Commit Graph

180843 Commits

Author SHA1 Message Date
Stefan Richter
c8a94ded57 firewire: normalize STATE_CLEAR/SET CSR access interface
Push the maintenance of STATE_CLEAR/SET.abdicate down into the card
driver.  This way, the read/write_csr_reg driver method works uniformly
across all CSR offsets.

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
2010-06-19 13:01:41 +02:00
Stefan Richter
db3c9cc105 firewire: replace get_features card driver hook
by feature variables in the fw_card struct.  The hook appeared to be an
unnecessary abstraction in the card driver interface.

Cleaner would be to pass those feature flags as arguments to
fw_card_initialize() or fw_card_add(), but the FairnessControl register
is in the SCLK domain and may therefore not be accessible while Link
Power Status is off, i.e. before the card->driver->enable call from
fw_card_add().

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
2010-06-19 13:01:41 +02:00
Stefan Richter
e847cc832b firewire: drop sizeof expressions from some request size arguments
In case of fw_card_bm_work()'s lock request, the present sizeof
expression is going to be wrong if somebody changes the fw_card's DMA
scratch buffer's size in the future.

In case of quadlet write requests, sizeof(u32) is just silly; it's 4.

In case of SBP-2 ORB pointer write requests, 8 is arguably quicker to
understand as the correct and only possible value than
sizeof(some_datum).

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
2010-06-19 13:01:40 +02:00
Stefan Richter
65b2742ac0 firewire: 'add CSR_... support' addendum
Add a comment on which of the conflicting NODE_IDS specifications we
implement.  Reduce a comment on rather irrelevant register bits that can
all be looked up in the spec (or from now on in the code history).
Directly include the required indirectly included bug.h.

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
2010-06-19 13:01:40 +02:00
Clemens Ladisch
c374ab4242 firewire: core: always enable cycle master packets
As part of the bus manager responsibilities, make sure that the cycle
master sends cycle start packets.  This is needed when the old bus
manager disabled the cycle master's cmstr bit and there are iso-capable
nodes on the new bus.

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
2010-06-10 08:41:51 +02:00
Clemens Ladisch
e91b2787d0 firewire: allocate broadcast channel in hardware
On OHCI 1.1 controllers, let the hardware allocate the broadcast channel
automatically.  This removes a theoretical race condition directly after
a bus reset where it could be possible to read the channel allocation
register with channel 31 still being unallocated.

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
2010-06-10 08:40:49 +02:00
Clemens Ladisch
7e0e314f19 firewire: core: add CSR abdicate support
Implement the abdicate bit, which is required for bus manager
capable nodes and tested by the Base 1394 Test Suite.

Finally, something to do at a command reset!  :-)

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
2010-06-10 08:37:15 +02:00
Clemens Ladisch
4ffb7a6a06 firewire: add CSR cmstr support
Implement the cmstr bit, which is required for cycle master capable
nodes and tested for by the Base 1394 Test Suite.

This bit allows the bus master to disable cycle start packets; there are
bus master implementations that actually do this.

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
2010-06-10 08:36:37 +02:00
Clemens Ladisch
3d1f46eb60 firewire: core: add CSR MAINT_UTILITY support
Implement the MAIN_UTILITY register, which is utterly optional
but useful as a safe target for diagnostic read/write/broadcast
transactions.

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
2010-06-10 08:35:37 +02:00
Clemens Ladisch
a1a1132bd8 firewire: add CSR PRIORITY_BUDGET support
If supported by the OHCI controller, implement the PRIORITY_BUDGET
register, which is required for nodes that can use asynchronous
priority arbitration.

To allow the core to determine what features the lowlevel device
supports, add a new card driver callback.

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
2010-06-10 08:35:06 +02:00
Clemens Ladisch
27a2329f82 firewire: add CSR BUSY_TIMEOUT support
Implement the BUSY_TIMEOUT register, which is required for nodes that
support retries.

