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Commit Graph

157 Commits

Author SHA1 Message Date
Johan Hovold
348fbd6170 serial: xilinx_uartps: drop low-latency workaround
Commit c8dbdc842d ("serial: xuartps: Rewrite the interrupt handling
logic") reworked the driver interrupt processing but also, without
comment, added an unnecessary workaround for the infamous low_latency
behaviour of tty_flip_buffer_push() which had been removed years
before.

Specifically, since commit a9c3f68f3c ("tty: Fix low_latency BUG"),
tty_flip_buffer_push() always schedules a work item to push data to the
line discipline and there's no need to keep any low_latency hacks around.

Cc: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20210421095509.3024-27-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-22 12:09:26 +02:00
Lee Jones
b482bd793c tty: serial: xilinx_uartps: Supply description for missing member 'cts_override'
Fixes the following W=1 kernel build warning(s):

 drivers/tty/serial/xilinx_uartps.c:205: warning: Function parameter or member 'cts_override' not described in 'cdns_uart'

Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jiri Slaby <jirislaby@kernel.org>
Cc: Michal Simek <michal.simek@xilinx.com>
Cc: linux-serial@vger.kernel.org
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Link: https://lore.kernel.org/r/20201104193549.4026187-23-lee.jones@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-11-06 10:54:05 +01:00
Gustavo A. R. Silva
df561f6688 treewide: Use fallthrough pseudo-keyword
Replace the existing /* fall through */ comments and its variants with
the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary
fall-through markings when it is the case.

[1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through

Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
2020-08-23 17:36:59 -05:00
Helmut Grohne
22a82fa7d6 tty: xilinx_uartps: Really fix id assignment
The problems started with the revert (18cc7ac8a2). The
cdns_uart_console.index is statically assigned -1. When the port is
registered, Linux assigns consecutive numbers to it. It turned out that
when using ttyPS1 as console, the index is not updated as we are reusing
the same cdns_uart_console instance for multiple ports. When registering
ttyPS0, it gets updated from -1 to 0, but when registering ttyPS1, it
already is 0 and not updated.

That led to 2ae11c46d5. It assigns the index prior to registering
the uart_driver once. Unfortunately, that ended up breaking the
situation where the probe order does not match the id order. When using
the same device tree for both uboot and linux, it is important that the
serial0 alias points to the console. So some boards reverse those
aliases. This was reported by Jan Kiszka. The proposed fix was reverting
the index assignment and going back to the previous iteration.

However such a reversed assignement (serial0 -> uart1, serial1 -> uart0)
was already partially broken by the revert (18cc7ac8a2). While the
ttyPS device works, the kmsg connection is already broken and kernel
messages go missing. Reverting the id assignment does not fix this.

>From the xilinx_uartps driver pov (after reverting the refactoring
commits), there can be only one console. This manifests in static
variables console_pprt and cdns_uart_console. These variables are not
properly linked and can go out of sync. The cdns_uart_console.index is
important for uart_add_one_port. We call that function for each port -
one of which hopefully is the console. If it isn't, the CON_ENABLED flag
is not set and console_port is cleared. The next cdns_uart_probe call
then tries to register the next port using that same cdns_uart_console.

It is important that console_port and cdns_uart_console (and its index
in particular) stay in sync. The index assignment implemented by
Shubhrajyoti Datta is correct in principle. It just may have to happen a
second time if the first cdns_uart_probe call didn't encounter the
console device. And we shouldn't change the index once the console uart
is registered.

Reported-by: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com>
Reported-by: Jan Kiszka <jan.kiszka@web.de>
Link: https://lore.kernel.org/linux-serial/f4092727-d8f5-5f91-2c9f-76643aace993@siemens.com/
Fixes: 18cc7ac8a2 ("Revert "serial: uartps: Register own uart console and driver structures"")
Fixes: 2ae11c46d5 ("tty: xilinx_uartps: Fix missing id assignment to the console")
Fixes: 76ed2e1057 ("Revert "tty: xilinx_uartps: Fix missing id assignment to the console"")
Signed-off-by: Helmut Grohne <helmut.grohne@intenta.de>
Cc: stable <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20200713073227.GA3805@laureti-dev
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-07-21 18:12:03 +02:00
Jan Kiszka
76ed2e1057 Revert "tty: xilinx_uartps: Fix missing id assignment to the console"
This reverts commit 2ae11c46d5.

