linux.git/drivers/dma/pl330.c, branch v4.1 Linux kernel source tree dmaengine: pl330: Fix hang on dmaengine_terminate_all on certain boards 2015-05-22T12:31:03+00:00 Krzysztof Kozlowski k.kozlowski@samsung.com 2015-05-21T00:34:09+00:00 81cc6edc08705ac0146fe6ac14a0982a31ce6f3d The pl330 device could hang infinitely on certain boards when DMA channels are terminated. It was caused by lack of runtime resume when executing pl330_terminate_all() which calls the _stop() function. _stop() accesses device register and can loop infinitely while checking for device state. The hang was confirmed by Dinh Nguyen on Altera SOCFPGA Cyclone V board during boot. It can be also triggered with: $ echo 1 > /sys/module/dmatest/parameters/iterations $ echo dma1chan0 > /sys/module/dmatest/parameters/channel $ echo 1 > /sys/module/dmatest/parameters/run $ sleep 1 $ cat /sys/module/dmatest/parameters/run Reported-by: Dinh Nguyen <dinguyen@opensource.altera.com> Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com> Fixes: ae43b3289186 ("ARM: 8202/1: dmaengine: pl330: Add runtime Power Management support v12") Cc: <stable@vger.kernel.org> Tested-by: Dinh Nguyen <dinguyen@opensource.altera.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com> 
The pl330 device could hang infinitely on certain boards when DMA
channels are terminated.

It was caused by lack of runtime resume when executing
pl330_terminate_all() which calls the _stop() function. _stop() accesses
device register and can loop infinitely while checking for device state.

The hang was confirmed by Dinh Nguyen on Altera SOCFPGA Cyclone V
board during boot. It can be also triggered with:

$ echo 1 > /sys/module/dmatest/parameters/iterations
$ echo dma1chan0 > /sys/module/dmatest/parameters/channel
$ echo 1 > /sys/module/dmatest/parameters/run
$ sleep 1
$ cat /sys/module/dmatest/parameters/run

Reported-by: Dinh Nguyen <dinguyen@opensource.altera.com>
Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Fixes: ae43b3289186 ("ARM: 8202/1: dmaengine: pl330: Add runtime Power Management support v12")
Cc: <stable@vger.kernel.org>
Tested-by: Dinh Nguyen <dinguyen@opensource.altera.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
dmaengine: pl330: fix return status on pending transfers 2015-03-18T17:11:49+00:00 Ben Dooks ben.dooks@codethink.co.uk 2015-03-16T11:52:45+00:00 75967b788c2898601620ce91ed14b4a9a371b6fe The pl330_tx_status() function returns the desc->status if the dma_cookie_status() call does indicate the cookie completed, however the desc->status is not look directly compatible. Sparse throws the following warning: pl330.c:2262:35: warning: mixing different enum types pl330.c:2262:35: int enum desc_status versus pl330.c:2262:35: int enum dma_status Attempt to fix this by adding a switch statement to turn the desc->status into a dma_status. Note, this has only been tested with the dmatest suite. Signed-off-by: Ben Dooks <ben.dooks@codethink.co.uk> -- Vinod Koul <vinod.koul@intel.com> Dan Williams <dan.j.williams@intel.com> DMA List <dmaengine@vger.kernel.org> Maxime Ripard <maxime.ripard@free-electrons.com> Jassi Brar <jassisinghbrar@gmail.com> Liviu Dudau <Liviu.Dudau@arm.com> Linux ARM Kernel <linux-arm-kernel@lists.infradead.org> Signed-off-by: Vinod Koul <vinod.koul@intel.com> 
The pl330_tx_status() function returns the desc->status if the
dma_cookie_status() call does indicate the cookie completed,
however the desc->status is not look directly compatible. Sparse
throws the following warning:

pl330.c:2262:35: warning: mixing different enum types
pl330.c:2262:35:     int enum desc_status  versus
pl330.c:2262:35:     int enum dma_status

Attempt to fix this by adding a switch statement to turn the
desc->status into a dma_status.

Note, this has only been tested with the dmatest suite.

