linux/drivers/dma/cppi41.c

1223 lines
29 KiB

dmaengine: cppi41: Fix oops in cppi41_runtime_resume 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 ... [<bf0d92cc>] (cppi41_runtime_resume [cppi41]) from [<c0589838>] (__rpm_callback+0xc0/0x214) [<c0589838>] (__rpm_callback) from [<c05899ac>] (rpm_callback+0x20/0x80) [<c05899ac>] (rpm_callback) from [<c0589460>] (rpm_resume+0x504/0x78c) [<c0589460>] (rpm_resume) from [<c058a1a0>] (pm_runtime_work+0x60/0xa8) [<c058a1a0>] (pm_runtime_work) from [<c0156120>] (process_one_work+0x2b4/0x808) This is because of a race with runtime PM and cppi41_dma_issue_pending() as reported by Alexandre Bailon <abailon@baylibre.com> 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 <grygorii.strashko@ti.com> 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 <grygorii.strashko@ti.com>. Based on earlier patches from Alexandre Bailon <abailon@baylibre.com> and Grygorii Strashko <grygorii.strashko@ti.com> modified based on testing and what was discussed on the mailing lists. Fixes: fdea2d09b997 ("dmaengine: cppi41: Add basic PM runtime support") Cc: Andy Shevchenko <andy.shevchenko@gmail.com> Cc: Bin Liu <b-liu@ti.com> Cc: Grygorii Strashko <grygorii.strashko@ti.com> Cc: Kevin Hilman <khilman@baylibre.com> Cc: Patrick Titiano <ptitiano@baylibre.com> Cc: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com> Reported-by: Alexandre Bailon <abailon@baylibre.com> Signed-off-by: Tony Lindgren <tony@atomide.com> Tested-by: Bin Liu <b-liu@ti.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2017-01-19 08:49:08 -08:00
dmaengine: cppi41: Fix runtime PM timeouts with USB mass storage 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 <andy.shevchenko@gmail.com> Cc: Bin Liu <b-liu@ti.com> Cc: Grygorii Strashko <grygorii.strashko@ti.com> Cc: Kevin Hilman <khilman@baylibre.com> Cc: Patrick Titiano <ptitiano@baylibre.com> Cc: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com> Signed-off-by: Tony Lindgren <tony@atomide.com> Tested-by: Bin Liu <b-liu@ti.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2017-01-19 08:49:07 -08:00
dmaengine: cppi41: Fix runtime PM timeouts with USB mass storage 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 <andy.shevchenko@gmail.com> Cc: Bin Liu <b-liu@ti.com> Cc: Grygorii Strashko <grygorii.strashko@ti.com> Cc: Kevin Hilman <khilman@baylibre.com> Cc: Patrick Titiano <ptitiano@baylibre.com> Cc: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com> Signed-off-by: Tony Lindgren <tony@atomide.com> Tested-by: Bin Liu <b-liu@ti.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2017-01-19 08:49:07 -08:00
dmaengine: cppi41: Fix oops in cppi41_runtime_resume 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 ... [<bf0d92cc>] (cppi41_runtime_resume [cppi41]) from [<c0589838>] (__rpm_callback+0xc0/0x214) [<c0589838>] (__rpm_callback) from [<c05899ac>] (rpm_callback+0x20/0x80) [<c05899ac>] (rpm_callback) from [<c0589460>] (rpm_resume+0x504/0x78c) [<c0589460>] (rpm_resume) from [<c058a1a0>] (pm_runtime_work+0x60/0xa8) [<c058a1a0>] (pm_runtime_work) from [<c0156120>] (process_one_work+0x2b4/0x808) This is because of a race with runtime PM and cppi41_dma_issue_pending() as reported by Alexandre Bailon <abailon@baylibre.com> 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 <grygorii.strashko@ti.com> 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 <grygorii.strashko@ti.com>. Based on earlier patches from Alexandre Bailon <abailon@baylibre.com> and Grygorii Strashko <grygorii.strashko@ti.com> modified based on testing and what was discussed on the mailing lists. Fixes: fdea2d09b997 ("dmaengine: cppi41: Add basic PM runtime support") Cc: Andy Shevchenko <andy.shevchenko@gmail.com> Cc: Bin Liu <b-liu@ti.com> Cc: Grygorii Strashko <grygorii.strashko@ti.com> Cc: Kevin Hilman <khilman@baylibre.com> Cc: Patrick Titiano <ptitiano@baylibre.com> Cc: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com> Reported-by: Alexandre Bailon <abailon@baylibre.com> Signed-off-by: Tony Lindgren <tony@atomide.com> Tested-by: Bin Liu <b-liu@ti.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2017-01-19 08:49:08 -08:00
