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dmaengine: at_hdmac: Fix concurrency over descriptor

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commit 06988949df8c3007ad82036d3606d8ae72ed9000 upstream.

The descriptor was added to the free_list before calling the callback,
which could result in reissuing of the same descriptor and calling of a
single callback for both. Move the decriptor to the free list after the
callback is invoked.

Fixes: dc78baa2b90b ("dmaengine: at_hdmac: new driver for the Atmel AHB DMA Controller")
Reported-by: Peter Rosin <peda@axentia.se>
Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/lkml/13c6c9a2-6db5-c3bf-349b-4c127ad3496a@axentia.se/
Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Link: https://lore.kernel.org/r/20221025090306.297886-1-tudor.ambarus@microchip.com
Link: https://lore.kernel.org/r/20221025090306.297886-9-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 2022-10-25 12:02:42 +03:00 committed by Greg Kroah-Hartman
parent 1ee012d452
commit 8fd36e069d
1 changed files with 9 additions and 5 deletions
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14
drivers/dma/at_hdmac.c
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@ -469,11 +469,8 @@ atc_chain_complete(struct at_dma_chan *atchan, struct at_desc *desc)
desc->memset_buffer = false;
}
/* move children to free_list */
list_splice_init(&desc->tx_list, &atchan->free_list);
/* move myself to free_list */
list_move(&desc->desc_node, &atchan->free_list);
/* Remove transfer node from the active list. */
list_del_init(&desc->desc_node);
spin_unlock_irqrestore(&atchan->lock, flags);
dma_descriptor_unmap(txd);
@ -483,6 +480,13 @@ atc_chain_complete(struct at_dma_chan *atchan, struct at_desc *desc)
dmaengine_desc_get_callback_invoke(txd, NULL);
dma_run_dependencies(txd);
spin_lock_irqsave(&atchan->lock, flags);
/* move children to free_list */
list_splice_init(&desc->tx_list, &atchan->free_list);
/* add myself to free_list */
list_add(&desc->desc_node, &atchan->free_list);
spin_unlock_irqrestore(&atchan->lock, flags);
}
/**