user/sven/linux.git/drivers/dma/cppi41.c, branch v4.9.145

dmaengine: cppi41: delete channel from pending list when stop channel

2018-12-13T08:20:29Z

commit 59861547ec9a9736e7882f6fb0c096a720ff811a upstream. The driver defines three states for a cppi channel. - idle: .chan_busy == 0 && not in .pending list - pending: .chan_busy == 0 && in .pending list - busy: .chan_busy == 1 && not in .pending list There are cases in which the cppi channel could be in the pending state when cppi41_dma_issue_pending() is called after cppi41_runtime_suspend() is called. cppi41_stop_chan() has a bug for these cases to set channels to idle state. It only checks the .chan_busy flag, but not the .pending list, then later when cppi41_runtime_resume() is called the channels in .pending list will be transitioned to busy state. Removing channels from the .pending list solves the problem. Fixes: 975faaeb9985 ("dma: cppi41: start tear down only if channel is busy") Cc: stable@vger.kernel.org # v3.15+ Signed-off-by: Bin Liu Reviewed-by: Peter Ujfalusi Signed-off-by: Vinod Koul Signed-off-by: Greg Kroah-Hartman

dmaengine: cppi41: Fix oops in cppi41_runtime_resume

2017-02-09T07:08:29Z

commit 362f4562466c3b9490e733e06999025638310d4a upstream. Commit fdea2d09b997 ("dmaengine: cppi41: Add basic PM runtime support") together with recent MUSB changes allowed USB and DMA on BeagleBone to idle when no cable is connected. But looks like few corner case issues still remain. Looks like just by re-plugging USB cable about ten or so times on BeagleBone when configured in USB peripheral mode we can get warnings and eventually trigger an oops in cppi41 DMA: WARNING: CPU: 0 PID: 14 at drivers/dma/cppi41.c:1154 cppi41_runtime_suspend+ x28/0x38 [cppi41] ... WARNING: CPU: 0 PID: 14 at drivers/dma/cppi41.c:452 push_desc_queue+0x94/0x9c [cppi41] ... Unable to handle kernel NULL pointer dereference at virtual address 00000104 pgd = c0004000 [00000104] *pgd=00000000 Internal error: Oops: 805 [#1] SMP ARM ... [] (cppi41_runtime_resume [cppi41]) from [] (__rpm_callback+0xc0/0x214) [] (__rpm_callback) from [] (rpm_callback+0x20/0x80) [] (rpm_callback) from [] (rpm_resume+0x504/0x78c) [] (rpm_resume) from [] (pm_runtime_work+0x60/0xa8) [] (pm_runtime_work) from [] (process_one_work+0x2b4/0x808) This is because of a race with runtime PM and cppi41_dma_issue_pending() as reported by Alexandre Bailon in earlier set of patches. Based on mailing list discussions we however came to the conclusion that a different fix from Alexandre's fix is needed in order to guarantee that DMA is really active when we try to use it. To fix the issue, we need to add a driver specific flag as we otherwise can have -EINPROGRESS state set by runtime PM and can't rely on pm_runtime_active() to tell us when we can use the DMA. And we need to make sure the DMA transfers get triggered in the queued order. So let's always queue the transfers, then flush the queue from both cppi41_dma_issue_pending() and cppi41_runtime_resume() as suggested by Grygorii Strashko in an earlier example patch. For reference, this is also documented in Documentation/power/runtime_pm.txt in the example at the end of the file as pointed out by Grygorii Strashko . Based on earlier patches from Alexandre Bailon and Grygorii Strashko modified based on testing and what was discussed on the mailing lists. Fixes: fdea2d09b997 ("dmaengine: cppi41: Add basic PM runtime support") Cc: Andy Shevchenko Cc: Bin Liu Cc: Grygorii Strashko Cc: Kevin Hilman Cc: Patrick Titiano Cc: Sergei Shtylyov Reported-by: Alexandre Bailon Signed-off-by: Tony Lindgren Tested-by: Bin Liu Signed-off-by: Vinod Koul Signed-off-by: Greg Kroah-Hartman

