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(a)vger.kernel.org>.
Possible dependencies:
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 c6babed879fbe82796a601bf097649e07382db46 Mon Sep 17 00:00:00 2001
From: Tudor Ambarus <tudor.ambarus(a)microchip.com>
Date: Tue, 25 Oct 2022 12:02:41 +0300
Subject: [PATCH] dmaengine: at_hdmac: Fix concurrency problems by removing
atc_complete_all()
atc_complete_all() had concurrency bugs, thus remove it:
1/ atc_complete_all() in its entirety was buggy, as when the atchan->queue
list (the one that contains descriptors that are not yet issued to the
hardware) contained descriptors, it fired just the first from the
atchan->queue, but moved all the desc from atchan->queue to
atchan->active_list and considered them all as fired. This could result in
calling the completion of a descriptor that was not yet issued to the
hardware.
2/ when in tasklet at atc_advance_work() time, atchan->active_list was
queried without holding the lock of the chan. This can result in
atchan->active_list concurrency problems between the tasklet and
issue_pending().
Fixes: dc78baa2b90b ("dmaengine: at_hdmac: new driver for the Atmel AHB DMA Controller")
Reported-by: Peter Rosin <peda(a)axentia.se>
Signed-off-by: Tudor Ambarus <tudor.ambarus(a)microchip.com>
Cc: stable(a)vger.kernel.org
Link: https://lore.kernel.org/lkml/13c6c9a2-6db5-c3bf-349b-4c127ad3496a@axentia.s…
Acked-by: Nicolas Ferre <nicolas.ferre(a)microchip.com>
Link: https://lore.kernel.org/r/20221025090306.297886-1-tudor.ambarus@microchip.c…
Link: https://lore.kernel.org/r/20221025090306.297886-8-tudor.ambarus@microchip.c…
Signed-off-by: Vinod Koul <vkoul(a)kernel.org>
diff --git a/drivers/dma/at_hdmac.c b/drivers/dma/at_hdmac.c
index deb4c6027436..f1e6fa6af6c2 100644
--- a/drivers/dma/at_hdmac.c
+++ b/drivers/dma/at_hdmac.c
@@ -485,42 +485,6 @@ atc_chain_complete(struct at_dma_chan *atchan, struct at_desc *desc)
dma_run_dependencies(txd);
}
-/**
- * atc_complete_all - finish work for all transactions
- * @atchan: channel to complete transactions for
- *
- * Eventually submit queued descriptors if any
- *
- * Assume channel is idle while calling this function
- * Called with atchan->lock held and bh disabled
- */
-static void atc_complete_all(struct at_dma_chan *atchan)
-{
- struct at_desc *desc, *_desc;
- LIST_HEAD(list);
- unsigned long flags;
-
- dev_vdbg(chan2dev(&atchan->chan_common), "complete all\n");
-
- spin_lock_irqsave(&atchan->lock, flags);
-
- /*
- * Submit queued descriptors ASAP, i.e. before we go through
- * the completed ones.
- */
- if (!list_empty(&atchan->queue))
- atc_dostart(atchan, atc_first_queued(atchan));
- /* empty active_list now it is completed */
- list_splice_init(&atchan->active_list, &list);
- /* empty queue list by moving descriptors (if any) to active_list */
- list_splice_init(&atchan->queue, &atchan->active_list);
-
- spin_unlock_irqrestore(&atchan->lock, flags);
-
- list_for_each_entry_safe(desc, _desc, &list, desc_node)
- atc_chain_complete(atchan, desc);
-}
-
/**
* atc_advance_work - at the end of a transaction, move forward
* @atchan: channel where the transaction ended
@@ -528,25 +492,20 @@ static void atc_complete_all(struct at_dma_chan *atchan)
static void atc_advance_work(struct at_dma_chan *atchan)
{
unsigned long flags;
- int ret;
dev_vdbg(chan2dev(&atchan->chan_common), "advance_work\n");
spin_lock_irqsave(&atchan->lock, flags);
- ret = atc_chan_is_enabled(atchan);
+ if (atc_chan_is_enabled(atchan) || list_empty(&atchan->active_list))
+ return spin_unlock_irqrestore(&atchan->lock, flags);
spin_unlock_irqrestore(&atchan->lock, flags);
- if (ret)
- return;
-
- if (list_empty(&atchan->active_list) ||
- list_is_singular(&atchan->active_list))
- return atc_complete_all(atchan);
atc_chain_complete(atchan, atc_first_active(atchan));
/* advance work */
spin_lock_irqsave(&atchan->lock, flags);
- atc_dostart(atchan, atc_first_active(atchan));
+ if (!list_empty(&atchan->active_list))
+ atc_dostart(atchan, atc_first_active(atchan));
spin_unlock_irqrestore(&atchan->lock, flags);
}
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(a)vger.kernel.org>.