It turned out to break the ultra96-rev1, e.g., which uses uart1 as
serial0 (and stdout-path = "serial0:115200n8").

Fixes: 2ae11c46d5 ("tty: xilinx_uartps: Fix missing id assignment to the console")
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Reviewed-by: Michal Simek <michal.simek@xilinx.com>
Tested-by: Michal Simek <michal.simek@xilinx.com>
Link: https://lore.kernel.org/r/f4092727-d8f5-5f91-2c9f-76643aace993@siemens.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-06-27 16:16:37 +02:00
Greg Kroah-Hartman
1cc18584e5 Merge 5.7-rc5 into tty-next
We need the tty fixes in here too.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-11 08:55:10 +02:00
Shubhrajyoti Datta
2ae11c46d5 tty: xilinx_uartps: Fix missing id assignment to the console
When serial console has been assigned to ttyPS1 (which is serial1 alias)
console index is not updated property and pointing to index -1 (statically
initialized) which ends up in situation where nothing has been printed on
the port.

The commit 18cc7ac8a2 ("Revert "serial: uartps: Register own uart console
and driver structures"") didn't contain this line which was removed by
accident.

Fixes: 18cc7ac8a2 ("Revert "serial: uartps: Register own uart console and driver structures"")
Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Link: https://lore.kernel.org/r/ed3111533ef5bd342ee5ec504812240b870f0853.1588602446.git.michal.simek@xilinx.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-04 18:55:45 +02:00
Greg Kroah-Hartman
e947861d0c Merge 5.7-rc3 into tty-next
We need the tty/serial fixes in here too.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-27 09:33:21 +02:00
Raviteja Narayanam
a8e7346b7c serial: uartps: Use cdns_uart_tx_empty in console_write
Instead of accessing the registers and checking for tx_empty,
use cdns_uart_tx_empty in cdns_uart_console_write function.

Signed-off-by: Raviteja Narayanam <raviteja.narayanam@xilinx.com>
Reviewed-by: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com>
Link: https://lore.kernel.org/r/1586413563-29125-3-git-send-email-raviteja.narayanam@xilinx.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-16 16:15:14 +02:00
Raviteja Narayanam
42e11948dd serial: uartps: Wait for tx_empty in console setup
On some platforms, the log is corrupted while console is being
registered. It is observed that when set_termios is called, there
are still some bytes in the FIFO to be transmitted.

So, wait for tx_empty inside cdns_uart_console_setup before calling
set_termios.

Signed-off-by: Raviteja Narayanam <raviteja.narayanam@xilinx.com>
Reviewed-by: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com>
Link: https://lore.kernel.org/r/1586413563-29125-2-git-send-email-raviteja.narayanam@xilinx.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-16 16:15:14 +02:00
Michal Simek
18cc7ac8a2 Revert "serial: uartps: Register own uart console and driver structures"
This reverts commit 024ca329bf.

As Johan says, this driver needs a lot more work and these changes are
only going in the wrong direction:
  https://lkml.kernel.org/r/20190523091839.GC568@localhost

Reported-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Cc: stable <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/1ee35667e36a8efddee381df5fe495ad65f4d15c.1585905873.git.michal.simek@xilinx.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-16 16:00:48 +02:00
Michal Simek
492cc08bc1 Revert "serial: uartps: Move Port ID to device data structure"
This reverts commit bed25ac0e2.

As Johan says, this driver needs a lot more work and these changes are
only going in the wrong direction:
  https://lkml.kernel.org/r/20190523091839.GC568@localhost

Reported-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Cc: stable <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/eb0ec98fecdca9b79c1a3ac0c30c668b6973b193.1585905873.git.michal.simek@xilinx.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-16 16:00:48 +02:00
Michal Simek
72d6819728 Revert "serial: uartps: Change uart ID port allocation"
This reverts commit ae1cca3fa3.

