Commit df7e200b authored by Tudor Ambarus's avatar Tudor Ambarus Committed by sanglipeng
Browse files

dmaengine: at_hdmac: Fix premature completion of desc in issue_pending 

stable inclusion
from stable-v5.10.155
commit 7078e935b4102a63a2473dbeeeb13dd9fefc33fb
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I7M5F4

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=7078e935b4102a63a2473dbeeeb13dd9fefc33fb



--------------------------------

commit fcd37565 upstream.

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: dc78baa2 ("dmaengine: at_hdmac: new driver for the Atmel AHB DMA Controller")
Reported-by: default avatarPeter Rosin <peda@axentia.se>
Signed-off-by: default avatarTudor 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: default avatarNicolas 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: default avatarVinod Koul <vkoul@kernel.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: default avatarsanglipeng <sanglipeng1@jd.com>
parent 79e1ac44

drivers/dma/at_hdmac.c

+13 −3
Original line number Diff line number Diff line
@@ -1500,16 +1500,26 @@ 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

 */

static void atc_issue_pending(struct 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");



	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);

}



/**