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
2010-06-10 08:34:13 +02:00
Clemens Ladisch
a48777e03a firewire: add CSR BUS_TIME support
Implement the BUS_TIME register, which is required for cycle master
capable nodes and tested for by the Base 1393 Test Suite.  Even when
there is not yet bus master initialization support, this register allows
us to work together with other bus masters.

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
2010-06-10 08:33:07 +02:00
Clemens Ladisch
9ab5071cd4 firewire: add CSR CYCLE_TIME write support
The specification requires that CYCLE_TIME is writable so that it can be
initialized, so we better implement it.

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
2010-06-10 08:26:48 +02:00
Clemens Ladisch
8e4b50f94e firewire: core: add CSR SPLIT_TIMEOUT support
Implement the SPLIT_TIMEOUT registers.  Besides being required by the
spec, this is desirable for some IIDC devices and necessary for many
audio devices to be able to increase the timeout from userspace.

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
2010-06-10 08:26:28 +02:00
Clemens Ladisch
446eba0d68 firewire: core: add CSR RESET_START support
This implements the RESET_START register (as a dummy) to make the Base
1394 Test Suite happy.

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
2010-06-10 08:25:46 +02:00
Clemens Ladisch
506f1a3193 firewire: add CSR NODE_IDS support
The NODE_IDS register, and especially its bus_id field, is quite
useless because 1394.1 requires that the bus_id field always stays
0x3ff.  However, the 1394 specification requires this register on all
transaction capable nodes, and the Base 1394 Test Suite tests for it,
so we better implement it.

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
2010-06-10 08:25:19 +02:00
Clemens Ladisch
60d32970c5 firewire: add read_csr_reg driver callback
To prepare for the following additions of more OHCI-implemented CSR
registers, replace the get_cycle_time driver callback with a generic
CSR register callback.

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
2010-06-10 08:24:35 +02:00
Clemens Ladisch
3e07ec0eee firewire: core: add CSR STATE_CLEAR/STATE_SET support
The state registers are zero and read-only in this implementation, so
they are not of much use.  However, the specification requires that they
are present for transaction capable nodes, and the Base 1394 Test Suite
tests for them, so we better implement them.

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
2010-06-10 08:24:03 +02:00
Clemens Ladisch
bda3b8a1fa firewire: core: retry on local errors in bus manager election
When the candidate bus manager fails to do the lock request with which
it tries to become bus manager, it assumes that the current IRM is not
actually IRM capable and forces itself to become root.  However, if that
lock request failed because the local node itself was not able to send
it, then we cannot blame the current IRM and should not steal its
rootness.

In this case, RCODE_SEND_ERROR is likely to indicate a temporary error
condition such as exhausted tlabels or low memory, so we better try
again later.

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
2010-06-10 08:23:28 +02:00
Clemens Ladisch
153e397920 firewire: ohci: speed up PHY register accesses
Most PHY chips, when idle, can complete a register access in the time
needed for two or three PCI read transactions; bigger delays occur only
when data is currently being moved over the link/PHY interface.  So if
we busy-wait a few times when waiting for the register access to finish,
it is likely that we can finish without having to sleep.

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
2010-06-10 08:22:07 +02:00
Stefan Richter
f9c70f9129 firewire: core: trivial fix for warning strings
WARN's format string argument should not carry a printk level prefix.

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
2010-06-09 19:42:18 +02:00
Clemens Ladisch
a10c0ce760 firewire: check cdev response length
Add a check that the data length in the SEND_RESPONSE ioctl is correct.
Incidentally, this also fixes the previously wrong response length of
software-handled lock requests.

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
2010-06-09 19:42:18 +02:00
Clemens Ladisch
262444eecc firewire: ohci: add MSI support
This patch adds support for message-signaled interrupts.

