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dmaengine: at_xdmac: Fix concurrency over xfers_list

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commit 18deddea91 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: e1f7c9eee7 ("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>
This commit is contained in:
Tudor Ambarus 2021-12-15 13:01:10 +02:00 committed by Greg Kroah-Hartman
parent 5a8547fc3c
commit fb8f0e827a
1 changed files with 10 additions and 7 deletions
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17
drivers/dma/at_xdmac.c
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@ -1619,14 +1619,17 @@ 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)