The patch below does not apply to the 4.9-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.
Possible dependencies:
ba2423633ba6 ("dmaengine: at_hdmac: Fix descriptor handling when issuing it to hardware") c6babed879fb ("dmaengine: at_hdmac: Fix concurrency problems by removing atc_complete_all()") 078a6506141a ("dmaengine: at_hdmac: Fix deadlocks")
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From ba2423633ba646e1df20e30cb3cf35495c16f173 Mon Sep 17 00:00:00 2001 From: Tudor Ambarus tudor.ambarus@microchip.com Date: Tue, 25 Oct 2022 12:02:45 +0300 Subject: [PATCH] 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.co... Link: https://lore.kernel.org/r/20221025090306.297886-12-tudor.ambarus@microchip.c... Signed-off-by: Vinod Koul vkoul@kernel.org
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