With setting up NR_PORTS to 16 to be able to use serial2 and higher
aliases and don't loose functionality which was intended by these changes.

As Johan says, this driver needs a lot more work and these changes are
only going in the wrong direction:
  https://lkml.kernel.org/r/20190523091839.GC568@localhost

Reported-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Cc: stable <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/a94931b65ce0089f76fb1fe6b446a08731bff754.1585905873.git.michal.simek@xilinx.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-16 16:00:48 +02:00
Michal Simek
91c9dfa25c Revert "serial: uartps: Do not allow use aliases >= MAX_UART_INSTANCES"
This reverts commit 2088cfd882.

As Johan says, this driver needs a lot more work and these changes are
only going in the wrong direction:
  https://lkml.kernel.org/r/20190523091839.GC568@localhost

Reported-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Cc: stable <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/dac3898e3e32d963f357fb436ac9a7ac3cbcf933.1585905873.git.michal.simek@xilinx.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-16 16:00:48 +02:00
Michal Simek
b6fd2dbbd6 Revert "serial: uartps: Fix error path when alloc failed"
This reverts commit 32cf21ac4e.

As Johan says, this driver needs a lot more work and these changes are
only going in the wrong direction:
  https://lkml.kernel.org/r/20190523091839.GC568@localhost

Reported-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Cc: stable <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/46cd7f039db847c08baa6508edd7854f7c8ff80f.1585905873.git.michal.simek@xilinx.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-16 16:00:48 +02:00
Michal Simek
8da1a3940d Revert "serial: uartps: Use the same dynamic major number for all ports"
This reverts commit ab26266601.

As Johan says, this driver needs a lot more work and these changes are
only going in the wrong direction:
  https://lkml.kernel.org/r/20190523091839.GC568@localhost

Reported-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Cc: stable <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/14a565fc1e14a5ec6cc6a6710deb878ae8305f22.1585905873.git.michal.simek@xilinx.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-16 16:00:48 +02:00
Michal Simek
2e01911b7c Revert "serial: uartps: Fix uartps_major handling"
This reverts commit 5e9bd2d70a.

As Johan says, this driver needs a lot more work and these changes are
only going in the wrong direction:
    https://lkml.kernel.org/r/20190523091839.GC568@localhost

Reported-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Cc: stable <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/310999ab5342f788a7bc1b0e68294d4f052cad07.1585905873.git.michal.simek@xilinx.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-16 16:00:48 +02:00
Raviteja Narayanam
706bbc572d serial: uartps: Add TACTIVE check in cdns_uart_tx_empty function
Make sure that all bytes are transmitted out of Uart by monitoring
CDNS_UART_SR_TACTIVE bit as well.

Signed-off-by: Raviteja Narayanam <raviteja.narayanam@xilinx.com>
Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com>
Acked-by: Maarten Brock <m.brock@vanmierlo.com>
Link: https://lore.kernel.org/r/e2514818af5973be291cc117d07739f068b71639.1584610774.git.shubhrajyoti.datta@xilinx.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-03-24 12:23:04 +01:00
Raviteja Narayanam
97451855cc serial: uartps: Remove unconditional wait inside set_termios
set_termios function should not wait for the transmit FIFO empty
(CDNS_UART_SR_TXEMPTY) unconditionally. The tty layer takes care
of it based on the parameter passed (TCSANOW/TCSADRAIN/TCSAFLUSH).

Signed-off-by: Raviteja Narayanam <raviteja.narayanam@xilinx.com>
Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com>
Link: https://lore.kernel.org/r/536e190dd5bbb474007a67e6323c048288942a28.1584610774.git.shubhrajyoti.datta@xilinx.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-03-24 12:23:03 +01:00
Maarten Brock
1d3c2ea44b serial: xilinx_uartps: set_mctrl sets RTS and DTR
set_mctrl now sets RTS and DTR.

