Commit graph

2631 commits

Author SHA1 Message Date
Mark Brown
60c1beeff4 Merge remote-tracking branches 'spi/fix/atmel', 'spi/fix/doc', 'spi/fix/dw', 'spi/fix/img-spfi', 'spi/fix/pl022' and 'spi/fix/ti-qspi' into spi-linus 2015-03-06 21:10:56 +00:00
Alexander Sverdlin
cd6fa8d2ca spi: pl022: Fix race in giveback() leading to driver lock-up
Commit fd316941c ("spi/pl022: disable port when unused") introduced a race,
which leads to possible driver lock up (easily reproducible on SMP).

The problem happens in giveback() function where the completion of the transfer
is signalled to SPI subsystem and then the HW SPI controller is disabled. Another
transfer might be setup in between, which brings driver in locked-up state.

Exact event sequence on SMP:

core0                                   core1

                                        => pump_transfers()
                                        /* message->state == STATE_DONE */
                                          => giveback()
                                            => spi_finalize_current_message()

=> pl022_unprepare_transfer_hardware()
=> pl022_transfer_one_message
  => flush()
  => do_interrupt_dma_transfer()
    => set_up_next_transfer()
    /* Enable SSP, turn on interrupts */
    writew((readw(SSP_CR1(pl022->virtbase)) |
           SSP_CR1_MASK_SSE), SSP_CR1(pl022->virtbase));

...

=> pl022_interrupt_handler()
  => readwriter()

                                        /* disable the SPI/SSP operation */
                                        => writew((readw(SSP_CR1(pl022->virtbase)) &
                                                  (~SSP_CR1_MASK_SSE)), SSP_CR1(pl022->virtbase));

Lockup! SPI controller is disabled and the data will never be received. Whole
SPI subsystem is waiting for transfer ACK and blocked.

So, only signal transfer completion after disabling the controller.

Fixes: fd316941c (spi/pl022: disable port when unused)
Signed-off-by: Alexander Sverdlin <alexander.sverdlin@nokia.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Cc: stable@vger.kernel.org
2015-03-06 19:45:55 +00:00
Andy Shevchenko
c9dafb27c8 spi: dw-mid: avoid potential NULL dereference
When DMA descriptor allocation fails we should not try to assign any fields in
the bad descriptor. The patch adds the necessary checks for that.

Fixes: 7063c0d942 (spi/dw_spi: add DMA support)
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Cc: stable@vger.kernel.org
2015-03-06 11:23:26 +00:00
Sifan Naeem
f165ed6337 spi: img-spfi: Verify max spfi transfer length
Maximum transfer length supported by SPFI is 65535, this is limited
by the number of bits available in SPFI TSize register to represent
the transfer size.
For transfer requests larger than the maximum supported the driver
will return an invalid argument error.

Signed-off-by: Sifan Naeem <sifan.naeem@imgtec.com>
Reviewed-by: Andrew Bresticker <abrestic@chromium.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
2015-03-03 14:26:34 +00:00
Torsten Fleischer
76e1d14b31 spi: atmel: Fix interrupt setup for PDC transfers
Additionally to the current DMA transfer the PDC allows to set up a next DMA
transfer. This is useful for larger SPI transfers.

The driver currently waits for ENDRX as end of the transfer. But ENDRX is set
when the current DMA transfer is done (RCR = 0), i.e. it doesn't include the
next DMA transfer.
Thus a subsequent SPI transfer could be started although there is currently a
transfer in progress. This can cause invalid accesses to the SPI slave devices
and to SPI transfer errors.

This issue has been observed on a hardware with a M25P128 SPI NOR flash.

So instead of ENDRX we should wait for RXBUFF. This flag is set if there is
no more DMA transfer in progress (RCR = RNCR = 0).

Signed-off-by: Torsten Fleischer <torfl6749@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Cc: stable@vger.kernel.org
2015-02-26 11:34:23 +09:00
Andy Shevchenko
9d239d353c spi: dw: revisit FIFO size detection again
The commit d297933cc7 (spi: dw: Fix detecting FIFO depth) tries to fix the
logic of the FIFO detection based on the description on the comments. However,
there is a slight difference between numbers in TX Level and TX FIFO size.