Any native PCI-Express OHCI controller should support MSI, but most are
just PCI cores behind a PCI-E/PCI bridge.  The only chips that are known
to claim to support MSI are the Lucent/Agere/LSI FW643 and the VIA
VT6315, none of which I have been able to test.

Due to the high level of trust I have in the competence of these and any
future chip makers, I thought it a good idea to add a disable-MSI quirk.

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>

Tested Agere FW643 rev 07 [11c1:5901] and JMicron JMB381 [197b:2380].
Added a quirks list entry for JMB38X since it kept its count of MSI
events consistently at zero.

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
2010-06-09 19:42:18 +02:00
Stefan Richter
148c7866c3 firewire: ohci: do not enable interrupts without the handler
On 26 Apr 2010, Clemens Ladisch wrote:
> In theory, none of the interrupts should occur before the link is
> enabled.  In practice, I'd rather make sure to not set the master
> interrupt enable bit until we have installed the interrupt handler.

and proposed to move OHCI1394_masterIntEnable out of the present
reg_write() into a new one before the HCControl.linkEnable reg_write().

Why not defer setting /all/ of the bits until right before linkEnable?

Reviewed-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
2010-06-09 19:42:18 +02:00
Julia Lawall
d8c1fa4af0 ieee1394: video1394: Use memdup_user
...when user data is immediately copied into the allocated region.

Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de> (changelog)
2010-05-31 18:49:52 +02:00
Stefan Richter
3014420b6b ieee1394: schedule for removal
All application domains that are supported by the old ieee1394 driver
stack are supported by the newer firewire driver stack too.  There is
now good and extensive experience with the newer stack from deployment
in Fedora since F7 as well as by enthusiast users of other
distributions.

The new drivers have consequently been recommended as the default ones
since 2.6.33, in order to fix some severe usability problems of FireWire
on Linux due to limitations of the old stack.  It is now high time to
announce when the obsolete drivers will be removed.

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Acked-by: Jarod Wilson <jarod@redhat.com>
2010-05-25 21:37:40 +02:00
Clemens Ladisch
5c40cbfefa firewire: core: use separate timeout for each transaction
Using a single timeout for all transaction that need to be flushed does
not work if the submission of new transactions can defer the timeout
indefinitely into the future.  We need to have timeouts that do not
change due to other transactions; the simplest way to do this is with a
separate timer for each transaction.

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de> (+ one lockdep annotation)
2010-05-19 00:26:30 +02:00
Peter Hurley
753a8970f6 firewire: core: Fix tlabel exhaustion problem
fw_core_handle_response() was not properly clearing tlabel_mask. This
was resulting in premature tlabel exhaustion.

Signed-off-by: Peter Hurley <phurley@charter.net>

This fixes an omission in 2.6.31-rc1 commit 1e626fdc "firewire: core:
use more outbound tlabels" which prevented to really use 64 instead of
32 transaction labels, as soon as split transactions occurred that had
their AR-resp tasklet run after the AT-req tasklet.

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
2010-05-19 00:06:47 +02:00
Clemens Ladisch
7906054f0d firewire: core: make transaction label allocation more robust
If one request is so long-lived that it does not get a response before
the following 63 requests, its bit in tlabel_mask is still set when the
next request tries to allocate a transaction label for that number.  In
this state, while the first request is not completed or timed out, no
new requests can be submitted.

To fix this, skip over any label still in use, and do not error out
unless we have entirely run out of labels.

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
2010-04-19 20:00:44 +02:00
Stefan Richter
edd5bdaf12 firewire: core: clean up config ROM related defined constants
Clemens Ladisch pointed out that
  - BIB_IMC is not named like the field is called in the standard,
  - readers of the code may get worried about the magic 0x0c0083c0,
  - a CSR_NODE_CAPABILITIES key is there in the header but not put to
    good use.

