Commit graph

2043 commits

Author SHA1 Message Date
Guennadi Liakhovetski
b45b262cef dmaengine: add a driver for AMBA AXI NBPF DMAC IP cores
This patch adds a driver for NBPF DMAC IP cores from Renesas, designed for
the AMBA AXI bus.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski+renesas@gmail.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2014-08-04 13:30:31 +05:30
Peter Ujfalusi
ed64610f29 dmaengine: edma: Do not register second device when booted with DT
DT boot does not yet support more than one edma device. To avoid issues at
runtime we should not register the second device when the kernel is booted
with DT.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2014-07-31 17:27:47 +05:30
Peter Ujfalusi
04d537d95e dmaengine: edma: Do not change the error code returned from edma_alloc_slot
In case of edma_alloc_slot() failure during probe we should return the error
unchanged to make debugging easier.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2014-07-31 17:27:47 +05:30
Laurent Pinchart
4415b03abb dmaengine: shdma: Allocate cyclic sg list dynamically
The sg list used to prepare cyclic DMA descriptors is currently
allocated statically on the stack as an array of 32 elements. This makes
the shdma_prep_dma_cyclic() function consume a lot of stack space, as
reported by the compiler:

drivers/dma/sh/shdma-base.c: In function ‘shdma_prep_dma_cyclic’:
drivers/dma/sh/shdma-base.c:715:1: warning: the frame size of 1056 bytes
is larger than 1024 bytes [-Wframe-larger-than=]

Given the limited Linux kernel stack size, this could lead to stack
overflows. Fix the problem by allocating the sg list dynamically.

Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2014-07-31 17:15:45 +05:30
Laurent Pinchart
c091ff51b4 dmaengine: shdma: Make channel filter ignore unrelated devices
The shdma_chan_filter() function relies on the DMA channel being
embedded in an shdma_chan structure. If this assumption isn't true, for
instance when the system contains DMA channels supported by an unrelated
driver, the function will crash.

Avoid this by returning false directly when the channel belongs to an
unrelated device.

Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2014-07-31 17:15:45 +05:30
Laurent Pinchart
9f2c2bb312 dmaengine: sh: Rework Kconfig and Makefile
Separate helpers and drivers in the Kconfig and Makefile to improve
readability and move the CONFIG_OF dependency from the Makefile to
Kconfig.

[pebolle@tiscali.nl: reported need to rename SHDMA_R8A73A4 instances]
Reported-by: Paul Bolle <pebolle@tiscali.nl>
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
[horms+renesas@verge.net.au: squashed rename of SHDMA_R8A73A4 instances]
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2014-07-31 17:15:45 +05:30
Maxime Ripard
4fbd804e00 dmaengine: sun6i: Fix memory leaks
The sun6i_dma_prep_memcpy and sun6i_dma_prep_slave_sg functions were both
leaking the descriptor they allocated if an  error was happening after a
successful dma_pool_alloc call.

It also fixes a memleak that was happening in the scatter gather list
traversal, that was allocating as much descriptor as there was scatter gather
items, but only freeing the current descriptor if an error was to arise.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2014-07-30 19:14:17 +05:30
Maxime Ripard
174427c1bb dmaengine: sun6i: Free the interrupt before killing the tasklet
There's still a small window between the call to sun6i_kill_tasklet and the end
of the driver remove function where a spurious interrupt might trigger, and
start using deallocated resources.

Replace the call to synchronize_irq by a free_irq, so that we're sure that we
won't get any further interrupts when we're deallocating resources.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2014-07-30 19:14:17 +05:30
Maxime Ripard
92e4a3bf38 dmaengine: sun6i: Remove switch statement from buswidth convertion routine
Since the conversion routine is quite trivial, we don't need this switch, and
we can just use a simple calculation.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2014-07-30 19:14:17 +05:30
Alexander Popov
2795eedf2f dmaengine: of: kconfig: select DMA_ENGINE when DMA_OF is selected
Select DMA_ENGINE when DMA_OF is selected since
of_dma_xlate_by_chan_id() from drivers/dma/of-dma.c uses
dma_get_slave_channel() from drivers/dma/dmaengine.c

This resolves error reported:

drivers/built-in.o: In function `of_dma_xlate_by_chan_id':
drivers/dma/of-dma.c:253: undefined reference to `dma_get_slave_channel'