dmaengine: cppi41: Fix oops in cppi41_runtime_resume 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 ... [<bf0d92cc>] (cppi41_runtime_resume [cppi41]) from [<c0589838>] (__rpm_callback+0xc0/0x214) [<c0589838>] (__rpm_callback) from [<c05899ac>] (rpm_callback+0x20/0x80) [<c05899ac>] (rpm_callback) from [<c0589460>] (rpm_resume+0x504/0x78c) [<c0589460>] (rpm_resume) from [<c058a1a0>] (pm_runtime_work+0x60/0xa8) [<c058a1a0>] (pm_runtime_work) from [<c0156120>] (process_one_work+0x2b4/0x808) This is because of a race with runtime PM and cppi41_dma_issue_pending() as reported by Alexandre Bailon <abailon@baylibre.com> 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 <grygorii.strashko@ti.com> 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 <grygorii.strashko@ti.com>. Based on earlier patches from Alexandre Bailon <abailon@baylibre.com> and Grygorii Strashko <grygorii.strashko@ti.com> modified based on testing and what was discussed on the mailing lists. Fixes: fdea2d09b997 ("dmaengine: cppi41: Add basic PM runtime support") Cc: Andy Shevchenko <andy.shevchenko@gmail.com> Cc: Bin Liu <b-liu@ti.com> Cc: Grygorii Strashko <grygorii.strashko@ti.com> Cc: Kevin Hilman <khilman@baylibre.com> Cc: Patrick Titiano <ptitiano@baylibre.com> Cc: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com> Reported-by: Alexandre Bailon <abailon@baylibre.com> Signed-off-by: Tony Lindgren <tony@atomide.com> Tested-by: Bin Liu <b-liu@ti.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2017-01-19 08:49:08 -08:00
dmaengine: cppi41: Fix oops in cppi41_runtime_resume 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 ... [<bf0d92cc>] (cppi41_runtime_resume [cppi41]) from [<c0589838>] (__rpm_callback+0xc0/0x214) [<c0589838>] (__rpm_callback) from [<c05899ac>] (rpm_callback+0x20/0x80) [<c05899ac>] (rpm_callback) from [<c0589460>] (rpm_resume+0x504/0x78c) [<c0589460>] (rpm_resume) from [<c058a1a0>] (pm_runtime_work+0x60/0xa8) [<c058a1a0>] (pm_runtime_work) from [<c0156120>] (process_one_work+0x2b4/0x808) This is because of a race with runtime PM and cppi41_dma_issue_pending() as reported by Alexandre Bailon <abailon@baylibre.com> 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 <grygorii.strashko@ti.com> 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 <grygorii.strashko@ti.com>. Based on earlier patches from Alexandre Bailon <abailon@baylibre.com> and Grygorii Strashko <grygorii.strashko@ti.com> modified based on testing and what was discussed on the mailing lists. Fixes: fdea2d09b997 ("dmaengine: cppi41: Add basic PM runtime support") Cc: Andy Shevchenko <andy.shevchenko@gmail.com> Cc: Bin Liu <b-liu@ti.com> Cc: Grygorii Strashko <grygorii.strashko@ti.com> Cc: Kevin Hilman <khilman@baylibre.com> Cc: Patrick Titiano <ptitiano@baylibre.com> Cc: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com> Reported-by: Alexandre Bailon <abailon@baylibre.com> Signed-off-by: Tony Lindgren <tony@atomide.com> Tested-by: Bin Liu <b-liu@ti.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2017-01-19 08:49:08 -08:00
