[PATCH 17/33] dmaengine: at_hdmac: Fix descriptor handling when issuing it to hardware
From: Tudor Ambarus <hidden>
Date: 2022-08-20 12:59:28
Also in:
dmaengine, lkml, stable
Subsystem:
dma generic offload engine subsystem, microchip at91 dma drivers, the rest · Maintainers:
Vinod Koul, Ludovic Desroches, Linus Torvalds
As it was before, the descriptor was issued to the hardware without adding
it to the active (issued) list. This could result in a completion of other
descriptor, or/and in the descriptor never being completed.
Fixes: dc78baa2b90b ("dmaengine: at_hdmac: new driver for the Atmel AHB DMA Controller")
Reported-by: Peter Rosin <redacted>
Cc: stable@vger.kernel.org
Signed-off-by: Tudor Ambarus <redacted>
Link: https://lore.kernel.org/lkml/13c6c9a2-6db5-c3bf-349b-4c127ad3496a@axentia.se/ (local)
---
drivers/dma/at_hdmac.c | 15 +++++++++++----
1 file changed, 11 insertions(+), 4 deletions(-)
diff --git a/drivers/dma/at_hdmac.c b/drivers/dma/at_hdmac.c
index 635c3be74399..e5ac73768d13 100644
--- a/drivers/dma/at_hdmac.c
+++ b/drivers/dma/at_hdmac.c@@ -945,8 +945,11 @@ static void atc_advance_work(struct at_dma_chan *atchan) /* advance work */ spin_lock_irqsave(&atchan->lock, flags); - if (!list_empty(&atchan->active_list)) - atc_dostart(atchan, atc_first_active(atchan)); + if (!list_empty(&atchan->active_list)) { + desc = atc_first_queued(atchan); + list_move_tail(&desc->desc_node, &atchan->active_list); + atc_dostart(atchan, desc); + } spin_unlock_irqrestore(&atchan->lock, flags); }
@@ -958,6 +961,7 @@ static void atc_advance_work(struct at_dma_chan *atchan) static void atc_handle_error(struct at_dma_chan *atchan) { struct at_desc *bad_desc; + struct at_desc *desc; struct at_desc *child; unsigned long flags;
@@ -975,8 +979,11 @@ static void atc_handle_error(struct at_dma_chan *atchan) list_splice_init(&atchan->queue, atchan->active_list.prev); /* Try to restart the controller */ - if (!list_empty(&atchan->active_list)) - atc_dostart(atchan, atc_first_active(atchan)); + if (!list_empty(&atchan->active_list)) { + desc = atc_first_queued(atchan); + list_move_tail(&desc->desc_node, &atchan->active_list); + atc_dostart(atchan, desc); + } /* * KERN_CRITICAL may seem harsh, but since this only happens
--
2.25.1
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