Possible dependencies:
f645f85ae110 ("dmaengine: at_hdmac: Do not call the complete callback on device_terminate_all")
078a6506141a ("dmaengine: at_hdmac: Fix deadlocks")
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From f645f85ae1104f8bd882f962ac0a69a1070076dd Mon Sep 17 00:00:00 2001
From: Tudor Ambarus <tudor.ambarus(a)microchip.com>
Date: Tue, 25 Oct 2022 12:02:39 +0300
Subject: [PATCH] dmaengine: at_hdmac: Do not call the complete callback on
device_terminate_all
The method was wrong because it violated the dmaengine API. For aborted
transfers the complete callback should not be called. Fix the behavior and
do not call the complete callback on device_terminate_all.
Fixes: 808347f6a317 ("dmaengine: at_hdmac: add DMA slave transfers")
Reported-by: Peter Rosin <peda(a)axentia.se>
Signed-off-by: Tudor Ambarus <tudor.ambarus(a)microchip.com>
Cc: stable(a)vger.kernel.org
Link: https://lore.kernel.org/lkml/13c6c9a2-6db5-c3bf-349b-4c127ad3496a@axentia.s…
Acked-by: Nicolas Ferre <nicolas.ferre(a)microchip.com>
Link: https://lore.kernel.org/r/20221025090306.297886-1-tudor.ambarus@microchip.c…
Link: https://lore.kernel.org/r/20221025090306.297886-6-tudor.ambarus@microchip.c…
Signed-off-by: Vinod Koul <vkoul(a)kernel.org>
diff --git a/drivers/dma/at_hdmac.c b/drivers/dma/at_hdmac.c
index cb5522417db6..11816484843e 100644
--- a/drivers/dma/at_hdmac.c
+++ b/drivers/dma/at_hdmac.c
@@ -1437,11 +1437,8 @@ static int atc_terminate_all(struct dma_chan *chan)
struct at_dma_chan *atchan = to_at_dma_chan(chan);
struct at_dma *atdma = to_at_dma(chan->device);
int chan_id = atchan->chan_common.chan_id;
- struct at_desc *desc, *_desc;
unsigned long flags;
- LIST_HEAD(list);
-
dev_vdbg(chan2dev(chan), "%s\n", __func__);
/*
@@ -1460,15 +1457,11 @@ static int atc_terminate_all(struct dma_chan *chan)
cpu_relax();
/* active_list entries will end up before queued entries */
- list_splice_init(&atchan->queue, &list);
- list_splice_init(&atchan->active_list, &list);
+ list_splice_tail_init(&atchan->queue, &atchan->free_list);
+ list_splice_tail_init(&atchan->active_list, &atchan->free_list);
spin_unlock_irqrestore(&atchan->lock, flags);
- /* Flush all pending and queued descriptors */
- list_for_each_entry_safe(desc, _desc, &list, desc_node)
- atc_chain_complete(atchan, desc);
-
clear_bit(ATC_IS_PAUSED, &atchan->status);
/* if channel dedicated to cyclic operations, free it */
clear_bit(ATC_IS_CYCLIC, &atchan->status);
The patch below does not apply to the 4.14-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(a)vger.kernel.org>.
