linux-stable.git/drivers/i2c, branch v3.9.4

i2c: designware: always clear interrupts before enabling them

2013-05-24T18:35:47+00:00

commit 2a2d95e9d6d29e726cc294b65391917ed2e32bf4 upstream.

If the I2C bus is put to a low power state by an ACPI method it might pull
the SDA line low (as its power is removed). Once the bus is put to full
power state again, the SDA line is pulled back to high. This transition
looks like a STOP condition from the controller point-of-view which sets
STOP detected bit in its status register causing the driver to fail
subsequent transfers.

Fix this by always clearing all interrupts before we start a transfer.

Signed-off-by: Mika Westerberg 
Signed-off-by: Wolfram Sang 
Signed-off-by: Greg Kroah-Hartman

i2c: designware: fix RX FIFO overrun

2013-05-24T18:35:47+00:00

commit e6f34cea56f5b95498070eaa9f4aa3ba4a9e4f62 upstream.

i2c_dw_xfer_msg() pushes a number of bytes to transmit/receive
to/from the bus into the TX FIFO.
For master-rx transactions, the maximum amount of data that can be
received is calculated depending solely on TX and RX FIFO load.

This is racy - TX FIFO may contain master-rx data yet to be
processed, which will eventually land into the RX FIFO. This
data is not taken into account and the function may request more
data than the controller is actually capable of storing.

This patch ensures the driver takes into account the outstanding
master-rx data in TX FIFO to prevent RX FIFO overrun.

Signed-off-by: Josef Ahmad 
Acked-by: Mika Westerberg 
Signed-off-by: Wolfram Sang 
Signed-off-by: Greg Kroah-Hartman

i2c: xiic: must always write 16-bit words to TX_FIFO

2013-05-08T03:33:08+00:00

commit c39e8e4354ce4daf23336de5daa28a3b01f00aa6 upstream.

The TX_FIFO register is 10 bits wide.  The lower 8 bits are the data to be
written, while the upper two bits are flags to indicate stop/start.

The driver apparently attempted to optimize write access, by only writing a
byte in those cases where the stop/start bits are zero.  However, we have
seen cases where the lower byte is duplicated onto the upper byte by the
hardware, which causes inadvertent stop/starts.

This patch changes the write access to the transmit FIFO to always be 16 bits
wide.

Signed off by: Steven A. Falco 
Signed-off-by: Wolfram Sang 
Signed-off-by: Greg Kroah-Hartman

ACPI / I2C: Use parent's ACPI_HANDLE() in acpi_i2c_register_devices()

2013-04-02T13:30:41+00:00

The ACPI handle of struct i2c_adapter's dev member should not be
set, because this causes that struct i2c_adapter to be associated
with the ACPI device node corresponding to its parent as the
second "physical_device", which is incorrect (this happens during
the registration of struct i2c_adapter).  Consequently,
acpi_i2c_register_devices() should use the ACPI handle of the
parent of the struct i2c_adapter it is called for rather than the
struct i2c_adapter's ACPI handle (which should be NULL).

Make that happen and modify the i2c-designware-platdrv driver,
which currently is the only driver for ACPI-enumerated I2C
controller chips, not to set the ACPI handle for the
struct i2c_adapter it creates.

Signed-off-by: Rafael J. Wysocki 
Reviewed-by: Aaron Lu 
Acked-by: Mika Westerberg 
Acked-by: Wolfram Sang

Merge branch 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux

2013-03-23T19:32:14+00:00

Pull i2c fixes from Wolfram Sang:
 "One bugfix for the tegra driver.  Two updates regarding email
  addresses and MAINTAINERS which I like to have up-to-date so people
  can be reached immediately.  While we are here, there is on PCI_ID
  addition."

* 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux:
  MAINTAINERS: add maintainer entry for atmel i2c driver
  i2c: Fix my e-mail address in drivers and documentation
  i2c: iSMT: add Intel Avoton DeviceIDs
  i2c: tegra: check the clk_prepare_enable() return value

i2c: Fix my e-mail address in drivers and documentation

2013-03-22T10:18:34+00:00

My old e-mail address is no longer working.