So let's rename BIB_IMC, add a defined constant for Node_Capabilities
and a comment which reassures people that somebody thought about it and
they don't have to (or if they still do, tell them where they have to
look for confirmation), and prune our incomplete and arbitrary set of
defined constants of CSR key IDs.  And there is a nother magic number,
that of Bus_Information_Block.Bus_Name, to be defined and commented.

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
2010-04-19 20:00:44 +02:00
Stefan Richter
7cfe21aae1 ieee1394: mark char device files as not seekable
The
  - raw1394   (/dev/raw1394),
  - video1394 (/dev/video1394/*),
  - dv1394    (/dev/dv1394/*)
character device file ABIs do not make any use of lseek(), pread(), or
pwrite().  Therefore use nonseekable_open() and, redundantly, set
file_operations.llseek to no_llseek to remove any doubt whether the BKL-
grabbing default_llseek handler is used.

Although all this is legacy code which should be left in peace until it
is eventually removed (as it is superseded by firewire-core's
<linux/firewire-cdev.h> ABI), this change seems still worth doing to
further minimize the presence of BKL usage in the kernel.

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
2010-04-10 16:51:15 +02:00
Stefan Richter
3ac26b2ee3 firewire: cdev: mark char device files as not seekable
The <linux/firewire-cdev.h> character device file ABI (i.e. /dev/fw*
character device file interface) does not make any use of lseek(),
pread(), pwrite() (or any kind of write() at all).

Use nonseekable_open() and, redundantly, set file_operations.llseek to
no_llseek to remove any doubt whether the BKL-grabbing default_llseek
handler is used.  (Also shuffle file_operations initialization according
to the order of handler definitions.)

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
2010-04-10 16:51:14 +02:00
Stefan Richter
5da3dac8d9 firewire: ohci: cleanups and fix for nonstandard build without debug facility
1) Clean up two function names:  The ohci_ prefix is only used in names
of fw_card_driver hooks.  There were two unnecessary exceptions.

2) Replace empty macros by empty inline functions so that call parameter
type checking is available in #ifndef'd builds.

3) CONFIG_FIREWIRE_OHCI_DEBUG is currently a hidden kconfig variable,
hence is not going to be switched off by anybody.  Still, it can be
switched off but then compilation will fail in ohci_enable() at the
expression param_debug & OHCI_PARAM_DEBUG_BUSRESETS.  Add the necessary
definitions in the nonstandard case.

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
2010-04-10 16:51:14 +02:00
Stefan Richter
35d999b120 firewire: ohci: wait for PHY register accesses to complete
Rather than having the arbitrary msleep(2) pause, let read_phy_reg()
loop until the link--phy access was finished.

Factor write_phy_reg() out of ohci_update_phy_reg() and of
read_paged_phy_reg() and let it loop too until the link--phy access was
finished.

Like in the older ohci1394 driver, a timeout of 100 milliseconds is
chosen.  Unlike the old driver, we sleep instead of busy-wait in each
waiting loop iteration.  Instead of a loop, the waiting could probably
also be implemented interrupt driven, but why bother.  It would require
up and running interrupt handling before the link was fully configured
and enabled.

Also modify functions a bit:  Error return and value return can be
combined in read_phy_reg() since the domain of values is only u8.
Likewise in read_paged_phy_reg().

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
2010-04-10 16:51:14 +02:00
Clemens Ladisch
54672386cc firewire: ohci: fix up configuration of TI chips
On TI chips (OHCI-Lynx and later), enable link enhancements features
that TI recommends to be used.  None of these are required for proper
operation, but they are safe and nice to have.

In theory, these bits should have been set by default, but in practice,
some BIOS/EEPROM writers apparently do not read the datasheet, or get
spooked by names like "unfair".

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
2010-04-10 16:51:14 +02:00
Clemens Ladisch
925e7a6504 firewire: ohci: enable 1394a enhancements
The OHCI spec says that, if the programPhyEnable bit is set, the driver
is responsible for configuring the IEEE1394a enhancements within the PHY
and the link consistently.  So do this.