Signed-off-by: Ben Dooks <ben.dooks@codethink.co.uk>
--
Vinod Koul <vinod.koul@intel.com>
Dan Williams <dan.j.williams@intel.com>
DMA List <dmaengine@vger.kernel.org>
Maxime Ripard <maxime.ripard@free-electrons.com>
Jassi Brar <jassisinghbrar@gmail.com>
Liviu Dudau <Liviu.Dudau@arm.com>
Linux ARM Kernel <linux-arm-kernel@lists.infradead.org>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
dmaengine: pl330: make unexported functions static 2015-03-18T17:11:49+00:00 Ben Dooks ben.dooks@codethink.co.uk 2015-03-16T11:52:44+00:00 5503aed8117881f58a2688521dfbf9fc7dbcdfe7 Whilst running sparse on pl330 driver it was noticed there are two functions that are not static but not exported to any other users in the kernel. Fix the following warnings by making 'pl330_pause' and the 'pl330_get_current_xferred_count' static: pl330.c:2165:5: warning: symbol 'pl330_pause' was not declared. Should it be static? pl330.c:2206:5: warning: symbol 'pl330_get_current_xferred_count' was not declared. Should it be static? Signed-off-by: Ben Dooks <ben.dooks@codethink.co.uk> -- Vinod Koul <vinod.koul@intel.com> Dan Williams <dan.j.williams@intel.com> DMA List <dmaengine@vger.kernel.org> Maxime Ripard <maxime.ripard@free-electrons.com> Jassi Brar <jassisinghbrar@gmail.com> Liviu Dudau <Liviu.Dudau@arm.com> Linux ARM Kernel <linux-arm-kernel@lists.infradead.org> Signed-off-by: Vinod Koul <vinod.koul@intel.com> 
Whilst running sparse on pl330 driver it was noticed there are
two functions that are not static but not exported to any other
users in the kernel.

Fix the following warnings by making 'pl330_pause' and the
'pl330_get_current_xferred_count' static:

pl330.c:2165:5: warning: symbol 'pl330_pause' was not declared. Should it be static?
pl330.c:2206:5: warning: symbol 'pl330_get_current_xferred_count' was not declared. Should it be static?

Signed-off-by: Ben Dooks <ben.dooks@codethink.co.uk>
--
Vinod Koul <vinod.koul@intel.com>
Dan Williams <dan.j.williams@intel.com>
DMA List <dmaengine@vger.kernel.org>
Maxime Ripard <maxime.ripard@free-electrons.com>
Jassi Brar <jassisinghbrar@gmail.com>
Liviu Dudau <Liviu.Dudau@arm.com>
Linux ARM Kernel <linux-arm-kernel@lists.infradead.org>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
dmaengine: pl330: fix issues with big-endian armv7 2015-03-18T17:11:48+00:00 Ben Dooks ben.dooks@codethink.co.uk 2015-03-16T11:52:43+00:00 3a2307f72e684199a27ae9d8e7cfd98e8b05c8db When running Xilinx Zynq in big-endian mode the pl330 driver fails to pass the dmatest suite. To fix this, ensure all non byte values are written in little endian. As a note, the documentation does not mention if it will do big-endian descriptor fetches, only that it will swap the data in flight. Signed-off-by: Ben Dooks <ben.dooks@codethink.co.uk> -- Vinod Koul <vinod.koul@intel.com> Dan Williams <dan.j.williams@intel.com> DMA List <dmaengine@vger.kernel.org> Maxime Ripard <maxime.ripard@free-electrons.com> Jassi Brar <jassisinghbrar@gmail.com> Liviu Dudau <Liviu.Dudau@arm.com> Linux ARM Kernel <linux-arm-kernel@lists.infradead.org> Signed-off-by: Vinod Koul <vinod.koul@intel.com> 
When running Xilinx Zynq in big-endian mode the pl330 driver
fails to pass the dmatest suite. To fix this, ensure all non
byte values are written in little endian.

As a note, the documentation does not mention if it will do
big-endian descriptor fetches, only that it will swap the
data in flight.

