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authorTudor Ambarus <tudor.ambarus@microchip.com>2022-10-25 11:02:45 +0200
committerVinod Koul <vkoul@kernel.org>2022-11-08 06:13:57 +0100
commitba2423633ba646e1df20e30cb3cf35495c16f173 (patch)
treebfde59e72e64899932b440d280b5e0b27acc4d59 /drivers/dma
parentdmaengine: at_hdmac: Fix concurrency over the active list (diff)
downloadlinux-ba2423633ba646e1df20e30cb3cf35495c16f173.tar.xz
linux-ba2423633ba646e1df20e30cb3cf35495c16f173.zip
dmaengine: at_hdmac: Fix descriptor handling when issuing it to hardware
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 <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/20221025090306.297886-12-tudor.ambarus@microchip.com Signed-off-by: Vinod Koul <vkoul@kernel.org>
Diffstat (limited to 'drivers/dma')
-rw-r--r--drivers/dma/at_hdmac.c15
1 files changed, 11 insertions, 4 deletions
diff --git a/drivers/dma/at_hdmac.c b/drivers/dma/at_hdmac.c
index b53a9fc15dd9..9e5a30396c1c 100644
--- a/drivers/dma/at_hdmac.c
+++ b/drivers/dma/at_hdmac.c
@@ -510,8 +510,11 @@ 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);
}
@@ -523,6 +526,7 @@ 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;
@@ -540,8 +544,11 @@ 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