Signed-off-by: Maarten Brock <m.brock@vanmierlo.com>
Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com>
Link: https://lore.kernel.org/r/1574687731-21563-3-git-send-email-shubhrajyoti.datta@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-01-14 14:34:04 +01:00
Maarten Brock
6d8bf787a6 serial: xilinx_uartps: set_termios sets flowcontrol
Let set_termios enable/disable automatic flow control.
set_mctrl should not touch automatic flow control.

Signed-off-by: Maarten Brock <m.brock@vanmierlo.com>
Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com>
Link: https://lore.kernel.org/r/1574687731-21563-2-git-send-email-shubhrajyoti.datta@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-01-14 14:34:04 +01:00
Maarten Brock
422c6d3b09 serial: xilinx_uartps: Let get_mctrl return status
Some of the applications like microcom do not work if
modem is disabled. To fix them we always return
TIOCM_CTS | TIOCM_DSR | TIOCM_CAR instead of 0 when
using cts_override. Make get_mctrl return actual status
when not using cts_override.

Signed-off-by: Maarten Brock <m.brock@vanmierlo.com>
Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com>
Link: https://lore.kernel.org/r/1574687731-21563-1-git-send-email-shubhrajyoti.datta@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-01-14 14:34:04 +01:00
Dmitry Safonov
ebaa8c6f22 tty/serial: Migrate xilinx_uartps to use has_sysrq
The SUPPORT_SYSRQ ifdeffery is not nice as:
- May create misunderstanding about sizeof(struct uart_port) between
  different objects
- Prevents moving functions from serial_core.h
- Reduces readability (well, it's ifdeffery - it's hard to follow)

In order to remove SUPPORT_SYSRQ, has_sysrq variable has been added.
Initialise it in driver's probe and remove ifdeffery.

Cc: Michal Simek <michal.simek@xilinx.com>
Cc: linux-arm-kernel@lists.infradead.org
Signed-off-by: Dmitry Safonov <dima@arista.com>
Link: https://lore.kernel.org/r/20191213000657.931618-53-dima@arista.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-12-18 15:05:10 +01:00
Michal Simek
5e9bd2d70a serial: uartps: Fix uartps_major handling
There are two parts which should be fixed. The first one is to assigned
uartps_major at the end of probe() to avoid complicated logic when
something fails.
The second part is initialized uartps_major number to 0 when last device is
removed. This will ensure that on next probe driver will ask for new
dynamic major number.

Fixes: ab26266601 ("serial: uartps: Use the same dynamic major number for all ports")
Reported-by: Paul Thomas <pthomas8589@gmail.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Link: https://lore.kernel.org/r/d2652cda992833315c4f96f06953eb547f928918.1570194248.git.michal.simek@xilinx.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-10-04 15:14:20 +02:00
Stephen Rothwell
2bf593f101 xilinx_uartps.c: suppress "may be used uninitialised" warning
A powerpc allyesconfig build produces this warning:

In file included from include/linux/radix-tree.h:16,
                 from include/linux/idr.h:15,
                 from include/linux/kernfs.h:13,
                 from include/linux/sysfs.h:16,
                 from include/linux/kobject.h:20,
                 from include/linux/device.h:16,
                 from include/linux/platform_device.h:13,
                 from drivers/tty/serial/xilinx_uartps.c:16:
drivers/tty/serial/xilinx_uartps.c: In function 'cdns_uart_console_write':
include/linux/spinlock.h:288:3: warning: 'flags' may be used uninitialized in this function [-Wmaybe-uninitialized]
   _raw_spin_unlock_irqrestore(lock, flags); \
   ^~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/tty/serial/xilinx_uartps.c:1197:16: note: 'flags' was declared here
  unsigned long flags;
                ^~~~~

It looks like gcc just can't track the relationship between "locked"
and "flags", and it is obvious that "flags" won't be used when "locked"
is zero, so the simplest thing is to initialise flags.

Cc: Jiri Slaby <jslaby@suse.com>
Cc: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Link: https://lore.kernel.org/r/20190731160557.6a09c3e1@canb.auug.org.au
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-09-04 12:43:49 +02:00
Nava kishore Manne
8d53935d9b serial: uartps: Remove useless return from cdns_uart_poll_put_char
There is no reason to call return at the end of function which should
return void.