So, by specification the FIFO size would be in a range 2-256 bytes. From TX
Level prospective it means we can set threshold in the range 0-(FIFO size - 1)
bytes. Hence there are currently two issues:
  a) FIFO size 2 bytes is actually skipped since TX Level is 1 bit and could be
     either 0 or 1 byte;
  b) FIFO size is incorrectly decreased by 1 which already done by meaning of
     TX Level register.

This patch fixes it eventually right.

Fixes: d297933cc7 (spi: dw: Fix detecting FIFO depth)
Reviewed-by: Axel Lin <axel.lin@ingics.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Cc: stable@vger.kernel.org
2015-02-26 11:09:51 +09:00
Andy Shevchenko
307ed83c8c spi: dw-pci: correct number of chip selects
The commit d58cf5ff65 brought a second controller to the list of supported
devices and changed a number of the chip selects. Besides the previous number
was wrong anyway the mentioned patch makes it wrong again meanwhile has a
proper numbers in the commit message. Indeed, SPI1 has 5 bits and SPI2 has 2
bits, but it does not mean to have power of two of this bits as a possible
number of the chip selects. So, this patch fixes it eventually.

Fixes: d58cf5ff65 (spi: dw-pci: describe Intel MID controllers better)
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Cc: stable@vger.kernel.org
2015-02-24 16:59:32 +09:00
Mugunthan V N
0061104764 drivers: spi: ti-qspi: wait for busy bit clear before data write/read
Data corruption is seen while reading/writing large data from/to qspi
device because the data register is over written or read before data
is ready which is denoted by busy bit in status register. SO adding
a busy bit check before writing/reading data to/from qspi device.

Signed-off-by: Mugunthan V N <mugunthanvnm@ti.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2015-02-21 18:29:09 +09:00
Linus Torvalds
b11a278397 Merge branch 'kconfig' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild
Pull kconfig updates from Michal Marek:
 "Yann E Morin was supposed to take over kconfig maintainership, but
  this hasn't happened.  So I'm sending a few kconfig patches that I
  collected:

   - Fix for missing va_end in kconfig
   - merge_config.sh displays used if given too few arguments
   - s/boolean/bool/ in Kconfig files for consistency, with the plan to
     only support bool in the future"

* 'kconfig' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild:
  kconfig: use va_end to match corresponding va_start
  merge_config.sh: Display usage if given too few arguments
  kconfig: use bool instead of boolean for type definition attributes
2015-02-19 10:36:45 -08:00
Joe Perches
f7219b527b treewide: Remove unnecessary BCMA_CORETABLE_END macro
Use the normal {} instead of a macro to terminate an array.

Remove the macro too.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-02-11 14:38:28 -08:00
Mark Brown
66886337bf Merge remote-tracking branch 'spi/topic/xilinx' into spi-next 2015-02-08 11:17:01 +08:00
Mark Brown
30b9278bf5 Merge remote-tracking branches 'spi/topic/sirf', 'spi/topic/spidev', 'spi/topic/st-ssc' and 'spi/topic/ti-qspi' into spi-next 2015-02-08 11:16:58 +08:00
Mark Brown
4f9f4548a5 Merge remote-tracking branches 'spi/topic/orion', 'spi/topic/pxa2xx', 'spi/topic/qup', 'spi/topic/rockchip' and 'spi/topic/samsung' into spi-next 2015-02-08 11:16:55 +08:00
Mark Brown
8328509c4b Merge remote-tracking branches 'spi/topic/img-spfi', 'spi/topic/imx', 'spi/topic/inline', 'spi/topic/meson' and 'spi/topic/mxs' into spi-next 2015-02-08 11:16:52 +08:00
Mark Brown
d6cd09bea9 Merge remote-tracking branches 'spi/topic/falcon', 'spi/topic/fsf', 'spi/topic/fsl', 'spi/topic/fsl-dspi' and 'spi/topic/gpio' into spi-next 2015-02-08 11:16:46 +08:00
Mark Brown
fab4b42a9a Merge remote-tracking branches 'spi/topic/atmel', 'spi/topic/config', 'spi/topic/dln2' and 'spi/topic/dw' into spi-next 2015-02-08 11:16:43 +08:00
Mark Brown
81306d53da Merge remote-tracking branch 'spi/topic/sh-msiof' into spi-next 2015-02-08 11:16:43 +08:00
Mark Brown
f69c22ed22 Merge remote-tracking branch 'spi/topic/core' into spi-next 2015-02-08 11:16:42 +08:00
Nicholas Mc Guire
f2234691d7 spi: mxs: cleanup wait_for_completion return handling
return type of wait_for_completion_timeout is unsigned long not int, this
patch uses the return value of wait_for_completion_timeout in the condition
directly rather than adding a additional appropriately typed variable.