Signed-off-by: Alexander Popov <a13xp0p0v88@gmail.com>
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2014-07-30 19:06:55 +05:30
Vinod Koul
db0e701819 Merge commit 'renesas-rcar-audmapp-for-v3.17' into for-linus 2014-07-28 17:26:36 +05:30
Peter Ujfalusi
8e8805d5bf dmaengine: edma: Serve cyclic (audio) channels with high priority queue
Move the DMA channel used in cyclic mode (audio) to the highest priority
event queue which helps to reduce audio problems.
When the channel is terminated, move it back to the default queue.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2014-07-28 17:03:16 +05:30
Peter Ujfalusi
a1f146f317 dmaengine: edma: Support to suppress the period interrupts in cyclic mode
If the client (audio) does not request interrupts for every period we can
disable them.
With updated audio driver stack we can play audio w/o the need to process
any edma interrupts.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2014-07-28 17:02:53 +05:30
Peter Ujfalusi
b7f9bc5267 dmaengine: edma: Update caps->residue_granularity to match with reality
The edma can report accurate DMA position so update the residue_granularity
to DMA_RESIDUE_GRANULARITY_BURST.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2014-07-28 17:02:33 +05:30
Vinod Koul
7f5e03e736 dmaengine: sun61: fix warning on bad print specfier
The sg_dma_len() returns unsigned int but we had driver print it as %zu, use
%u as documented in Documentation/printk-formats.txt

drivers/dma/sun6i-dma.c: In function ‘sun6i_dma_prep_slave_sg’:
drivers/dma/sun6i-dma.c:643: warning: format ‘%zu’ expects type ‘size_t’,
but argument 8 has type ‘unsigned int’
drivers/dma/sun6i-dma.c:661: warning: format ‘%zu’ expects type ‘size_t’,
but argument 8 has type ‘unsigned int’

Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2014-07-28 12:49:59 +05:30
Vinod Koul
42c0d54e62 dmaengine: sun6i: fix build failure on x86, xilinx targets
Since the driver defined COMPILE_TEST, it gets compiled for different arch's
The driver uses __virt_to_phys() insteadof virt_to_phys, so replace it

drivers/dma/sun6i-dma.c: In function ‘sun6i_dma_dump_chan_regs’:
drivers/dma/sun6i-dma.c:203: error: implicit declaration of function '__virt_to_phys'

Reported-by: kbuild test robot <fengguang.wu@intel.com>
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2014-07-28 12:49:33 +05:30
Alexander Popov
ec1f0c9666 dmaengine: mpc512x: register for device tree channel lookup
Register the controller for device tree based lookup of DMA channels
(non-fatal for backwards compatibility with older device trees) and
provide the '#dma-cells' property in the shared mpc5121.dtsi file

Signed-off-by: Alexander Popov <a13xp0p0v88@gmail.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2014-07-26 00:21:42 +05:30
Alexander Popov
16369efb1f dmaengine: of: add common xlate function for matching by channel id
This patch adds a new common OF dma xlate callback function which will match a
channel by it's id. The binding expects one integer argument which it will use to
lookup the channel by the id.

Unlike of_dma_simple_xlate this function is able to handle a system with
multiple DMA controllers. When registering the of dma provider with
of_dma_controller_register a pointer to the dma_device struct which is
associated with the dt node needs to passed as the data parameter.
New function will use this pointer to match only channels which belong to the
specified DMA controller.

Signed-off-by: Alexander Popov <a13xp0p0v88@gmail.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2014-07-26 00:21:41 +05:30
Maxime Ripard
5558593087 dmaengine: sun6i: Add driver for the Allwinner A31 DMA controller
The Allwinner A31 has a 16 channels DMA controller that it shares with the
newer A23. Although sharing some similarities with the DMA controller of the
older Allwinner SoCs, it's significantly different, I don't expect it to be
possible to share the driver for these two.

The A31 Controller is able to memory-to-memory or memory-to-device transfers on
the 16 channels in parallel.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2014-07-25 18:14:58 +05:30
Vinod Koul
37a746aaf5 dmaengine: ipu: use return value of request_irq
Commit - 653e67f7e5: "dmaengine: inherit debug settings from the subsystem
for subdirectories" introduced debug option for subdirectories too
This exposed issue with ipu driver not using return value

For now just warn users about it

Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2014-07-25 15:39:50 +05:30
Bjorn Helgaas
e2f9922ad4 dmaengine: jz4740: Fix GPL v2 license string typo
Per license_is_gpl_compatible(), the MODULE_LICENSE() string for GPL v2 is
"GPL v2", not "GPLv2".  Use "GPL v2" so this module doesn't taint the
kernel.