The patch is also remove one checkpatch warning:
WARNING: void function return statements are not generally useful
+	return;
+}

Fixes: 6ee04c6c54 ("tty: xuartps: Add polled mode support for xuartps")
Signed-off-by: Nava kishore Manne <nava.manne@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-18 09:34:28 +02:00
Nava kishore Manne
7be7a0145f serial: uartps: Do not add a trailing semicolon to macro
This patch fixes this checkpatch warning:
WARNING: macros should not use a trailing semicolon
+#define to_cdns_uart(_nb) container_of(_nb, struct cdns_uart, \
+		clk_rate_change_nb);

Fixes: d9bb3fb126 ("tty: xuartps: Rebrand driver as Cadence UART")
Signed-off-by: Nava kishore Manne <nava.manne@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-18 09:34:28 +02:00
Nava kishore Manne
a53f82d6cc serial: uartps: Fix long line over 80 chars
Trivial patch which fixes one checkpatch warning:
WARNING: line over 80 characters
+		       !(readl(port->membase + CDNS_UART_SR)
			& CDNS_UART_SR_TXFULL)) {

Fixes: c8dbdc842d ("serial: xuartps: Rewrite the interrupt handling logic")
Signed-off-by: Nava kishore Manne <nava.manne@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-18 09:34:28 +02:00
Nava kishore Manne
b6415f2439 serial: uartps: Fix multiple line dereference
Trivial patch which fixes this checkpatch warning:
WARNING: Avoid multiple line dereference - prefer 'port->state->xmit.tail'
+				port->state->xmit.buf[port->state->xmit.
+				tail], port->membase + CDNS_UART_FIFO);

Fixes: c8dbdc842d ("serial: xuartps: Rewrite the interrupt handling logic")
Signed-off-by: Nava kishore Manne <nava.manne@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-18 09:34:27 +02:00
Nava kishore Manne
26d5a3245b serial: uartps: Use octal permission for module_param()
Octal permission is preffered compare to symbolic one.

This patch fixes checkpatch warnings:
Symbolic permissions 'S_IRUGO' are not preferred. Consider using octal
permissions '0444'.

Fixes: 85baf542d5 ("tty: xuartps: support 64 byte FIFO size")
Signed-off-by: Nava kishore Manne <nava.manne@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-18 09:34:27 +02:00
Shubhrajyoti Datta
ab26266601 serial: uartps: Use the same dynamic major number for all ports
Let kernel to find out major number dynamically for the first device and
then reuse it for other instances.
This fixes the issue that each uart is registered with a
different major number.

After the patch:
crw-------    1 root     root      253,   0 Jun 10 08:31 /dev/ttyPS0
crw--w----    1 root     root      253,   1 Jan  1  1970 /dev/ttyPS1

Fixes: 024ca329bf ("serial: uartps: Register own uart console and driver structures")
Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-18 09:34:27 +02:00
Shubhrajyoti Datta
277375b864 serial: uartps: Add a timeout to the tx empty wait
In case the cable is not connected then the target gets into
an infinite wait for tx empty.
Add a timeout to the tx empty wait.

Reported-by: Jean-Francois Dagenais <jeff.dagenais@gmail.com>
Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-10 19:08:32 +02:00
Shubhrajyoti Datta
107475685a serial: uartps: Move the spinlock after the read of the tx empty
Currently we are doing a read of the status register.
Move the spinlock after that as the reads need not be spinlock
protected. This patch prevents relaxing the cpu with spinlock held.

Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-10 19:08:31 +02:00
Shubhrajyoti Datta
1863178b20 serial: uartps: Add support for cts-override
Having flow is configurable. Add support for the same by
checking for cts-override.

Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-04-29 16:20:24 +02:00
Rajan Vaja
f694936c3b tty: xilinx_uartps: Correct return value in probe
Existing driver checks for alternate clock if devm_clk_get() fails
and returns error code for last clock failure. If xilinx_uartps is
called before clock driver, devm_clk_get() returns -EPROBE_DEFER.
In this case, probe should not check for alternate clock as main
clock is already present in DTS and return -EPROBE_DEFER only.