Signed-off-by: Ben Dooks <ben.dooks@codethink.co.uk>
--
Vinod Koul <vinod.koul@intel.com>
Dan Williams <dan.j.williams@intel.com>
DMA List <dmaengine@vger.kernel.org>
Maxime Ripard <maxime.ripard@free-electrons.com>
Jassi Brar <jassisinghbrar@gmail.com>
Liviu Dudau <Liviu.Dudau@arm.com>
Linux ARM Kernel <linux-arm-kernel@lists.infradead.org>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
dmaengine: pl330: add DMA_PAUSE feature 2015-02-16T04:03:36+00:00 Robert Baldyga r.baldyga@samsung.com 2015-02-11T12:23:18+00:00 88987d2c7534a0269f567fb101e6d71a08f0f01d DMA_PAUSE command is used for halting DMA transfer on chosen channel. It can be useful when we want to safely read residue before terminating all requests on channel. Otherwise there can be situation when some data is transferred before channel termination but after reading residue, which obviously results with data loss. To avoid this situation we can pause channel, read residue and then terminate all requests. This scenario is common, for example, in serial port drivers. Signed-off-by: Robert Baldyga <r.baldyga@samsung.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com> 
DMA_PAUSE command is used for halting DMA transfer on chosen channel.
It can be useful when we want to safely read residue before terminating
all requests on channel. Otherwise there can be situation when some data
is transferred before channel termination but after reading residue,
which obviously results with data loss. To avoid this situation we can
pause channel, read residue and then terminate all requests.
This scenario is common, for example, in serial port drivers.

Signed-off-by: Robert Baldyga <r.baldyga@samsung.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
dmaengine: pl330: improve pl330_tx_status() function 2015-02-16T04:03:35+00:00 Robert Baldyga r.baldyga@samsung.com 2015-02-11T12:23:17+00:00 aee4d1fac887252faf6f7caf7bf1616131d5dbcd This patch adds possibility to read residue of DMA transfer. It's useful when we want to know how many bytes have been transferred before we terminate channel. It can take place, for example, on timeout interrupt. Signed-off-by: Lukasz Czerwinski <l.czerwinski@samsung.com> Signed-off-by: Robert Baldyga <r.baldyga@samsung.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com> 
This patch adds possibility to read residue of DMA transfer. It's useful
when we want to know how many bytes have been transferred before we
terminate channel. It can take place, for example, on timeout interrupt.

