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dmaengine: tegra-apb: Prevent race conditions of tasklet vs free list
authorDmitry Osipenko <digetx@gmail.com>
Sun, 9 Feb 2020 16:33:39 +0000 (19:33 +0300)
committerVinod Koul <vkoul@kernel.org>
Tue, 25 Feb 2020 06:27:09 +0000 (11:57 +0530)
commitc33ee1301c393a241d6424e36eff1071811b1064
tree820e2729f28c84d740298a984bf0e0f65c9e3cf4
parent94788af4ed039476ff3527b0e6a12c1dc42cb022
dmaengine: tegra-apb: Prevent race conditions of tasklet vs free list

The interrupt handler puts a half-completed DMA descriptor on a free list
and then schedules tasklet to process bottom half of the descriptor that
executes client's callback, this creates possibility to pick up the busy
descriptor from the free list. Thus, let's disallow descriptor's re-use
until it is fully processed.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Acked-by: Jon Hunter <jonathanh@nvidia.com>
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20200209163356.6439-3-digetx@gmail.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
drivers/dma/tegra20-apb-dma.c