Possible dependencies:
f645f85ae110 ("dmaengine: at_hdmac: Do not call the complete callback on device_terminate_all")
078a6506141a ("dmaengine: at_hdmac: Fix deadlocks")
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From f645f85ae1104f8bd882f962ac0a69a1070076dd Mon Sep 17 00:00:00 2001
From: Tudor Ambarus <tudor.ambarus(a)microchip.com>
Date: Tue, 25 Oct 2022 12:02:39 +0300
Subject: [PATCH] dmaengine: at_hdmac: Do not call the complete callback on
device_terminate_all
The method was wrong because it violated the dmaengine API. For aborted
transfers the complete callback should not be called. Fix the behavior and
do not call the complete callback on device_terminate_all.
Fixes: 808347f6a317 ("dmaengine: at_hdmac: add DMA slave transfers")
Reported-by: Peter Rosin <peda(a)axentia.se>
Signed-off-by: Tudor Ambarus <tudor.ambarus(a)microchip.com>
Cc: stable(a)vger.kernel.org
Link: https://lore.kernel.org/lkml/13c6c9a2-6db5-c3bf-349b-4c127ad3496a@axentia.s…
Acked-by: Nicolas Ferre <nicolas.ferre(a)microchip.com>
Link: https://lore.kernel.org/r/20221025090306.297886-1-tudor.ambarus@microchip.c…
Link: https://lore.kernel.org/r/20221025090306.297886-6-tudor.ambarus@microchip.c…
Signed-off-by: Vinod Koul <vkoul(a)kernel.org>
diff --git a/drivers/dma/at_hdmac.c b/drivers/dma/at_hdmac.c
index cb5522417db6..11816484843e 100644
--- a/drivers/dma/at_hdmac.c
+++ b/drivers/dma/at_hdmac.c
@@ -1437,11 +1437,8 @@ static int atc_terminate_all(struct dma_chan *chan)
struct at_dma_chan *atchan = to_at_dma_chan(chan);
struct at_dma *atdma = to_at_dma(chan->device);
int chan_id = atchan->chan_common.chan_id;
- struct at_desc *desc, *_desc;
unsigned long flags;
- LIST_HEAD(list);
-
dev_vdbg(chan2dev(chan), "%s\n", __func__);
/*
@@ -1460,15 +1457,11 @@ static int atc_terminate_all(struct dma_chan *chan)
cpu_relax();
/* active_list entries will end up before queued entries */
- list_splice_init(&atchan->queue, &list);
- list_splice_init(&atchan->active_list, &list);
+ list_splice_tail_init(&atchan->queue, &atchan->free_list);
+ list_splice_tail_init(&atchan->active_list, &atchan->free_list);
spin_unlock_irqrestore(&atchan->lock, flags);
- /* Flush all pending and queued descriptors */
- list_for_each_entry_safe(desc, _desc, &list, desc_node)
- atc_chain_complete(atchan, desc);
-
clear_bit(ATC_IS_PAUSED, &atchan->status);
/* if channel dedicated to cyclic operations, free it */
clear_bit(ATC_IS_CYCLIC, &atchan->status);
The patch below does not apply to the 4.19-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(a)vger.kernel.org>.
Possible dependencies:
f645f85ae110 ("dmaengine: at_hdmac: Do not call the complete callback on device_terminate_all")
078a6506141a ("dmaengine: at_hdmac: Fix deadlocks")
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From f645f85ae1104f8bd882f962ac0a69a1070076dd Mon Sep 17 00:00:00 2001
From: Tudor Ambarus <tudor.ambarus(a)microchip.com>
Date: Tue, 25 Oct 2022 12:02:39 +0300
Subject: [PATCH] dmaengine: at_hdmac: Do not call the complete callback on
device_terminate_all
The method was wrong because it violated the dmaengine API. For aborted
transfers the complete callback should not be called. Fix the behavior and
do not call the complete callback on device_terminate_all.