Signed-off-by: Nicholas Mc Guire <hofrat@osadl.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
2015-02-05 18:04:57 +00:00
Nicholas Mc Guire
060556a9bd spi: ti-qspi: cleanup wait_for_completion return handling
return type of wait_for_completion_timeout is unsigned long not int, this
patch uses the return value of wait_for_completion_timeout in the condition
directly rather than assigning it to an incorrect type variable.

Signed-off-by: Nicholas Mc Guire <hofrat@osadl.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
2015-02-05 18:04:03 +00:00
Mark Brown
d426a842b0 Merge remote-tracking branches 'spi/fix/fsl-dspi' and 'spi/fix/imx' into spi-linus 2015-02-04 20:57:31 +00:00
Nicholas Mc Guire
56536a7ff5 spi: spi-imx: cleanup wait_for_completion handling
return type of wait_for_completion_timeout is unsigned long not int and
always returns >=0 , this patch adds a suitable return variable and
simplifies the return value checking as there is no < 0 case.

Signed-off-by: Nicholas Mc Guire <hofrat@osadl.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
2015-02-04 20:53:15 +00:00
Nicholas Mc Guire
19f0ad0942 spi: sh-msiof: cleanup wait_for_completion return handling
return type of wait_for_completion_timeout is unsigned long not int, this
patch uses the return value of wait_for_completion_timeout in the condition
directly rather than assigning it to an incorrect type variable.

Signed-off-by: Nicholas Mc Guire <der.herr@hofr.at>
Signed-off-by: Mark Brown <broonie@kernel.org>
2015-02-04 20:52:53 +00:00
Nicholas Mc Guire
682a71b284 spi: match var type to return type of wait_for_completion
return type of wait_for_completion_timeout is unsigned long not int, this
patch changes the type of m from int to unsigned long.

Signed-off-by: Nicholas Mc Guire <der.herr@hofr.at>
Signed-off-by: Mark Brown <broonie@kernel.org>
2015-02-04 20:52:32 +00:00
Rob Herring
9064bf3c3c spi: spi-pxa2xx: only include mach/dma.h for legacy DMA
Move the include of mach/dma.h to the legacy PXA DMA code where it is used.
This enables building spi-pxa2xx on ARM64.

Signed-off-by: Rob Herring <robh@kernel.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
2015-02-04 20:14:26 +00:00
Nicholas Mc Guire
1369dea649 spi: atmel: cleanup wait_for_completion return handling
return type of wait_for_completion_timeout is unsigned long not int, this
patch adds an appropriate variable and fixes up the assignment. It removes
the else branch as the only thing it was doing is assigning ret = 0; - but
ret is never used thereafter so that is not needed. As the string in
dev_err already states "timeout" there is little point in printing the 0.
A typo in "trasfer" -> transfer is also fixed.

Signed-off-by: Nicholas Mc Guire <hofrat@osadl.org>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2015-02-04 11:26:03 +00:00
Robin Gong
a02bb401f8 spi: imx: use pio mode for i.mx6dl
For TKT238285 hardware issue which may cause txfifo store data twice can only
be caught on i.mx6dl, we use pio mode instead of DMA mode on i.mx6dl.

Fixes: f62caccd12 (spi: spi-imx: add DMA support)
Signed-off-by: Robin Gong <b38343@freescale.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Cc: stable@vger.kernel.org
2015-02-03 12:17:01 +00:00
Bhuvanchandra DV
ceadfd8de0 spi: fsl-dspi: Remove possible memory leak of 'chip'
Move the check for spi->bits_per_word
before allocation, to avoid memory leak.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Bhuvanchandra DV <bhuvanchandra.dv@toradex.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2015-02-02 20:05:19 +00:00
Nobuhiro Iwamatsu
65d5665bb2 spi: sh-msiof: Update calculation of frequency dividing
sh-msiof of frequency dividing does not perform the calculation, driver have
to manage setting value in the table. It is not possible to set frequency
dividing value close to the actual data in this way. This changes from
frequency dividing of table management to setting by calculation.
This driver is able to set a value close to the actual data.