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2014-07-25 14:33:22 +05:30
Jingchang Lu
211bfef7c2 dmaengine: fsl-edma: fix dmamux index calculating error
Signed-off-by: Jingchang Lu <jingchang.lu@freescale.com>
Tested-by: Stefan Agner <stefan@agner.ch>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2014-07-25 14:11:50 +05:30
Nicolin Chen
f892afb07e dmaengine: imx-sdma: Add a new DMATYPE for Shared Peripheral ASRC
Shared Peripheral ASRC, running on SPBA, needs to use shp sciprts for
DMA transfer. So this patch just adds a new DMATYPE for it.

Signed-off-by: Nicolin Chen <nicoleotsuka@gmail.com>
Acked-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2014-07-25 14:10:36 +05:30
Nicolin Chen
0b3518652c dmaengine: imx-sdma: Save imx_dma_data into sdmac
The filter() function is currently called by xlate() while it transfers
imx_dma_data as a local variable to the filter() but releases the data
right after returning a DMA channel pointer, which results chan->private
pointing an invalid memory space.

So this patch just stores the imx_dma_data into sdmac to make usre the
private pointer valid as long as the channel exists.

Signed-off-by: Nicolin Chen <nicoleotsuka@gmail.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2014-07-25 14:10:24 +05:30
Javier Martinez Canillas
b1e51d771f dmaengine: pl330: Check if the DMA descriptor is NULL
Commit 6079d38 ("dmaengine: pl330: Remove useless xfer_cb indirection")
removed the __callback() function which created an unnecessary level of
indirection to execute the tranfer callback .xfer_cb

Unfortunately the commit also changed the semantics slightly since that
function used to check if the request was not NULL before attempting to
execute the callback function. Not checking this could lead to a kernel
NULL pointer dereference error.

Signed-off-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk>
Acked-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2014-07-22 21:38:43 +05:30
Vinod Koul
ff4d02419a Merge commit 'renesas-shdma-for-v3.17' into for-linus 2014-07-21 19:06:28 +05:30
Andy Shevchenko
dd8ecfcac6 dmaengine: dw: don't perform DMA when dmaengine_submit is called
Accordingly to discussion [1] and followed up documentation the DMA controller
driver shouldn't start any DMA operations when dmaengine_submit() is called.

This patch fixes the workflow in dw_dmac driver to follow the documentation.

[1] http://www.spinics.net/lists/arm-kernel/msg125987.html

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2014-07-15 22:14:30 +05:30
Andy Shevchenko
cba15617c3 dmaengine: dw: add debug message to dwc_dostart_first_queued
It would be useful to know when the first descriptor in the queue is started
along with its cookie.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2014-07-15 22:14:29 +05:30
Andy Shevchenko
e7637c6c03 dmaengine: dw: introduce dwc_dostart_first_queued() helper
We have a duplicate code which starts first descriptor in the queue. Let's make
this as a separate helper that can be used in future as well.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2014-07-15 22:14:28 +05:30
Lars-Peter Clausen
c26939e520 dmaengine: pl330: Remove pl330_chan_ctrl()
The pl330_chan_ctrl() function has 3 internal code paths which, except for the
locking, do not share any code outside of their sections. One code path is never
exercised and can be removed. The other two are mostly just forwards to the
_start() and _stop() calls. This patch modifies the code to instead of going via
pl330_chan_ctrl() to call _start() and _stop() directly. This allows to
completely remove pl330_chan_ctrl().

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2014-07-15 22:01:04 +05:30
Lars-Peter Clausen
8ed30a1426 dmaengine: pl330: Simplify marking a request as unused
Instead of storing a special instruction in the command buffer to mark a request
as currently unused just set the descriptor field to NULL.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2014-07-15 22:01:04 +05:30
Lars-Peter Clausen
9dc5a315fe dmaengine: pl330: Embed pl330_req directly into dma_pl330_desc
The pl330_req struct is embedded into the dma_pl330_desc struct. But half of the
pl330_req struct are pointers to other fields of the dma_pl330_desc struct it is
embedded to. By directly embedding the fields from the pl330_req struct into the
dma_pl330_desc struct and reworking the code to work with the dma_pl330_desc
struct those pointers can be eliminated. This slightly simplifies the code.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2014-07-15 22:01:04 +05:30
Lars-Peter Clausen
f6f2421c0a dmaengine: pl330: Merge dma_pl330_dmac and pl330_dmac structs
Both the dma_pl330_dmac and the pl330_dmac struct have the same lifetime and the
separation of them is a relict of this having been two different drivers in the
past. Merging them into one struct makes the code a bit simpler as it for
example allows to remove the pointers going back and forth between the two
structs.

