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author | John Keeping <john@metanate.com> | 2018-07-17 11:48:16 +0100 |
---|---|---|
committer | Vinod Koul <vkoul@kernel.org> | 2018-07-25 17:59:57 +0530 |
commit | e49756544a21f5625b379b3871d27d8500764670 (patch) | |
tree | ee855be5edc379bd8b8e13db4104b7746434c660 /drivers/dma/pl330.c | |
parent | 2f903bab92dea8dec8c93e4fa3c7c5295ef0a0fe (diff) | |
download | linux-e49756544a21f5625b379b3871d27d8500764670.tar.gz linux-e49756544a21f5625b379b3871d27d8500764670.tar.bz2 linux-e49756544a21f5625b379b3871d27d8500764670.zip |
dmaengine: pl330: fix irq race with terminate_all
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>
Diffstat (limited to 'drivers/dma/pl330.c')
-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 451370da909d..9e38947f6ffe 100644 --- a/drivers/dma/pl330.c +++ b/drivers/dma/pl330.c @@ -2256,13 +2256,14 @@ 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; |