This patch fixes it by not checking for alternate clock when main
clock get returns -EPROBE_DEFER.

Signed-off-by: Rajan Vaja <rajan.vaja@xilinx.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-03-01 18:07:34 +01:00
Anssi Hannula
7abab16051 serial: uartps: Fix stuck ISR if RX disabled with non-empty FIFO
If RX is disabled while there are still unprocessed bytes in RX FIFO,
cdns_uart_handle_rx() called from interrupt handler will get stuck in
the receive loop as read bytes will not get removed from the RX FIFO
and CDNS_UART_SR_RXEMPTY bit will never get set.

Avoid the stuck handler by checking first if RX is disabled. port->lock
protects against race with RX-disabling functions.

This HW behavior was mentioned by Nathan Rossi in 43e98facc4a3 ("tty:
xuartps: Fix RX hang, and TX corruption in termios call") which fixed a
similar issue in cdns_uart_set_termios().
The behavior can also be easily verified by e.g. setting
CDNS_UART_CR_RX_DIS at the beginning of cdns_uart_handle_rx() - the
following loop will then get stuck.

Resetting the FIFO using RXRST would not set RXEMPTY either so simply
issuing a reset after RX-disable would not work.

I observe this frequently on a ZynqMP board during heavy RX load at 1M
baudrate when the reader process exits and thus RX gets disabled.

Fixes: 61ec901698 ("tty/serial: add support for Xilinx PS UART")
Signed-off-by: Anssi Hannula <anssi.hannula@bitwise.fi>
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-19 13:42:07 +01:00
Nava kishore Manne
260683137a serial: uartps: Fix interrupt mask issue to handle the RX interrupts properly
This patch Correct the RX interrupt mask value to handle the
RX interrupts properly.

Fixes: c8dbdc842d ("serial: xuartps: Rewrite the interrupt handling logic")
Signed-off-by: Nava kishore Manne <nava.manne@xilinx.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-12-19 08:23:20 +01:00
Michal Simek
32cf21ac4e serial: uartps: Fix error path when alloc failed
When cdns_uart_console allocation failed there is a need to also clear
ID from ID list.

Fixes: ae1cca3fa3 ("serial: uartps: Change uart ID port allocation")
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-12-19 08:23:20 +01:00
Shubhrajyoti Datta
82b1b2ec5d serial: uartps: Check if the device is a console
While checking for console_suspend_enabled also check if the
device is a console.

Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-12-19 08:23:20 +01:00
Shubhrajyoti Datta
86df8dd147 serial: uartps: Add the device_init_wakeup
Initialise the device wakeup.

The device_init_wakeup is needed for the wakeup to work by default.
Uart can be configured as the primary wakeup source so it is good to
enable wakeup by default.

The same functionality is enabled also by 8250_omap, atmel_serial,
omap-serial and stm32-usart.

Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-12-19 08:23:20 +01:00
Greg Kroah-Hartman
82ca0d5487 Revert "tty: xilinx_uartps: Correct return value in probe"
This reverts commit eca42d4cf3.

During review it was rejected, so drop it from the tree.

Cc: Rajan Vaja <RAJANV@xilinx.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-12-06 12:47:22 +01:00
Rajan Vaja
eca42d4cf3 tty: xilinx_uartps: Correct return value in probe
Existing driver checks for alternate clock if devm_clk_get() fails
and returns error code for last clock failure. If xilinx_uartps is
called before clock driver, devm_clk_get() returns -EPROBE_DEFER.
In this case, probe should not check for alternate clock as main
clock is already present in DTS and return -EPROBE_DEFER only.

This patch fixes it by not checking for alternate clock when main
clock get returns -EPROBE_DEFER.