Also add a quirk to allow disabling these enhancements; this is needed
for the TSB12LV22 where ack accelerations are buggy (erratum b).

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
2010-04-10 16:51:14 +02:00
Clemens Ladisch
e7014dada0 firewire: ohci: do not clear PHY interrupt status inadvertently
The interrupt status bits in PHY register 5 are cleared by writing a one
bit.  To avoid clearing them unadvertently, do not write them back when
they were read as set, but only when they have been explicitly requested
to be set.

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
2010-04-10 16:51:14 +02:00
Clemens Ladisch
4a96b4fcd6 firewire: ohci: add a function for reading PHY registers
Move the register reading code from ohci_update_phy_reg() into
a function which can be used separately.

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
2010-04-10 16:51:14 +02:00
Stefan Richter
ca658b1e29 firewire: cdev: comment fixlet
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
2010-04-10 16:51:13 +02:00
Clemens Ladisch
aa6fec3cde firewire: cdev: iso packet documentation
Add the missing documentation for iso packets.

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
2010-04-10 16:51:13 +02:00
Stefan Richter
9cac00b8f0 firewire: cdev: fix information leak
A userspace client got to see uninitialized stack-allocated memory if it
specified an _IOC_READ type of ioctl and an argument size larger than
expected by firewire-core's ioctl handlers (but not larger than the
core's union ioctl_arg).

Fix this by clearing the requested buffer size to zero, but only at _IOR
ioctls.  This way, there is almost no runtime penalty to legitimate
ioctls.  The only legitimate _IOR is FW_CDEV_IOC_GET_CYCLE_TIMER with 12
or 16 bytes to memset.

[Another way to fix this would be strict checking of argument size (and
possibly direction) vs. command number.  However, we then need a lookup
table, and we need to allow for slight size deviations in case of 32bit
userland on 64bit kernel.]

Reported-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
2010-04-10 16:51:13 +02:00
Clemens Ladisch
385ab5bcd4 firewire: cdev: require quadlet-aligned headers for transmit packets
The definition of struct fw_cdev_iso_packet seems to imply that the
header_length must be quadlet-aligned, and in fact, specifying an
unaligned header has never really worked when using multiple packet
structures, because the position of the next control word is computed by
rounding the header_length _down_, so the last one to three bytes of the
header would overlap the next control word.

To avoid this problem, check that the header length is properly aligned.

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
2010-04-10 16:51:13 +02:00
Clemens Ladisch
4ba1d9c0c2 firewire: cdev: disallow receive packets without header
In receive contexts, reject packets with header_length==0.  This would
be an instruction to queue zero packets which would not make sense.

This prevents a division by zero in the OHCI driver.

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
2010-04-10 16:51:13 +02:00
Stefan Richter
fe43d6d9cf firewire: core: align driver match with modalias
The driver match strategy was:
  - Match vendor/model/specifier/version of the unit directory.
  - If that was a miss, match vendor from the root directory and
    model/specifier/version of the unit directory.

This was inconsistent with how the modalias string was constructed
until recently (take vendor/model from root directory and specifier/
version from unit directory).  It was also inconsistent with how it is
done since the parent commit:
  - Use vendor/model/specifier/version of the unit directory if possible,
  - fall back to one or more of vendor/model/specifier/version from the
    root directory depending on which ones are not present at the unit
    directory.

Fix this inconsistency by sharing the ROM scanner function between
modalias printer function and driver match function.

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
2010-03-24 22:01:47 +01:00
Stefan Richter
5ae73518cb firewire: core: fix Model_ID in modalias
The modalias string of devices that represent units on a FireWire node
did not show Module_ID entries within unit directories.  This was
because firewire-core searched only the root directory of the
configuration ROM for a Model_ID entry.

We now search first the root directory, then the unit directory.  IOW
honor a unit directory's Model_ID if present, otherwise fall back to the
root directory's model ID (if present).

