diff options
author | Tudor Ambarus <tudor.ambarus@microchip.com> | 2021-12-15 14:01:10 +0300 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-01-27 12:54:34 +0300 |
commit | 7ab120636d4ef854d468d8025006ef3fe2750db9 (patch) | |
tree | ba468e5bccf6990ca26d9c4684ec051aacc85a9f | |
parent | b5b27c5e3315998991fb59fc62feaf97f577b189 (diff) | |
download | linux-7ab120636d4ef854d468d8025006ef3fe2750db9.tar.xz |
dmaengine: at_xdmac: Fix concurrency over xfers_list
commit 18deddea9184b62941395889ff7659529c877326 upstream.
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-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 ebd578a47958..b3326b5e70d8 100644 --- a/drivers/dma/at_xdmac.c +++ b/drivers/dma/at_xdmac.c @@ -1559,14 +1559,17 @@ 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) |