Signed-off-by: Lukasz Czerwinski <l.czerwinski@samsung.com>
Signed-off-by: Robert Baldyga <r.baldyga@samsung.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
dmaengine: pl330: fix bug that cause start the same descs in cyclic 2015-02-11T00:20:19+00:00 Addy Ke addy.ke@rock-chips.com 2014-12-08T11:28:20+00:00 0091b9d6c1ef2caab6cb3b6c0aa75f9948307856 This bug will cause NULL pointer after commit dfac17, and cause wrong package in I2S DMA transfer before commit dfac17. Tested on RK3288-pinky2 board. Detail: I2S DMA transfer(sound/core/pcm_dmaengine.c): dmaengine_pcm_prepare_and_submit --> dmaengine_prep_dma_cyclic --> pl330_prep_dma_cyclic --> the case: 1. pl330_submit_req(desc0): thrd->req[0].desc = desc0, thrd->lstenq = 0 2. pl330_submit_req(desc1): thrd->req[1].desc = desc1, thrd->lstenq = 1 3. _start(desc0) by submit_req: thrd->req_running = 0 because: idx = 1 - thrd->lstenq = 0 4. pl330_update(desc0 OK): thrd->req[0].desc = NULL, desc0 to req_done list because: idx = active = thrd->req_running = 0 5. _start(desc1) by pl330_update: thrd->req_running = 1 because: idx = 1 - thrd->lstenq = 0, but thrd->req[0].desc == NULL, so: idx = thrd->lstenq = 1 6. pl330_submit_req(desc2): thrd->req[0].desc = desc2, thrd->lstenq = 0 7. _start(desc1) by submit_req: thrd->req_running = 1 because: idx = 1 - thrd->lstenq = 1 Note: _start started the same descs _start should start desc2 here, NOT desc1 8. pl330_update(desc1 OK): thrd->req[1].desc = NULL, desc1 to req_done list because: idx = active = thrd->req_running = 1 9. _start(desc2) by pl330_update : thrd->req_running = 0 because: idx = 1 - thrd->lstenq = 0 10.pl330_update(desc1 OK, NOT desc2): thrd->req[0].desc = NULL, desc2 to req_done list because: idx = active = thrd->req_running = 0 11.pl330_submit_req(desc3): thrd->req[0].desc = desc3, thrd->lstenq = 0 12.pl330_submit_req(desc4): thrd->req[1].desc = desc4, thrd->lstenq = 1 13._start(desc3) by submit_req: thrd->req_running = 0 because: idx = 1 - thrd->lstenq = 0 14.pl330_update(desc2 OK NOT desc3): thrd->req[0].desc = NULL desc3 to req_done list because: idx = active = thrd->req_running = 0 15._start(desc4) by pl330_update: thrd->req_running = 1 because: idx = 1 - thrd->lstenq = 0, but thrd->req[0].desc == NULL, so: idx = thrd->lstenq = 1 16.pl330_submit_req(desc5): thrd->req[0].desc = desc5, thrd->lstenq = 0 17._start(desc4) by submit_req: thrd->req_running = 1 because: idx = 1 - thrd->lstenq = 1 18.pl330_update(desc3 OK NOT desc4): thrd->req[1].desc = NULL desc4 to req_done list because: idx = active = thrd->req_running = 1 19._start(desc4) by pl330_update: thrd->req_running = 0 because: idx = 1 - thrd->lstenq = 1, but thrd->req[1].desc == NULL, so: idx = thrd->lstenq = 0 20.pl330_update(desc4 OK): thrd->req[0].desc = NULL, desc5 to req_done list because: idx = active = thrd->req_running = 0 21.pl330_update(desc4 OK): 1) before commit dfac17(set req_running -1 in pl330_update/mark_free()): because: active = -1, abort result: desc0-desc5's callback are all called, but step 10 and step 18 go wrong. 2) before commit dfac17: idx = active = thrd->req_runnig = 0 --> descdone = thrd->req[0] = NULL --> list_add_tail(&descdone->rqd, &pl330->req_done); --> got NULL pointer!!! Signed-off-by: Addy Ke <addy.ke@rock-chips.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com> 
This bug will cause NULL pointer after commit dfac17, and cause
wrong package in I2S DMA transfer before commit dfac17.

Tested on RK3288-pinky2 board.

Detail:
I2S DMA transfer(sound/core/pcm_dmaengine.c):
dmaengine_pcm_prepare_and_submit -->
dmaengine_prep_dma_cyclic -->
pl330_prep_dma_cyclic -->
the case:
1. pl330_submit_req(desc0): thrd->req[0].desc = desc0, thrd->lstenq = 0
2. pl330_submit_req(desc1): thrd->req[1].desc = desc1, thrd->lstenq = 1
3. _start(desc0) by submit_req: thrd->req_running = 0
   because: idx = 1 - thrd->lstenq = 0
4. pl330_update(desc0 OK): thrd->req[0].desc = NULL, desc0 to req_done list
   because: idx = active = thrd->req_running = 0
5. _start(desc1) by pl330_update: thrd->req_running = 1
   because:
   idx = 1 - thrd->lstenq = 0, but thrd->req[0].desc == NULL,
   so:
   idx = thrd->lstenq = 1
6. pl330_submit_req(desc2): thrd->req[0].desc = desc2, thrd->lstenq = 0
7. _start(desc1) by submit_req: thrd->req_running = 1
   because: idx = 1 - thrd->lstenq = 1
   Note: _start started the same descs
         _start should start desc2 here, NOT desc1

8. pl330_update(desc1 OK): thrd->req[1].desc = NULL, desc1 to req_done list
   because: idx = active = thrd->req_running = 1
9. _start(desc2) by pl330_update : thrd->req_running = 0
   because: idx = 1 - thrd->lstenq = 0
10.pl330_update(desc1 OK, NOT desc2): thrd->req[0].desc = NULL,
   desc2 to req_done list
   because: idx = active = thrd->req_running = 0

