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authorTudor Ambarus <tudor.ambarus@microchip.com>2021-12-15 13:01:10 +0200
committerVinod Koul <vkoul@kernel.org>2022-01-05 15:50:03 +0530
commit18deddea9184b62941395889ff7659529c877326 (patch)
tree544c0402227535f414435f1237fe2a7eccb7ef0b /drivers/dma
parent801db90bf294f647b967e8d99b9ae121bea63d0d (diff)
dmaengine: at_xdmac: Fix concurrency over xfers_list
Since tx_submit can be called from a hard IRQ, xfers_list must be protected with a lock to avoid concurency on the list's elements. Since at_xdmac_handle_cyclic() is called from a tasklet, spin_lock_irq is enough to protect from a hard IRQ. Fixes: e1f7c9eee707 ("dmaengine: at_xdmac: creation of the atmel eXtended DMA Controller driver") Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com> Link: https://lore.kernel.org/r/20211215110115.191749-8-tudor.ambarus@microchip.com Signed-off-by: Vinod Koul <vkoul@kernel.org>
Diffstat (limited to 'drivers/dma')
-rw-r--r--drivers/dma/at_xdmac.c17
1 files changed, 10 insertions, 7 deletions
diff --git a/drivers/dma/at_xdmac.c b/drivers/dma/at_xdmac.c
index b6547f1b5645..eeb03065d484 100644
--- a/drivers/dma/at_xdmac.c
+++ b/drivers/dma/at_xdmac.c
@@ -1608,14 +1608,17 @@ static void at_xdmac_handle_cyclic(struct at_xdmac_chan *atchan)
struct at_xdmac_desc *desc;
struct dma_async_tx_descriptor *txd;
- if (!list_empty(&atchan->xfers_list)) {
- desc = list_first_entry(&atchan->xfers_list,
- struct at_xdmac_desc, xfer_node);
- txd = &desc->tx_dma_desc;
-
- if (txd->flags & DMA_PREP_INTERRUPT)
- dmaengine_desc_get_callback_invoke(txd, NULL);
+ spin_lock_irq(&atchan->lock);
+ if (list_empty(&atchan->xfers_list)) {
+ spin_unlock_irq(&atchan->lock);
+ return;
}
+ desc = list_first_entry(&atchan->xfers_list, struct at_xdmac_desc,
+ xfer_node);
+ spin_unlock_irq(&atchan->lock);
+ txd = &desc->tx_dma_desc;
+ if (txd->flags & DMA_PREP_INTERRUPT)
+ dmaengine_desc_get_callback_invoke(txd, NULL);
}
static void at_xdmac_handle_error(struct at_xdmac_chan *atchan)