Signed-off-by: Rajan Vaja <rajan.vaja@xilinx.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-12-05 11:02:38 +01:00
Anders Roxell
646097940a serial: set suppress_bind_attrs flag only if builtin
When the test 'CONFIG_DEBUG_TEST_DRIVER_REMOVE=y' is enabled,
arch_initcall(pl011_init) came before subsys_initcall(default_bdi_init).
devtmpfs gets killed because we try to remove a file and decrement the
wb reference count before the noop_backing_device_info gets initialized.

[    0.332075] Serial: AMBA PL011 UART driver
[    0.485276] 9000000.pl011: ttyAMA0 at MMIO 0x9000000 (irq = 39, base_baud = 0) is a PL011 rev1
[    0.502382] console [ttyAMA0] enabled
[    0.515710] Unable to handle kernel paging request at virtual address 0000800074c12000
[    0.516053] Mem abort info:
[    0.516222]   ESR = 0x96000004
[    0.516417]   Exception class = DABT (current EL), IL = 32 bits
[    0.516641]   SET = 0, FnV = 0
[    0.516826]   EA = 0, S1PTW = 0
[    0.516984] Data abort info:
[    0.517149]   ISV = 0, ISS = 0x00000004
[    0.517339]   CM = 0, WnR = 0
[    0.517553] [0000800074c12000] user address but active_mm is swapper
[    0.517928] Internal error: Oops: 96000004 [#1] PREEMPT SMP
[    0.518305] Modules linked in:
[    0.518839] CPU: 0 PID: 13 Comm: kdevtmpfs Not tainted 4.19.0-rc5-next-20180928-00002-g2ba39ab0cd01-dirty #82
[    0.519307] Hardware name: linux,dummy-virt (DT)
[    0.519681] pstate: 80000005 (Nzcv daif -PAN -UAO)
[    0.519959] pc : __destroy_inode+0x94/0x2a8
[    0.520212] lr : __destroy_inode+0x78/0x2a8
[    0.520401] sp : ffff0000098c3b20
[    0.520590] x29: ffff0000098c3b20 x28: 00000000087a3714
[    0.520904] x27: 0000000000002000 x26: 0000000000002000
[    0.521179] x25: ffff000009583000 x24: 0000000000000000
[    0.521467] x23: ffff80007bb52000 x22: ffff80007bbaa7c0
[    0.521737] x21: ffff0000093f9338 x20: 0000000000000000
[    0.522033] x19: ffff80007bbb05d8 x18: 0000000000000400
[    0.522376] x17: 0000000000000000 x16: 0000000000000000
[    0.522727] x15: 0000000000000400 x14: 0000000000000400
[    0.523068] x13: 0000000000000001 x12: 0000000000000001
[    0.523421] x11: 0000000000000000 x10: 0000000000000970
[    0.523749] x9 : ffff0000098c3a60 x8 : ffff80007bbab190
[    0.524017] x7 : ffff80007bbaa880 x6 : 0000000000000c88
[    0.524305] x5 : ffff0000093d96c8 x4 : 61c8864680b583eb
[    0.524567] x3 : ffff0000093d6180 x2 : ffffffffffffffff
[    0.524872] x1 : 0000800074c12000 x0 : 0000800074c12000
[    0.525207] Process kdevtmpfs (pid: 13, stack limit = 0x(____ptrval____))
[    0.525529] Call trace:
[    0.525806]  __destroy_inode+0x94/0x2a8
[    0.526108]  destroy_inode+0x34/0x88
[    0.526370]  evict+0x144/0x1c8
[    0.526636]  iput+0x184/0x230
[    0.526871]  dentry_unlink_inode+0x118/0x130
[    0.527152]  d_delete+0xd8/0xe0
[    0.527420]  vfs_unlink+0x240/0x270
[    0.527665]  handle_remove+0x1d8/0x330
[    0.527875]  devtmpfsd+0x138/0x1c8
[    0.528085]  kthread+0x14c/0x158
[    0.528291]  ret_from_fork+0x10/0x18
[    0.528720] Code: 92800002 aa1403e0 d538d081 8b010000 (c85f7c04)
[    0.529367] ---[ end trace 5a3dee47727f877c ]---

Rework to set suppress_bind_attrs flag to avoid removing the device when
CONFIG_DEBUG_TEST_DRIVER_REMOVE=y. This applies for pic32_uart and
xilinx_uartps as well.

