diff options
| author |   Tudor Ambarus <tudor.ambarus@microchip.com> | 2021-12-15 13:01:10 +0200 |
|---|---|---|
| committer |   Vinod Koul <vkoul@kernel.org> | 2022-01-05 15:50:03 +0530 |
| commit | 18deddea9184b62941395889ff7659529c877326 (patch) | |
| tree | 544c0402227535f414435f1237fe2a7eccb7ef0b /drivers/dma/at_xdmac.c | |
| parent | dmaengine: at_xdmac: Move the free desc to the tail of the desc list (diff) | |
| download | linux-dev-18deddea9184b62941395889ff7659529c877326.tar.xz linux-dev-18deddea9184b62941395889ff7659529c877326.zip | |
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/at_xdmac.c')
| -rw-r--r-- | drivers/dma/at_xdmac.c | 17 |
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) |