From: <gregkh@linuxfoundation.org>
To: tudor.ambarus@microchip.com, nicolas.ferre@microchip.com,
peda@axentia.se, vkoul@kernel.org
Cc: <stable@vger.kernel.org>
Subject: FAILED: patch "[PATCH] dmaengine: at_hdmac: Fix premature completion of desc in" failed to apply to 5.4-stable tree
Date: Mon, 14 Nov 2022 12:07:25 +0100 [thread overview]
Message-ID: <16684240451938@kroah.com> (raw)
The patch below does not apply to the 5.4-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:
fcd37565efda ("dmaengine: at_hdmac: Fix premature completion of desc in issue_pending")
8a47221fc284 ("dmaengine: at_hdmac: Start transfer for cyclic channels in issue_pending")
078a6506141a ("dmaengine: at_hdmac: Fix deadlocks")
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From fcd37565efdaffeac179d0f0ce980ac79bfdf569 Mon Sep 17 00:00:00 2001
From: Tudor Ambarus <tudor.ambarus@microchip.com>
Date: Tue, 25 Oct 2022 12:02:38 +0300
Subject: [PATCH] dmaengine: at_hdmac: Fix premature completion of desc in
issue_pending
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: 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/20221025090306.297886-5-tudor.ambarus@microchip.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
diff --git a/drivers/dma/at_hdmac.c b/drivers/dma/at_hdmac.c
index e9d0c3632868..cb5522417db6 100644
--- a/drivers/dma/at_hdmac.c
+++ b/drivers/dma/at_hdmac.c
@@ -1527,16 +1527,26 @@ 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_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);
}
/**
reply other threads:[~2022-11-14 11:09 UTC|newest]
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