dmaengine: cppi41: Fix oops in cppi41_runtime_resume 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 ... [<bf0d92cc>] (cppi41_runtime_resume [cppi41]) from [<c0589838>] (__rpm_callback+0xc0/0x214) [<c0589838>] (__rpm_callback) from [<c05899ac>] (rpm_callback+0x20/0x80) [<c05899ac>] (rpm_callback) from [<c0589460>] (rpm_resume+0x504/0x78c) [<c0589460>] (rpm_resume) from [<c058a1a0>] (pm_runtime_work+0x60/0xa8) [<c058a1a0>] (pm_runtime_work) from [<c0156120>] (process_one_work+0x2b4/0x808) This is because of a race with runtime PM and cppi41_dma_issue_pending() as reported by Alexandre Bailon <abailon@baylibre.com> 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 <grygorii.strashko@ti.com> 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 <grygorii.strashko@ti.com>. Based on earlier patches from Alexandre Bailon <abailon@baylibre.com> and Grygorii Strashko <grygorii.strashko@ti.com> modified based on testing and what was discussed on the mailing lists. Fixes: fdea2d09b997 ("dmaengine: cppi41: Add basic PM runtime support") Cc: Andy Shevchenko <andy.shevchenko@gmail.com> Cc: Bin Liu <b-liu@ti.com> Cc: Grygorii Strashko <grygorii.strashko@ti.com> Cc: Kevin Hilman <khilman@baylibre.com> Cc: Patrick Titiano <ptitiano@baylibre.com> Cc: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com> Reported-by: Alexandre Bailon <abailon@baylibre.com> Signed-off-by: Tony Lindgren <tony@atomide.com> Tested-by: Bin Liu <b-liu@ti.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2017-01-19 08:49:08 -08:00
dmaengine: cppi41: Fix oops in cppi41_runtime_resume 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 ... [<bf0d92cc>] (cppi41_runtime_resume [cppi41]) from [<c0589838>] (__rpm_callback+0xc0/0x214) [<c0589838>] (__rpm_callback) from [<c05899ac>] (rpm_callback+0x20/0x80) [<c05899ac>] (rpm_callback) from [<c0589460>] (rpm_resume+0x504/0x78c) [<c0589460>] (rpm_resume) from [<c058a1a0>] (pm_runtime_work+0x60/0xa8) [<c058a1a0>] (pm_runtime_work) from [<c0156120>] (process_one_work+0x2b4/0x808) This is because of a race with runtime PM and cppi41_dma_issue_pending() as reported by Alexandre Bailon <abailon@baylibre.com> 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 <grygorii.strashko@ti.com> 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 <grygorii.strashko@ti.com>. Based on earlier patches from Alexandre Bailon <abailon@baylibre.com> and Grygorii Strashko <grygorii.strashko@ti.com> modified based on testing and what was discussed on the mailing lists. Fixes: fdea2d09b997 ("dmaengine: cppi41: Add basic PM runtime support") Cc: Andy Shevchenko <andy.shevchenko@gmail.com> Cc: Bin Liu <b-liu@ti.com> Cc: Grygorii Strashko <grygorii.strashko@ti.com> Cc: Kevin Hilman <khilman@baylibre.com> Cc: Patrick Titiano <ptitiano@baylibre.com> Cc: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com> Reported-by: Alexandre Bailon <abailon@baylibre.com> Signed-off-by: Tony Lindgren <tony@atomide.com> Tested-by: Bin Liu <b-liu@ti.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2017-01-19 08:49:08 -08:00
dma: cppi41: wait longer for the HW to return the descriptor For a "complete" teardown we have to wait until the teardown descriptor is returned by the hardware. The g_zero testcase "testusb -a -t 9" triggers the following warning quite reliable: |------------[ cut here ]------------ |WARNING: CPU: 0 PID: 0 at drivers/dma/cppi41.c:609 cppi41_dma_control+0x198/0x304() |[<c003f84c>] (warn_slowpath_null) from [<c02be8d8>] |[<c02be8d8>] (cppi41_dma_control) from [<bf08d25c>] |[<bf08d25c>] (cppi41_dma_channel_abort [musb_hdrc]) |[<bf08bc38>] (nuke.constprop.10 [musb_hdrc]) |[<bf08bd08>] (musb_gadget_disable [musb_hdrc]) |[<bf252524>] (disable_endpoints [usb_f_ss_lb]) |[<bf2525d8>] (disable_source_sink [usb_f_ss_lb]) |[<bf25260c>] (sourcesink_set_alt [usb_f_ss_lb]) |[<bf23ad24>] (composite_setup [libcomposite]) |[<bf08a2f4>] (musb_g_ep0_irq [musb_hdrc]) |[<bf085ec4>] (musb_interrupt [musb_hdrc]) |[<bf0aeaf4>] (dsps_interrupt [musb_dsps]) |[<c0080ea8>] (handle_irq_event_percpu) |[<c008112c>] (handle_irq_event) |[<c008348c>] (handle_level_irq) |[<c00807a8>] (generic_handle_irq) |[<c000ee80>] (handle_IRQ) |[<c00085f0>] (omap3_intc_handle_irq) and complains about a TD descriptor which is not returned. I've been looking at several things and haven't noticed anything unusual that might lead to this. The manual says "to try again" until the descriptor comes out. I limited the amount of retries to 100 retries in order to avoid an infinite number of retries and so a busy-loop. Back then testing revealed that the number of retries were around 20-30 so 100 seemed a good upper limit. This g_zero test reaches without a problem 98 retries and it jumps sometimes to 101 on am335x-evm and so the WARN_ON() triggers. Same test run on beaglebone black and the retries start at 122 and my max value so far was at 128. So lets rise the limit to 500. Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2014-12-03 15:09:49 +01:00
dmaengine: cppi41: Fix runtime PM timeouts with USB mass storage 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 <andy.shevchenko@gmail.com> Cc: Bin Liu <b-liu@ti.com> Cc: Grygorii Strashko <grygorii.strashko@ti.com> Cc: Kevin Hilman <khilman@baylibre.com> Cc: Patrick Titiano <ptitiano@baylibre.com> Cc: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com> Signed-off-by: Tony Lindgren <tony@atomide.com> Tested-by: Bin Liu <b-liu@ti.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2017-01-19 08:49:07 -08:00
dmaengine: cppi41: Fix oops in cppi41_runtime_resume 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 ... [<bf0d92cc>] (cppi41_runtime_resume [cppi41]) from [<c0589838>] (__rpm_callback+0xc0/0x214) [<c0589838>] (__rpm_callback) from [<c05899ac>] (rpm_callback+0x20/0x80) [<c05899ac>] (rpm_callback) from [<c0589460>] (rpm_resume+0x504/0x78c) [<c0589460>] (rpm_resume) from [<c058a1a0>] (pm_runtime_work+0x60/0xa8) [<c058a1a0>] (pm_runtime_work) from [<c0156120>] (process_one_work+0x2b4/0x808) This is because of a race with runtime PM and cppi41_dma_issue_pending() as reported by Alexandre Bailon <abailon@baylibre.com> 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 <grygorii.strashko@ti.com> 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 <grygorii.strashko@ti.com>. Based on earlier patches from Alexandre Bailon <abailon@baylibre.com> and Grygorii Strashko <grygorii.strashko@ti.com> modified based on testing and what was discussed on the mailing lists. Fixes: fdea2d09b997 ("dmaengine: cppi41: Add basic PM runtime support") Cc: Andy Shevchenko <andy.shevchenko@gmail.com> Cc: Bin Liu <b-liu@ti.com> Cc: Grygorii Strashko <grygorii.strashko@ti.com> Cc: Kevin Hilman <khilman@baylibre.com> Cc: Patrick Titiano <ptitiano@baylibre.com> Cc: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com> Reported-by: Alexandre Bailon <abailon@baylibre.com> Signed-off-by: Tony Lindgren <tony@atomide.com> Tested-by: Bin Liu <b-liu@ti.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2017-01-19 08:49:08 -08:00
dmaengine: cppi41: Fix oops in cppi41_runtime_resume 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 ... [<bf0d92cc>] (cppi41_runtime_resume [cppi41]) from [<c0589838>] (__rpm_callback+0xc0/0x214) [<c0589838>] (__rpm_callback) from [<c05899ac>] (rpm_callback+0x20/0x80) [<c05899ac>] (rpm_callback) from [<c0589460>] (rpm_resume+0x504/0x78c) [<c0589460>] (rpm_resume) from [<c058a1a0>] (pm_runtime_work+0x60/0xa8) [<c058a1a0>] (pm_runtime_work) from [<c0156120>] (process_one_work+0x2b4/0x808) This is because of a race with runtime PM and cppi41_dma_issue_pending() as reported by Alexandre Bailon <abailon@baylibre.com> 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 <grygorii.strashko@ti.com> 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 <grygorii.strashko@ti.com>. Based on earlier patches from