11.pl330_submit_req(desc3): thrd->req[0].desc = desc3, thrd->lstenq = 0
12.pl330_submit_req(desc4): thrd->req[1].desc = desc4, thrd->lstenq = 1
13._start(desc3) by submit_req: thrd->req_running = 0
   because: idx = 1 - thrd->lstenq = 0
14.pl330_update(desc2 OK NOT desc3): thrd->req[0].desc = NULL
   desc3 to req_done list
   because: idx = active = thrd->req_running = 0
15._start(desc4) by pl330_update: thrd->req_running = 1
   because:
   idx = 1 - thrd->lstenq = 0, but thrd->req[0].desc == NULL,
   so:
   idx = thrd->lstenq = 1
16.pl330_submit_req(desc5): thrd->req[0].desc = desc5, thrd->lstenq = 0
17._start(desc4) by submit_req: thrd->req_running = 1
   because: idx = 1 - thrd->lstenq = 1
18.pl330_update(desc3 OK NOT desc4): thrd->req[1].desc = NULL
   desc4 to req_done list
   because: idx = active = thrd->req_running = 1
19._start(desc4) by pl330_update: thrd->req_running = 0
   because:
   idx = 1 - thrd->lstenq = 1, but thrd->req[1].desc == NULL,
   so:
   idx = thrd->lstenq = 0
20.pl330_update(desc4 OK): thrd->req[0].desc = NULL, desc5 to req_done list
   because: idx = active = thrd->req_running = 0
21.pl330_update(desc4 OK):
   1) before commit dfac17(set req_running -1 in pl330_update/mark_free()):
      because: active = -1, abort
      result: desc0-desc5's callback are all called,
	      but step 10 and step 18 go wrong.
   2) before commit dfac17:
      idx = active = thrd->req_runnig = 0 -->
      descdone = thrd->req[0] = NULL -->
      list_add_tail(&descdone->rqd, &pl330->req_done); -->
      got NULL pointer!!!

Signed-off-by: Addy Ke <addy.ke@rock-chips.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
dmaengine: pl330: Declare slave capabilities for the generic code 2014-12-22T07:04:21+00:00 Maxime Ripard maxime.ripard@free-electrons.com 2014-11-17T13:42:50+00:00 dcabe456b4d4d04606268036d8ca5ce84aa84037 Now that the generic slave caps code can make use of the device assigned capabilities, instead of relying on a callback to be implemented. Make use of this code. Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com> 
Now that the generic slave caps code can make use of the device assigned
capabilities, instead of relying on a callback to be implemented.

Make use of this code.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
dmaengine: pl330: Split device_control 2014-12-22T07:02:15+00:00 Maxime Ripard maxime.ripard@free-electrons.com 2014-11-17T13:42:29+00:00 740aa95703c59d8b59adb78c65efa08714f66ebb Split the device_control callback of the AMBA PL330 DMA driver to make use of the newly introduced callbacks, that will eventually be used to retrieve slave capabilities. Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com> 
Split the device_control callback of the AMBA PL330 DMA driver to make use
of the newly introduced callbacks, that will eventually be used to retrieve
slave capabilities.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
dmaengine: Make the destination abbreviation coherent 2014-12-22T06:58:55+00:00 Maxime Ripard maxime.ripard@free-electrons.com 2014-11-17T13:41:57+00:00 ceacbdbf65c4cf48a130db6152c6e03432c85ed1 The dmaengine header abbreviates destination as at least two different strings. Make a coherent use of a single one. Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com> Acked-by: Mark Brown <broonie@kernel.org> Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Acked-by: Stephen Warren <swarren@wwwdotorg.org> Signed-off-by: Vinod Koul <vinod.koul@intel.com> 
The dmaengine header abbreviates destination as at least two different strings.
Make a coherent use of a single one.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Acked-by: Mark Brown <broonie@kernel.org>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Stephen Warren <swarren@wwwdotorg.org>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>