Co-developed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Anders Roxell <anders.roxell@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-11-09 09:07:17 -08:00
Michal Simek
59eaeba63a of: base: Change logic in of_alias_get_alias_list()
Check compatible string first before setting up bit in bitmap to also
cover cases that allocated bitfield is not big enough.
Show warning about it but let driver to continue to work with allocated
bitfield to keep at least some devices (included console which
is commonly close to serial0) to work.

Fixes: b1078c355d ("of: base: Introduce of_alias_get_alias_list() to check alias IDs")
Fixes: ae1cca3fa3 ("serial: uartps: Change uart ID port allocation")
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-10-15 16:16:06 +02:00
Michal Simek
2088cfd882 serial: uartps: Do not allow use aliases >= MAX_UART_INSTANCES
Aliases >= MAX_UART_INSTANCES is no problem to find out and use but in
error path is necessary skip clearing bits in bitmap to ensure that only
bits in allocated bitmap are handled and nothing beyond that.
Without this patch when for example serial90 alias is used then in error
patch bit 90 is clear in 32bit wide bitmap.

Fixes: ae1cca3fa3 ("serial: uartps: Change uart ID port allocation")
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-10-11 19:59:29 +02:00
Wei Yongjun
823f4e53f0 serial: uartps: Fix missing unlock on error in cdns_get_id()
Add the missing unlock before return from function cdns_get_id()
in the error handling case.

Fixes: ae1cca3fa3 ("serial: uartps: Change uart ID port allocation")
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Reviewed-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-10-02 13:38:58 -07:00
Michal Simek
ae1cca3fa3 serial: uartps: Change uart ID port allocation
For IPs which have alias algorightm all the time using that alias and
minor number. It means serial20 alias ends up as ttyPS20.

If alias is not setup for probed IP instance the first unused position is
used but that needs to be checked if it is really empty because another
instance doesn't need to be probed at that time. of_alias_get_alias_list()
fills alias bitmap which exactly shows which ID is free.
If alias pointing to different not compatible IP, it is free to use.

cdns_get_id() call is placed below structure allocation to simplify
error path.

Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-09-20 13:49:53 +02:00
Michal Simek
6ac1b91f34 serial: uartps: Enable automatic flow control
Enable automatic flow control which should ensure that there is no
mainteinance in connection for zcu100 BT case.

Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Acked-by: Nava kishore Manne <navam@xilinx.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-09-18 16:07:23 +02:00
Michal Simek
bed25ac0e2 serial: uartps: Move Port ID to device data structure
Record port ID in device data structure to be have it connected to
certain instance.

Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-09-18 16:07:23 +02:00
Michal Simek
024ca329bf serial: uartps: Register own uart console and driver structures
Every instance is registering own struct console and struct uart_driver
with minor number which corresponds to alias ID (or 0 now) and with 1 uart
port. The same alias ID is saved to tty_driver->name_base which is key
field for creating ttyPSX name.

Because name_base and minor number are setup already there is no need to
setup any port->line number because 0 is the right value.

Unfortunately this driver is setting up major number to 0 for using
dynamic assignment and kernel is allocating different major numbers for
every instance instead of using the same major and different minor
number.

~# ls -la /dev/ttyPS*
crw-------    1 root     root      252,   0 Jan  1 03:36 /dev/ttyPS0
crw--w----    1 root     root      253,   1 Jan  1 00:00 /dev/ttyPS1

When major number is not 0. For example 252 then major/minor
combinations are in expected form

~# ls -la /dev/ttyPS*
crw-------    1 root     root      252,   0 Jan  1 04:04 /dev/ttyPS0
crw--w----    1 root     root      252,   1 Jan  1 00:00 /dev/ttyPS1

Driver is not freeing struct cdns_uart_console in case that instance is
not used as console. The reason is that console is incorrectly unregistred
and "console [0] disabled" message will be shown.

Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-09-18 16:07:23 +02:00