f can: c_can: Do basic c_can configuration _before_ enabling the interrupts
I ran into some trouble while testing the SocketCAN driver for the BOSCH
C_CAN controller. The interface is not correctly initialized, if I put
some CAN traffic on the line, _while_ the interface is being started
(which means: the interface doesn't come up correcty, if there's some RX
traffic while doing 'ifconfig can0 up').

The current implementation enables the controller interrupts _before_
doing the basic c_can configuration. I think, this should be done the
other way round.

The patch below fixes things for me.

Signed-off-by: Jan Altenberg <jan@linutronix.de>
Acked-by: Kurt Van Dijck <kurt.van.dijck@eia.be>
Acked-by: Wolfgang Grandegger <wg@grandegger.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-03-21 18:19:26 -07:00
Bhupesh Sharma
881ff67ad4 can: c_can: Added support for Bosch C_CAN controller
Bosch C_CAN controller is a full-CAN implementation which is compliant
to CAN protocol version 2.0 part A and B. Bosch C_CAN user manual can be
obtained from:

http://www.semiconductors.bosch.de/media/en/pdf/ipmodules_1/c_can/users_manual_c_can.pdf

This patch adds the support for this controller.
The following are the design choices made while writing the controller
driver:
1. Interface Register set IF1 has be used only in the current design.
2. Out of the 32 Message objects available, 16 are kept aside for RX
   purposes and the rest for TX purposes.
3. NAPI implementation is such that both the TX and RX paths function
   in polling mode.

Signed-off-by: Bhupesh Sharma <bhupesh.sharma@st.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-02-13 22:51:44 -08:00