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authorJohn Keeping <john@metanate.com>2018-07-17 11:48:16 +0100
committerVinod Koul <vkoul@kernel.org>2018-07-25 17:59:57 +0530
commite49756544a21f5625b379b3871d27d8500764670 (patch)
treeee855be5edc379bd8b8e13db4104b7746434c660 /drivers/dma
parent2f903bab92dea8dec8c93e4fa3c7c5295ef0a0fe (diff)
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')
-rw-r--r--drivers/dma/pl330.c5
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;