dmaengine: cppi41: Fix runtime PM timeouts with USB mass storage

2017-02-09T07:08:29Z

commit ae4a3e028bb8b59e7cfeb0cc9ef03d885182ce8b upstream. Commit fdea2d09b997 ("dmaengine: cppi41: Add basic PM runtime support") added runtime PM support for cppi41, but had corner case issues. Some of the issues were fixed with commit 098de42ad670 ("dmaengine: cppi41: Fix unpaired pm runtime when only a USB hub is connected"). That fix however caused a new regression where we can get error -115 messages with USB on BeagleBone when connecting a USB mass storage device to a hub. This is because when connecting a USB mass storage device to a hub, the initial DMA transfers can take over 200ms to complete and cppi41 autosuspend delay times out. To fix the issue, we want to implement refcounting for chan_busy array that contains the active dma transfers. Increasing the autosuspend delay won't help as that the delay could be potentially seconds, and it's best to let the USB subsystem to deal with the timeouts on errors. The earlier attempt for runtime PM was buggy as the pm_runtime_get/put() calls could get unpaired easily as they did not follow the state of the chan_busy array as described in commit 098de42ad670 ("dmaengine: cppi41: Fix unpaired pm runtime when only a USB hub is connected". Let's fix the issue by adding pm_runtime_get() to where a new transfer is added to the chan_busy array, and calls to pm_runtime_put() where chan_busy array entry is cleared. This prevents any autosuspend timeouts from happening while dma transfers are active. Fixes: 098de42ad670 ("dmaengine: cppi41: Fix unpaired pm runtime when only a USB hub is connected") Fixes: fdea2d09b997 ("dmaengine: cppi41: Add basic PM runtime support") Cc: Andy Shevchenko Cc: Bin Liu Cc: Grygorii Strashko Cc: Kevin Hilman Cc: Patrick Titiano Cc: Sergei Shtylyov Signed-off-by: Tony Lindgren Tested-by: Bin Liu Signed-off-by: Vinod Koul Signed-off-by: Greg Kroah-Hartman

dmaengine: cppi41: More PM runtime fixes

2016-11-17T10:39:23Z

Fix use of u32 instead of int for checking for negative errors values as pointed out by Dan Carpenter . And while testing the PM runtime error path by randomly returning failed values in runtime resume, I noticed two more places that need fixing: - If pm_runtime_get_sync() fails in probe, we still need to do pm_runtime_put_sync() to keep the use count happy. We could call pm_runtime_put_noidle() on the error path, but we're just going to call pm_runtime_disable() after that so pm_runtime_put_sync() will do what we want - We should print an error if pm_runtime_get_sync() fails in cppi41_dma_alloc_chan_resources() so we know where it happens Reported-by: Dan Carpenter Fixes: 740b4be3f742 ("dmaengine: cpp41: Fix handling of error path") Signed-off-by: Tony Lindgren Signed-off-by: Vinod Koul

dmaengine: cpp41: Fix handling of error path

2016-11-14T08:30:16Z

If we return early on pm_runtime_get() error, we need to also call pm_runtime_put_noidle() as pointed out in a musb related thread by Johan Hovold . This is to keep the PM runtime use counts happy. Fixes: fdea2d09b997 ("dmaengine: cppi41: Add basic PM runtime support") Cc: Johan Hovold Signed-off-by: Tony Lindgren Signed-off-by: Vinod Koul

dmaengine: cppi41: Fix unpaired pm runtime when only a USB hub is connected

2016-11-14T05:27:32Z

On am335x with musb host we can end up with unpaired pm runtime calls if a hub with no devices is connected and disconnected. This is because of the conditional pm runtime calls which are always a bad idea. Let's fix the issue by making them unconditional and paired in each function. Fixes: fdea2d09b997 ("dmaengine: cppi41: Add basic PM runtime support") Signed-off-by: Tony Lindgren Signed-off-by: Vinod Koul

dmaengine: cppi41: Fix list not empty warning on module removal

2016-11-14T05:27:21Z

If musb controller is configured with USB peripherals and we have enumerated with a USB host, we can get warnings on removal of the modules: WARNING: CPU: 0 PID: 1269 at drivers/dma/cppi41.c:391 cppi41_dma_free_chan_resources Fix the issue by adding the missing pm_runtime_get to cppi41_dma_free_chan_resources to make sure the pending work list is cleared on removal. Fixes: fdea2d09b997 ("dmaengine: cppi41: Add basic PM runtime support") Signed-off-by: Tony Lindgren Signed-off-by: Vinod Koul

Merge branch 'topic/err_reporting' into for-linus

2016-10-03T03:47:33Z

Signed-off-by: Vinod Koul Conflicts: drivers/dma/cppi41.c

dmaengine: cppi41: Ignore EINPROGRESS for PM runtime

2016-09-14T13:43:22Z

We can occasionally get -EINPROGRESS for pm_runtime_get. In that case we can just continue as we're queueing transfers anyways when pm_runtime_active is not set. Fixes: fdea2d09b997 ("dmaengine: cppi41: Add basic PM runtime support") Signed-off-by: Tony Lindgren Signed-off-by: Vinod Koul

dmaengine: cppi41: mark PM functions as __maybe_unused

2016-09-07T08:08:57Z

When CONFIG_PM_SLEEP is disabled, we get a build error in the cppi41 dmaengine driver, since the runtime-pm functions are hidden within the wrong #ifdef: drivers/dma/cppi41.c:1158:21: error: 'cppi41_runtime_suspend' undeclared here (not in a function) This removes the #ifdef and instead uses __maybe_unused annotations that cannot have this problem. Signed-off-by: Arnd Bergmann Fixes: fdea2d09b997 ("dmaengine: cppi41: Add basic PM runtime support") Signed-off-by: Vinod Koul