While we are at it also directly embed the pl330_info struct into the
pl330_dmac struct as this allows to remove some more redundant fields.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2014-07-15 22:01:04 +05:30
Lars-Peter Clausen
fbbcd9be96 dmaengine: pl330: Simplify is_manager()
Since we keep a pointer to the manager thread it is fairly easy to check if a
thread is the manager thread.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2014-07-15 22:01:04 +05:30
Lars-Peter Clausen
1b446d2a61 dmaengine: pl330: Remove uneccessary ccr validation
We know that we do not create invalid ccr settings in this driver. There is no
need to validate them.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2014-07-15 22:01:03 +05:30
Lars-Peter Clausen
65ad60600f dmaengine: pl330: Change type pl330_chid from void * to struct pl330_thread *
The pl330_chid field of the dma_pl330_chan struct always holds a pointer to the
thread that is associated with the channel. Changing its type form void * to
struct pl330_thread makes things more type safe and removes the need for
unnecessary typecasts. While we are at it also rename the field from the cryptic
pl330_chid to thread.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2014-07-15 22:01:03 +05:30
Lars-Peter Clausen
6079d38ca2 dmaengine: pl330: Remove useless xfer_cb indirection
The xfer_cb callback of the pl330_req struct is always set to the same function.
This adds an unnecessary step of indirection. Instead just call the callback
function directly.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2014-07-15 22:01:03 +05:30
Lars-Peter Clausen
be025329fd dmaengine: pl330: Remove unused mc_len field from _pl330_req struct
The mc_len is initialized but its value is never read again, so remove it.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2014-07-15 22:01:03 +05:30
Lars-Peter Clausen
d5cef121ff dmaengine: pl330: Remove unused next field form pl330_xfer struct
The next field is always NULL, so we can remove it.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2014-07-15 22:01:03 +05:30
Lars-Peter Clausen
c9392d80ae dmaengine: pl330: Remove unused client_data field form pl330_info
The field is completely unused, remove it.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2014-07-15 22:01:03 +05:30
Lars-Peter Clausen
7ae342fd6f dmaengine: pl330: Remove unused dmac_reset callback
The dmac_reset() callaback of the pl330_info struct is always set to NULL, so
remove it.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2014-07-15 22:01:03 +05:30
Lars-Peter Clausen
fa01ef38d6 dmaengine: pl330: Remove unused pl330_chanstatus struct
The pl330_chanstatus struct is completely unused, so remove it.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2014-07-15 22:01:02 +05:30
Lars-Peter Clausen
f0564c7ecb dmaengine: pl330: Remove duplicated cachecontrol enum
The settings for destination and source cache control are exactly the same. This
patch removes the duplicated enum and uses the same for both destination and
source cache control.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2014-07-15 22:01:02 +05:30
Lars-Peter Clausen
585a9d0b43 dmaengine: pl330: Use dma_transfer_direction instead of custom pl330_reqtype
The pl330 driver has the custom pl330_reqtype enum which has the same possible
settings as the generic dma_transfer_direction enum. Switching over to the
generic enum internally makes it possible to directly initialize it from the
transfer request direction.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2014-07-15 22:01:02 +05:30
Wolfram Sang
653e67f7e5 dmaengine: inherit debug settings from the subsystem for subdirectories
To be able to see debug messages during boot, enable the debug settings
from Kconfig also for drivers in subdirectories.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2014-07-15 21:47:33 +05:30
Geert Uytterhoeven
0cdbee33ea dmaengine: shdma: Use defines instead of hardcoded numbers
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
2014-07-15 18:02:29 +09:00
Joe Perches
9f92d2232d dmaengine: Use dma_zalloc_coherent
Use the zeroing function instead of dma_alloc_coherent & memset(,0,)

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2014-07-14 22:29:35 +05:30
Andy Gross
89751d0a2a dmaengine: qcom_bam_dma: Add descriptor flags
This patch adds support for end of transaction (EOT) and notify when done (NWD)
hardware descriptor flags.