Alexandre Bailon <abailon@baylibre.com> and Grygorii Strashko <grygorii.strashko@ti.com> modified based on testing and what was discussed on the mailing lists. Fixes: fdea2d09b997 ("dmaengine: cppi41: Add basic PM runtime support") Cc: Andy Shevchenko <andy.shevchenko@gmail.com> Cc: Bin Liu <b-liu@ti.com> Cc: Grygorii Strashko <grygorii.strashko@ti.com> Cc: Kevin Hilman <khilman@baylibre.com> Cc: Patrick Titiano <ptitiano@baylibre.com> Cc: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com> Reported-by: Alexandre Bailon <abailon@baylibre.com> Signed-off-by: Tony Lindgren <tony@atomide.com> Tested-by: Bin Liu <b-liu@ti.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2017-01-19 08:49:08 -08:00
dmaengine: cppi41: Fix oops in cppi41_runtime_resume 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 ... [<bf0d92cc>] (cppi41_runtime_resume [cppi41]) from [<c0589838>] (__rpm_callback+0xc0/0x214) [<c0589838>] (__rpm_callback) from [<c05899ac>] (rpm_callback+0x20/0x80) [<c05899ac>] (rpm_callback) from [<c0589460>] (rpm_resume+0x504/0x78c) [<c0589460>] (rpm_resume) from [<c058a1a0>] (pm_runtime_work+0x60/0xa8) [<c058a1a0>] (pm_runtime_work) from [<c0156120>] (process_one_work+0x2b4/0x808) This is because of a race with runtime PM and cppi41_dma_issue_pending() as reported by Alexandre Bailon <abailon@baylibre.com> 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 <grygorii.strashko@ti.com> 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 <grygorii.strashko@ti.com>. Based on earlier patches from Alexandre Bailon <abailon@baylibre.com> and Grygorii Strashko <grygorii.strashko@ti.com> modified based on testing and what was discussed on the mailing lists. Fixes: fdea2d09b997 ("dmaengine: cppi41: Add basic PM runtime support") Cc: Andy Shevchenko <andy.shevchenko@gmail.com> Cc: Bin Liu <b-liu@ti.com> Cc: Grygorii Strashko <grygorii.strashko@ti.com> Cc: Kevin Hilman <khilman@baylibre.com> Cc: Patrick Titiano <ptitiano@baylibre.com> Cc: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com> Reported-by: Alexandre Bailon <abailon@baylibre.com> Signed-off-by: Tony Lindgren <tony@atomide.com> Tested-by: Bin Liu <b-liu@ti.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2017-01-19 08:49:08 -08:00
dmaengine: cppi41: Fix oops in cppi41_runtime_resume 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 ... [<bf0d92cc>] (cppi41_runtime_resume [cppi41]) from [<c0589838>] (__rpm_callback+0xc0/0x214) [<c0589838>] (__rpm_callback) from [<c05899ac>] (rpm_callback+0x20/0x80) [<c05899ac>] (rpm_callback) from [<c0589460>] (rpm_resume+0x504/0x78c) [<c0589460>] (rpm_resume) from [<c058a1a0>] (pm_runtime_work+0x60/0xa8) [<c058a1a0>] (pm_runtime_work) from [<c0156120>] (process_one_work+0x2b4/0x808) This is because of a race with runtime PM and cppi41_dma_issue_pending() as reported by Alexandre Bailon <abailon@baylibre.com> 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 <grygorii.strashko@ti.com> 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 <grygorii.strashko@ti.com>. Based on earlier patches from Alexandre Bailon <abailon@baylibre.com> and Grygorii Strashko <grygorii.strashko@ti.com> modified based on testing and what was discussed on the mailing lists. Fixes: fdea2d09b997 ("dmaengine: cppi41: Add basic PM runtime support") Cc: Andy Shevchenko <andy.shevchenko@gmail.com> Cc: Bin Liu <b-liu@ti.com> Cc: Grygorii Strashko <grygorii.strashko@ti.com> Cc: Kevin Hilman <khilman@baylibre.com> Cc: Patrick Titiano <ptitiano@baylibre.com> Cc: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com> Reported-by: Alexandre Bailon <abailon@baylibre.com> Signed-off-by: Tony Lindgren <tony@atomide.com> Tested-by: Bin Liu <b-liu@ti.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2017-01-19 08:49:08 -08:00