| From 81cc6edc08705ac0146fe6ac14a0982a31ce6f3d Mon Sep 17 00:00:00 2001 |
| From: Krzysztof Kozlowski <k.kozlowski@samsung.com> |
| Date: Thu, 21 May 2015 09:34:09 +0900 |
| Subject: dmaengine: pl330: Fix hang on dmaengine_terminate_all on certain boards |
| |
| From: Krzysztof Kozlowski <k.kozlowski@samsung.com> |
| |
| commit 81cc6edc08705ac0146fe6ac14a0982a31ce6f3d upstream. |
| |
| 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") |
| Tested-by: Dinh Nguyen <dinguyen@opensource.altera.com> |
| Signed-off-by: Vinod Koul <vinod.koul@intel.com> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| |
| --- |
| drivers/dma/pl330.c | 3 +++ |
| 1 file changed, 3 insertions(+) |
| |
| --- a/drivers/dma/pl330.c |
| +++ b/drivers/dma/pl330.c |
| @@ -2127,6 +2127,7 @@ static int pl330_terminate_all(struct dm |
| struct pl330_dmac *pl330 = pch->dmac; |
| LIST_HEAD(list); |
| |
| + pm_runtime_get_sync(pl330->ddma.dev); |
| spin_lock_irqsave(&pch->lock, flags); |
| spin_lock(&pl330->lock); |
| _stop(pch->thread); |
| @@ -2151,6 +2152,8 @@ static int pl330_terminate_all(struct dm |
| list_splice_tail_init(&pch->work_list, &pl330->desc_pool); |
| list_splice_tail_init(&pch->completed_list, &pl330->desc_pool); |
| spin_unlock_irqrestore(&pch->lock, flags); |
| + pm_runtime_mark_last_busy(pl330->ddma.dev); |
| + pm_runtime_put_autosuspend(pl330->ddma.dev); |
| |
| return 0; |
| } |
