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authorDmitry Osipenko <digetx@gmail.com>2020-02-09 19:33:39 +0300
committerVinod Koul <vkoul@kernel.org>2020-02-25 09:27:09 +0300
commitc33ee1301c393a241d6424e36eff1071811b1064 (patch)
tree820e2729f28c84d740298a984bf0e0f65c9e3cf4 /drivers/dma
parent94788af4ed039476ff3527b0e6a12c1dc42cb022 (diff)
downloadlinux-c33ee1301c393a241d6424e36eff1071811b1064.tar.xz
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>
Diffstat (limited to 'drivers/dma')
-rw-r--r--drivers/dma/tegra20-apb-dma.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/dma/tegra20-apb-dma.c b/drivers/dma/tegra20-apb-dma.c
index 319f31d27014..4a750e29bfb5 100644
--- a/drivers/dma/tegra20-apb-dma.c
+++ b/drivers/dma/tegra20-apb-dma.c
@@ -281,7 +281,7 @@ static struct tegra_dma_desc *tegra_dma_desc_get(
/* Do not allocate if desc are waiting for ack */
list_for_each_entry(dma_desc, &tdc->free_dma_desc, node) {
- if (async_tx_test_ack(&dma_desc->txd)) {
+ if (async_tx_test_ack(&dma_desc->txd) && !dma_desc->cb_count) {
list_del(&dma_desc->node);
spin_unlock_irqrestore(&tdc->lock, flags);
dma_desc->txd.flags = 0;