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authorTudor Ambarus <tudor.ambarus@microchip.com>2022-10-25 12:02:42 +0300
committerVinod Koul <vkoul@kernel.org>2022-11-08 08:13:57 +0300
commit06988949df8c3007ad82036d3606d8ae72ed9000 (patch)
treec3c901807d30b0e9398b33f5f6f1679be6e82337 /drivers/dma/at_hdmac.c
parentc6babed879fbe82796a601bf097649e07382db46 (diff)
downloadlinux-06988949df8c3007ad82036d3606d8ae72ed9000.tar.xz
dmaengine: at_hdmac: Fix concurrency over descriptor
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>
Diffstat (limited to 'drivers/dma/at_hdmac.c')
-rw-r--r--drivers/dma/at_hdmac.c14
1 files changed, 9 insertions, 5 deletions
diff --git a/drivers/dma/at_hdmac.c b/drivers/dma/at_hdmac.c
index f1e6fa6af6c2..2012ecc57826 100644
--- a/drivers/dma/at_hdmac.c
+++ b/drivers/dma/at_hdmac.c
@@ -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);
}
/**