Commit Graph

7 Commits

Author SHA1 Message Date
Michael Trimarchi dc1972d027 i2c: Fix stuck transaction on cpm-i2c driver
When a process tries to read/write a disconnected i2c device, it receives a signal (e.g. ctrl-c) and the kernel gets stuck.

BUG: soft lockup - CPU#0 stuck for 61s! [I2CEEpromTest:392]
NIP: c01628f8 LR: c01628f0 CTR: c00177cc
REGS: c39abd70 TRAP: 0901   Not tainted  (2.6.25.7-alcore)
MSR: 00009032 <EE,ME,IR,DR>  CR: 42042048  XER: 20000000
TASK = c3889bd0[392] 'I2CEEpromTest' THREAD: c39aa000
GPR00: 00009000 c39abe20 c3889bd0 c39075c8 c39abe28 00000001 00000000 00000001
GPR08: c3889bd0 c39075c8 00009032 c39abe34 00002437
NIP [c01628f8] cpm_i2c_xfer+0x5fc/0x6d0
LR [c01628f0] cpm_i2c_xfer+0x5f4/0x6d0
Call Trace:
[c39abe20] [c0162924] cpm_i2c_xfer+0x628/0x6d0 (unreliable)
[c39abe90] [c015f6a0] i2c_transfer+0x88/0xb4
[c39abeb0] [c0160164] i2c_master_recv+0x48/0x6c
[c39abed0] [c01618dc] i2cdev_read+0x50/0xe4
[c39abef0] [c0068b24] vfs_read+0xc4/0x108
[c39abf10] [c0068f4c] sys_read+0x4c/0x90
[c39abf40] [c000d348] ret_from_syscall+0x0/0x38
Instruction dump:
3bc00064 92610010 3bf201c8 92810014 3b61

This happen because though the wait_event_interruptible_timeout takes the
signals into account, the driver does not handle them.
We propose to change the wait_event_interruptible_timeout with
wait_event_timeout, leaving the signals to be handled in other points
on the upper layers.

Signed-off-by: Bruno Morelli <bruno@evidence.eu.com>
Signed-off-by: Michael Trimarchi <michael@evidence.eu.com>
Acked-by: Jochen Friedrich <jochen@scram.de>
[ben-linux@fluff.org: fix title for patch]
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
2009-06-22 01:43:32 +01:00
Mark Ware 36521c271e i2c-cpm: Pass dev ptr to dma_*_coherent rather than NULL
Recent DMA changes result in a BUG() when NULL is passed to
dma_alloc_coherent in place of a device.

Signed-off-by: Mark Ware <mware@elphinstone.net>
[ben-linux@fluff.org: fix patch moves]
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
2009-05-12 00:36:04 +01:00
Mike Ditto a804644a1a i2c-cpm: Detect and report NAK right away instead of timing out
Make the driver report an ENXIO error immediately upon NAK instead of
waiting for another interrupt and getting a timeout.

When reading from a device that is not present or declines to respond
to, e.g., a non-existent register address, CPM immediately reports a
NAK condition in the TxBD, but the driver kept waiting until a timeout,
which takes 1 second and causes an ugly console error message.

Signed-off-by: Mike Ditto <mditto@consentry.com>
Acked-by: Jochen Friedrich <jochen@scram.de>
[ben-linux@fluff.org: reordered description text]
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
2008-12-16 20:17:09 +00:00
Wolfram Sang 0a346dacee i2c-cpm: Suppress autoprobing for devices
Similar to commit 618b26d528, also remove
automatic probing for this i2c controller. Might need updates to dts files
using it.

Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
Acked-by: Jochen Friedrich <jochen@scram.de>
Acked-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
2008-10-20 23:31:24 -05:00
Jean Delvare 3401b2fff3 i2c: Let bus drivers add SPD to their class
Let general purpose I2C/SMBus bus drivers add SPD to their class. Once
this is done, we will be able to tell the eeprom driver to only probe
for SPD EEPROMs and similar on these buses.

Note that I took a conservative approach here, adding I2C_CLASS_SPD to
many drivers that have no idea whether they can host SPD EEPROMs or not.
This is to make sure that the eeprom driver doesn't stop probing buses
where SPD EEPROMs or equivalent live.

So, bus driver maintainers and users should feel free to remove the SPD
class from drivers those buses never have SPD EEPROMs or they don't
want the eeprom driver to bind to them. Likewise, feel free to add the
SPD class to any bus driver I might have missed.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
2008-07-14 22:38:29 +02:00
Wolfram Sang 3b270804a9 i2c-cpm: Bugfixes
Bugfixes to the i2c-cpm driver

- enable correct interrupts (I2CER_TXE instead of I2CER_BUSY)
- replace forgotten iic with i2c
- prefix debug-output on init with 0x and add frequency

Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
Acked-by: Jochen Friedrich <jochen@scram.de>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
2008-07-14 22:38:28 +02:00
Jochen Friedrich 61045dbe9d i2c: Add support for I2C bus on Freescale CPM1/CPM2 controllers
This driver uses the port of 2.4 code from Vitaly Bordug
<vitb@kernel.crashing.org> and the actual algorithm used by the i2c
driver of the DBox code on cvs.tuxboc.org from Felix Domke
(tmbinc@gmx.net) and Gillem (htoa@gmx.net) converted to an
of_platform_driver. Tested on CPM1 (MPC823 on dbox2 hardware) and
CPM2 (MPC8272).

Signed-off-by: Jochen Friedrich <jochen@scram.de>
Tested-by: Wolfram Sang <w.sang@pengutronix.de>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
2008-07-14 22:38:27 +02:00