Signed-off-by: Guenter Roeck 
Signed-off-by: Wolfram Sang

i2c: iSMT: add Intel Avoton DeviceIDs

2013-03-22T10:16:15+00:00

This patch adds the iSMT SMBus Controller DeviceIDs for the Intel Avoton SOC.

Signed-off-by: Seth Heasley 
Acked-by: Neil Horman 
Signed-off-by: Wolfram Sang

i2c: tegra: check the clk_prepare_enable() return value

2013-03-22T09:28:55+00:00

NVIDIA's Tegra SoC allows read/write of controller register only
if controller clock is enabled. System hangs if read/write happens
to registers without enabling clock.

clk_prepare_enable() can be fail due to unknown reason and hence
adding check for return value of this function. If this function
success then only access register otherwise return to caller with
error.

Signed-off-by: Laxman Dewangan 
Reviewed-by: Stephen Warren 
Signed-off-by: Wolfram Sang 
Cc: stable@kernel.org

drivers/i2c: remove !S390 dependency, add missing GENERIC_HARDIRQS dependencies

2013-03-11T08:59:02+00:00

Remove !S390 dependency from i2c Kconfig, since s390 now supports PCI, HAS_IOMEM
and HAS_DMA, however we need to add a couple of GENERIC_HARDIRQS dependecies to
fix compile and link errors like these:

ERROR: "devm_request_threaded_irq" [drivers/i2c/i2c-smbus.ko] undefined!
ERROR: "devm_request_threaded_irq" [drivers/i2c/busses/i2c-ocores.ko] undefined!

Cc: Wolfram Sang 
Cc: Jean Delvare 
Signed-off-by: Heiko Carstens 
Signed-off-by: Martin Schwidefsky

idr: remove MAX_IDR_MASK and move left MAX_IDR_* into idr.c

2013-02-28T03:10:20+00:00

MAX_IDR_MASK is another weirdness in the idr interface.  As idr covers
whole positive integer range, it's defined as 0x7fffffff or INT_MAX.

Its usage in idr_find(), idr_replace() and idr_remove() is bizarre.
They basically mask off the sign bit and operate on the rest, so if
the caller, by accident, passes in a negative number, the sign bit
will be masked off and the remaining part will be used as if that was
the input, which is worse than crashing.

The constant is visible in idr.h and there are several users in the
kernel.

* drivers/i2c/i2c-core.c:i2c_add_numbered_adapter()

  Basically used to test if adap->nr is a negative number which isn't
  -1 and returns -EINVAL if so.  idr_alloc() already has negative
  @start checking (w/ WARN_ON_ONCE), so this can go away.

* drivers/infiniband/core/cm.c:cm_alloc_id()
  drivers/infiniband/hw/mlx4/cm.c:id_map_alloc()

  Used to wrap cyclic @start.  Can be replaced with max(next, 0).
  Note that this type of cyclic allocation using idr is buggy.  These
  are prone to spurious -ENOSPC failure after the first wraparound.

* fs/super.c:get_anon_bdev()

  The ID allocated from ida is masked off before being tested whether
  it's inside valid range.  ida allocated ID can never be a negative
  number and the masking is unnecessary.

Update idr_*() functions to fail with -EINVAL when negative @id is
specified and update other MAX_IDR_MASK users as described above.

This leaves MAX_IDR_MASK without any user, remove it and relocate
other MAX_IDR_* constants to lib/idr.c.

Signed-off-by: Tejun Heo 
Cc: Jean Delvare 
Cc: Roland Dreier 
Cc: Sean Hefty 
Cc: Hal Rosenstock 
Cc: "Marciniszyn, Mike" 
Cc: Jack Morgenstein 
Cc: Or Gerlitz 
Cc: Al Viro 
Acked-by: Wolfram Sang 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds