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dmaengine: at_hdmac: Fix premature completion of desc in issue_pending

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Multiple calls to atc_issue_pending() could result in a premature
completion of a descriptor from the atchan->active list, as the method
always completed the first active descriptor from the list. Instead,
issue_pending() should just take the first transaction descriptor from the
pending queue, move it to active_list and start the transfer.

Fixes: dc78baa2b9 ("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/20221025090306.297886-5-tudor.ambarus@microchip.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
This commit is contained in:
Tudor Ambarus 2022-10-25 12:02:38 +03:00 • committed by Vinod Koul
parent 8a47221fc2
commit fcd37565ef
1 changed files with 13 additions and 3 deletions
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16
drivers/dma/at_hdmac.c
View file

@ -1527,16 +1527,26 @@ atc_tx_status(struct dma_chan *chan,
} }
/** /**
* atc_issue_pending - try to finish work * atc_issue_pending - takes the first transaction descriptor in the pending
* queue and starts the transfer.
* @chan: target DMA channel * @chan: target DMA channel
*/ */
static void atc_issue_pending(struct dma_chan *chan) static void atc_issue_pending(struct dma_chan *chan)
{ {
struct at_dma_chan *atchan = to_at_dma_chan(chan); struct at_dma_chan *atchan = to_at_dma_chan(chan);
struct at_desc *desc;
unsigned long flags;
dev_vdbg(chan2dev(chan), "issue_pending\n"); dev_vdbg(chan2dev(chan), "issue_pending\n");
atc_advance_work(atchan); spin_lock_irqsave(&atchan->lock, flags);
if (atc_chan_is_enabled(atchan) || list_empty(&atchan->queue))
return spin_unlock_irqrestore(&atchan->lock, flags);
desc = atc_first_queued(atchan);
list_move_tail(&desc->desc_node, &atchan->active_list);
atc_dostart(atchan, desc);
spin_unlock_irqrestore(&atchan->lock, flags);
} }
/** /**