From: Dmitry Osipenko digetx@gmail.com
commit c33ee1301c393a241d6424e36eff1071811b1064 upstream.
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 Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/dma/tegra20-apb-dma.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- 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_
/* 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;