Furthermore, apply the same change to Vendor_ID.  This had the same
issue but it was less apparent because most devices provide Vendor_ID
only in the root directory.

And finally, also use this strategy for the remaining two IDs in the
modalias, Specifier_ID and Version.  It does not actually make sense to
look for them elsewhere than in the unit directory because they are
mandatory there.  However, a uniform search order simplifies the
implementation and has no adverse affect in practice.

Side notes:
  - The older counterpart of this, nodemgr.c of ieee1394, looked for
    Vendor_ID first in the root directory, then in the unit directory,
    and for Model_ID only in the unit directory.
  - There is a single mainline driver which requires Vendor_ID and
    Model_ID --- the firedtv driver.  This one worked because FireDTVs
    provide Vendor_ID in the root directory and Model_ID identically in
    root directory and unit directory.
  - Apart from firedtv, there are currently no drivers known to me
    (including userspace drivers) that look at the Vendor_ID or Model_ID
    of the modalias.

Reported-by: Maciej Żenczykowski <zenczykowski@gmail.com>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
2010-03-24 22:01:47 +01:00
Clemens Ladisch
8301b91ba0 firewire: ohci: add cycle timer quirk for the TI TSB12LV22
Among the many entries in the TSB12LV22 errata list (TI literature
number SLLS312) is the following:

  PCI Slave reads of the Cycle Timer register may occasionally get an
  incorrect value.
  Software may be able to validate value by reading the register
  multiple times rapidly and evaluating for a reasonable difference.

Signed-off-by: Clemens Ladisch <clemens@ladisch.de> (untested)
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de> (added #define)
2010-03-17 23:24:42 +01:00
Clemens Ladisch
cf36df6bfb firewire: core: fw_iso_resource_manage: fix error handling
If the bandwidth allocation fails, the error must be returned in
*channel regardless of whether the channel allocation succeeded.
Checking for c >= 0 is not correct if no channel allocation was
requested, in which case this part of the code is reached with
c == -EINVAL.

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
2010-03-15 14:29:44 +01:00
Stefan Richter
6fdb2ee243 firewire: ohci: extend initialization log message
by the number of available isochronous DMA contexts and active quirks
which is occasionally useful information.

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
2010-02-24 20:36:55 +01:00
Stefan Richter
4802f16d51 firewire: ohci: fix IR/IT context mask mixup
This bug was present in firewire-ohci since day one:  The number of
available isochronous receive DMA contexts was mixed up with that of
available isochronous transmit DMA contexts.

This is harmless on a few chips which offer the same number of contexts
in both directions, but most chips nowadays implement only the standard
minimum of 4 IR contexts, but 8 IT contexts.  If a user attempted to run
a lot of IR contexts at once, results with more than four were therefore
unpredictable.  I suppose the controller would simply refuse to start
DMA of any unimplemented context.

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
2010-02-24 20:36:55 +01:00
Stefan Richter
3e9cc2f3b7 firewire: ohci: add module parameter to activate quirk fixes
This way, we can advise users of precompiled kernel packages to test
existing quirk fixes on chips which have not been listed yet, without
them having to build a kernel from source.

Note, to use this feature on a machine with more than one controller,
steps like these are necessary:
# lspci | grep 1394
# ls /sys/bus/pci/drivers/firewire_ohci/
# echo -n "0000:03:02.0" > /sys/bus/pci/drivers/firewire_ohci/unbind
# echo 2 > /sys/module/firewire_ohci/parameters/quirks
# echo -n "0000:03:02.0" > /sys/bus/pci/drivers/firewire_ohci/bind
# echo 0 > /sys/module/firewire_ohci/parameters/quirks

The parameter can also be used to switch off quirk flags that were
hardwired into firewire-ohci's quirks table.  Simply specify a non-zero
quirks value but without any known flags, e.g. 0x100.

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
2010-02-24 20:36:55 +01:00