diff options
| author | John Keeping <john@metanate.com> | 2018-07-17 13:48:16 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-09-26 09:36:31 +0300 |
| commit | ddf00feadd40a5901e9e491b6fc953c47d794e66 (patch) | |
| tree | 3ac06378da13aec8c5dc39f622791b9a5c7bc5cc | |
| parent | 8992a70297ed01f7c898f854b1edcf4a0ad4521c (diff) | |
| download | linux-ddf00feadd40a5901e9e491b6fc953c47d794e66.tar.xz | |
dmaengine: pl330: fix irq race with terminate_all
[ Upstream commit e49756544a21f5625b379b3871d27d8500764670 ]
In pl330_update() when checking if a channel has been aborted, the
channel's lock is not taken, only the overall pl330_dmac lock. But in
pl330_terminate_all() the aborted flag (req_running==-1) is set under
the channel lock and not the pl330_dmac lock.
With threaded interrupts, this leads to a potential race:
pl330_terminate_all pl330_update
------------------- ------------
lock channel
entry
lock pl330
_stop channel
unlock pl330
lock pl330
check req_running != -1
req_running = -1
_start channel
Signed-off-by: John Keeping <john@metanate.com>
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/dma/pl330.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/drivers/dma/pl330.c b/drivers/dma/pl330.c index b9dad4e40bb8..6d7e3cd4aba4 100644 --- a/drivers/dma/pl330.c +++ b/drivers/dma/pl330.c @@ -2167,13 +2167,14 @@ static int pl330_terminate_all(struct dma_chan *chan) pm_runtime_get_sync(pl330->ddma.dev); spin_lock_irqsave(&pch->lock, flags); + spin_lock(&pl330->lock); _stop(pch->thread); - spin_unlock(&pl330->lock); - pch->thread->req[0].desc = NULL; pch->thread->req[1].desc = NULL; pch->thread->req_running = -1; + spin_unlock(&pl330->lock); + power_down = pch->active; pch->active = false; |