Signed-off-by: Nobuhiro Iwamatsu <nobuhiro.iwamatsu.yj@renesas.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2015-02-02 20:03:39 +00:00
Ian Abbott
7782a1a948 spi: spidev: Convert buf pointers for 32-bit compat SPI_IOC_MESSAGE(n)
The SPI_IOC_MESSAGE(n) ioctl commands' argument points to an array of n
struct spi_ioc_transfer elements.  The spidev's compat_ioctl handler
just converts this pointer and passes it on to the unlocked_ioctl
handler to process it.

The tx_buf and rx_buf members of struct spi_ioc_transfer are of type
__u64 and hold pointer values.  A 32-bit userspace application running
in a 64-bit kernel might not have widened the 32-bit pointers correctly
for the kernel.  The application might have sign-extended the pointer to
when the kernel expects it to be zero-extended, or vice versa, leading
to an -EFAULT being returned by spidev_message() if the widened pointer
is invalid.

Handle the SPI_IOC_MESSAGE(n) ioctl commands specially in the
compat_ioctl handler, calling new function spidev_compat_ioctl_message()
to handle them.  This processes them in the same way as the
unlocked_ioctl handler except that it uses compat_ptr() to convert the
tx_buf and rx_buf members of each struct spi_ioc_transfer element.

To save code, factor out part of the unlocked_ioctl handler into a new
function spidev_get_ioc_message().  This checks the ioctl command code
is a valid SPI_IOC_MESSAGE(n), determines n and copies the array of n
struct spi_ioc_transfer elements from userspace into dynamically
allocated memory, returning either a pointer to the memory, an
ERR_PTR(-err) value, or NULL (for SPI_IOC_MESSAGE(0)).

Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Mark Brown <broonie@kernel.org>
2015-02-02 19:57:19 +00:00
Ricardo Ribalda Delgado
34093cb97a spi/xilinx: Fix access invalid memory on xilinx_spi_tx
On 1 and 2 bytes per word, the transfer of the 3 last bytes will access
memory outside tx_ptr.

Although this has not trigger any error on real hardware, we should
better fix this.

Fixes: 24ba5e593f (Remove rx_fn and tx_fn pointer)
Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2015-02-02 12:17:19 +00:00
Mark Brown
0635287a30 spi: Revert "spi/xilinx: Remove iowrite/ioread wrappers"
This reverts commit 99082eab63 since it
breaks the build due to differing implementations of iowrite() and
ioread().

Signed-off-by: Mark Brown <broonie@kernel.org>
2015-01-30 13:42:00 +01:00
Ricardo Ribalda
eb25f16c6f spi/xilinx: Check number of slaves range
The core only supports up to 32 slaves, and the chipselect function
expects the same.

Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2015-01-28 19:57:32 +00:00
Ricardo Ribalda Delgado
22417352f6 spi/xilinx: Use polling mode on small transfers
Small transfers generally can be accomplished faster in polling mode.
This patch select the transfer which size is bellow the buffer size to
be done on polling mode

Suggested-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2015-01-28 19:42:43 +00:00
Ricardo Ribalda Delgado
b563bfb8d7 spi/xilinx: Remove remaining_words driver data variable
The variable never leaves the scope of txrx_bufs.

Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2015-01-28 19:42:43 +00:00
Ricardo Ribalda Delgado
99082eab63 spi/xilinx: Remove iowrite/ioread wrappers
Save a stack level and cleanup code.

Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2015-01-28 19:42:43 +00:00
Ricardo Ribalda Delgado
17aaaa8032 spi/xilinx: Convert bits_per_word in bytes_per_word
Simplify the code by using the unit used on most of the code logic.

Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2015-01-28 19:42:43 +00:00
Ricardo Ribalda Delgado
d79b2d073a spi/xilinx: Convert remainding_bytes in remaining words
Simplify the code by using the unit used on most of the code logic.

Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2015-01-28 19:42:43 +00:00
Ricardo Ribalda Delgado
c30929415a spi/xilinx: Make spi_tx and spi_rx simmetric
spi_rx handles the case where the buffer is null. Nevertheless spi_tx
did not handle it, and was handled by the caller function.

Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2015-01-28 19:42:43 +00:00
Ricardo Ribalda Delgado
24ba5e593f spi/xilinx: Remove rx_fn and tx_fn pointer
Simplify the code by removing the tx and and rx function pointers and
substitute them by a single function.

Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2015-01-28 19:42:42 +00:00
Ricardo Ribalda Delgado
f9c6ef6cfe spi/xilinx: Support for spi mode CS_HIGH
The core controls the chip select lines individually.

By default, all the lines are consider active_low. After
spi_setup_transfer, it has its real value.

Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2015-01-28 19:42:42 +00:00
Ricardo Ribalda Delgado
d9f5881242 spi/xilinx: Do not inhibit transmission in polling mode
When no irq is used, there is no need to inhibit the transmission for
every transaction. This inhibition was implemented to avoid a race
condition with the irq handler.

Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2015-01-28 19:42:42 +00:00
Ricardo Ribalda Delgado
5fe11cc09c spi/xilinx: Support cores with no interrupt
The core can run in polling mode. In fact, the performance of the core
is similar (or even better), due to the fact most of the spi
transactions are just a couple of bytes and there is one irq per
transactions.

When an mtd device is connected via spi, reading 8MB of data produces
more than 80K interrupts (with irq disabling, context swith....)

Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2015-01-28 19:42:42 +00:00
Ricardo Ribalda Delgado
5b74d7a3b8 spi/xilinx: Use cached value of register
The control register has not changed since the previous access.
Therefore we can use the cached value and safe one bus access.

Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2015-01-28 19:42:42 +00:00
Ricardo Ribalda Delgado
a87cbca0ac spi/xilinx: Code cleanup
On the transmission loop, check for remaining bytes at the loop
condition.

This way we can handle transmissions of 0 bytes and clean the code.

Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2015-01-28 19:42:42 +00:00
Ricardo Ribalda Delgado
899929baba spi/xilinx: Leave the IRQ always enabled.
Instead of enabling the IRQ and disabling it for every transaction.

Specially the small transactions (1,2 words) benefit from removing 3 bus
accesses.

Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2015-01-28 19:42:42 +00:00
Ricardo Ribalda Delgado
4c9a761402 spi/xilinx: Simplify spi_fill_tx_fifo
Instead of checking the TX_FULL flag for every transaction, find out the
size of the buffer at probe time and use it.

To avoid situations where the core had some data on the buffer before
initialization, the core is reseted before the buffer size is detected

Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2015-01-28 19:42:42 +00:00
Chao Fu
9298bc7273 spi: spi-fsl-dspi: Remove spi-bitbang
DSPI module need cs change information in
a spi transfer. According to cs change, DSPI
will give last data the right flag. Bitbang
provide cs change behind the last data in
a transfer. So DSPI can not deal the last
data in every transfer properly, so remove
the bitbang in the driver.

Signed-off-by: Bhuvanchandra DV <bhuvanchandra.dv@toradex.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2015-01-28 19:25:17 +00:00
Arnd Bergmann
75d30c51f8 spi: pl08x: do not select S3C64XX_PL080
The pl08x driver originally selected S3C64XX_PL080 to avoid having
the legacy Samsung DMA interfaces. Those are now gone, so the
select is no longer needed, but it now causes problems when
CONFIG_DMA_ENGINE is disabled:

arch/arm/plat-samsung/built-in.o: In function `s3c64xx_spi0_set_platdata':
:(.init.text+0x518): undefined reference to `pl08x_filter_id'

This simply removes the 'select' to avoid this problem.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Mark Brown <broonie@kernel.org>
2015-01-28 17:37:16 +00:00
Arnd Bergmann
97cf56697a spi/rockchip: avoid uninitialized-use warning
We currently get a warning about potentially uninitialized variables
in the rockchip spi driver, at least in certain toolchain versions:

spi/spi-rockchip.c: In function 'rockchip_spi_prepare_dma':
include/linux/dmaengine.h:796:2: warning: 'txdesc' may be used uninitialized in this function
include/linux/dmaengine.h:796:2: warning: 'rxdesc' may be used uninitialized in this function

The reason seems to be that gcc cannot know whether the value
of the rs->rx and rs->tx variables change between the two points
these are accessed.

The code is actually correct, but to make this clearer to the
compiler, this changes the conditionals to test for the local
rxdesc/txdesc variables instead, which it knows won't change.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Mark Brown <broonie@kernel.org>
2015-01-28 17:36:37 +00:00