The EOT flag requests that the peripheral assert an end of transaction interrupt
when that descriptor is complete.  It also results in special signaling protocol
that is used between the attached peripheral and the core using the DMA
controller.  Clients will specify DMA_PREP_INTERRUPT to enable this flag.

The NWD flag requests that the peripheral wait until the data has been fully
processed by the peripheral before moving on to the next descriptor.  Clients
will specify DMA_PREP_FENCE to enable this flag.

Signed-off-by: Andy Gross <agross@codeaurora.org>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2014-07-14 22:06:41 +05:30
Hongbo Zhang
43452fadd6 dmaengine: Freescale: change descriptor release process for supporting async_tx
Fix the potential risk when enable config NET_DMA and ASYNC_TX. Async_tx is
lack of support in current release process of dma descriptor, all descriptors
will be released whatever is acked or no-acked by async_tx, so there is a
potential race condition when dma engine is uesd by others clients (e.g. when
enable NET_DMA to offload TCP).

In our case, a race condition which is raised when use both of talitos and
dmaengine to offload xor is because napi scheduler will sync all pending
requests in dma channels, it affects the process of raid operations due to
ack_tx is not checked in fsl dma. The no-acked descriptor is freed which is
submitted just now, as a dependent tx, this freed descriptor trigger
BUG_ON(async_tx_test_ack(depend_tx)) in async_tx_submit().

TASK = ee1a94a0[1390] 'md0_raid5' THREAD: ecf40000 CPU: 0
GPR00: 00000001 ecf41ca0 ee44/921a94a0 0000003f 00000001 c00593e4 00000000 00000001
GPR08: 00000000 a7a7a7a7 00000001 045/920000002 42028042 100a38d4 ed576d98 00000000
GPR16: ed5a11b0 00000000 2b162000 00000200 046/920000000 2d555000 ed3015e8 c15a7aa0
GPR24: 00000000 c155fc40 00000000 ecb63220 ecf41d28 e47/92f640bb0 ef640c30 ecf41ca0
NIP [c02b048c] async_tx_submit+0x6c/0x2b4
LR [c02b068c] async_tx_submit+0x26c/0x2b4
Call Trace:
[ecf41ca0] [c02b068c] async_tx_submit+0x26c/0x2b448/92 (unreliable)
[ecf41cd0] [c02b0a4c] async_memcpy+0x240/0x25c
[ecf41d20] [c0421064] async_copy_data+0xa0/0x17c
[ecf41d70] [c0421cf4] __raid_run_ops+0x874/0xe10
[ecf41df0] [c0426ee4] handle_stripe+0x820/0x25e8
[ecf41e90] [c0429080] raid5d+0x3d4/0x5b4
[ecf41f40] [c04329b8] md_thread+0x138/0x16c
[ecf41f90] [c008277c] kthread+0x8c/0x90
[ecf41ff0] [c0011630] kernel_thread+0x4c/0x68

Another modification in this patch is the change of completed descriptors,
there is a potential risk which caused by exception interrupt, all descriptors
in ld_running list are seemed completed when an interrupt raised, it works fine
under normal condition, but if there is an exception occured, it cannot work as
our excepted. Hardware should not be depend on s/w list, the right way is to
read current descriptor address register to find the last completed descriptor.
If an interrupt is raised by an error, all descriptors in ld_running should not
be seemed finished, or these unfinished descriptors in ld_running will be
released wrongly.

A simple way to reproduce:
Enable dmatest first, then insert some bad descriptors which can trigger
Programming Error interrupts before the good descriptors. Last, the good
descriptors will be freed before they are processsed because of the exception
intrerrupt.

Note: the bad descriptors are only for simulating an exception interrupt.  This
case can illustrate the potential risk in current fsl-dma very well.

Signed-off-by: Hongbo Zhang <hongbo.zhang@freescale.com>
Signed-off-by: Qiang Liu <qiang.liu@freescale.com>
Signed-off-by: Ira W. Snyder <iws@ovro.caltech.edu>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2014-07-14 21:32:18 +05:30
Hongbo Zhang
14c6a3333c dmaengine: Freescale: add suspend resume functions for DMA driver
This patch adds suspend and resume functions for Freescale DMA driver.

Signed-off-by: Hongbo Zhang <hongbo.zhang@freescale.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2014-07-14 21:32:18 +05:30