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dmaengine: at_hdmac: Fix descriptor handling when issuing it to hardware
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commit ba24236 upstream.

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: dc78baa ("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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Tudor Ambarus authored and Greg Kroah-Hartman committed Nov 16, 2022
1 parent 5482403 commit 14f5462
Showing 1 changed file with 11 additions and 4 deletions.
15 changes: 11 additions & 4 deletions drivers/dma/at_hdmac.c
Original file line number Diff line number Diff line change
Expand Up @@ -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);
}

Expand All @@ -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;

Expand All @@ -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
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