Fixes: 808347f6a317 ("dmaengine: at_hdmac: add DMA slave transfers")
Reported-by: Peter Rosin <peda(a)axentia.se>
Signed-off-by: Tudor Ambarus <tudor.ambarus(a)microchip.com>
Cc: stable(a)vger.kernel.org
Link: https://lore.kernel.org/lkml/13c6c9a2-6db5-c3bf-349b-4c127ad3496a@axentia.s…
Acked-by: Nicolas Ferre <nicolas.ferre(a)microchip.com>
Link: https://lore.kernel.org/r/20221025090306.297886-1-tudor.ambarus@microchip.c…
Link: https://lore.kernel.org/r/20221025090306.297886-6-tudor.ambarus@microchip.c…
Signed-off-by: Vinod Koul <vkoul(a)kernel.org>
diff --git a/drivers/dma/at_hdmac.c b/drivers/dma/at_hdmac.c
index cb5522417db6..11816484843e 100644
--- a/drivers/dma/at_hdmac.c
+++ b/drivers/dma/at_hdmac.c
@@ -1437,11 +1437,8 @@ static int atc_terminate_all(struct dma_chan *chan)
struct at_dma_chan *atchan = to_at_dma_chan(chan);
struct at_dma *atdma = to_at_dma(chan->device);
int chan_id = atchan->chan_common.chan_id;
- struct at_desc *desc, *_desc;
unsigned long flags;
- LIST_HEAD(list);
-
dev_vdbg(chan2dev(chan), "%s\n", __func__);
/*
@@ -1460,15 +1457,11 @@ static int atc_terminate_all(struct dma_chan *chan)
cpu_relax();
/* active_list entries will end up before queued entries */
- list_splice_init(&atchan->queue, &list);
- list_splice_init(&atchan->active_list, &list);
+ list_splice_tail_init(&atchan->queue, &atchan->free_list);
+ list_splice_tail_init(&atchan->active_list, &atchan->free_list);
spin_unlock_irqrestore(&atchan->lock, flags);
- /* Flush all pending and queued descriptors */
- list_for_each_entry_safe(desc, _desc, &list, desc_node)
- atc_chain_complete(atchan, desc);
-
clear_bit(ATC_IS_PAUSED, &atchan->status);
/* if channel dedicated to cyclic operations, free it */
clear_bit(ATC_IS_CYCLIC, &atchan->status);
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(a)vger.kernel.org>.
Possible dependencies:
f645f85ae110 ("dmaengine: at_hdmac: Do not call the complete callback on device_terminate_all")
078a6506141a ("dmaengine: at_hdmac: Fix deadlocks")
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From f645f85ae1104f8bd882f962ac0a69a1070076dd Mon Sep 17 00:00:00 2001
From: Tudor Ambarus <tudor.ambarus(a)microchip.com>
Date: Tue, 25 Oct 2022 12:02:39 +0300
Subject: [PATCH] dmaengine: at_hdmac: Do not call the complete callback on
device_terminate_all
The method was wrong because it violated the dmaengine API. For aborted
transfers the complete callback should not be called. Fix the behavior and
do not call the complete callback on device_terminate_all.
Fixes: 808347f6a317 ("dmaengine: at_hdmac: add DMA slave transfers")
Reported-by: Peter Rosin <peda(a)axentia.se>
Signed-off-by: Tudor Ambarus <tudor.ambarus(a)microchip.com>
Cc: stable(a)vger.kernel.org
Link: https://lore.kernel.org/lkml/13c6c9a2-6db5-c3bf-349b-4c127ad3496a@axentia.s…
Acked-by: Nicolas Ferre <nicolas.ferre(a)microchip.com>
Link: https://lore.kernel.org/r/20221025090306.297886-1-tudor.ambarus@microchip.c…
Link: https://lore.kernel.org/r/20221025090306.297886-6-tudor.ambarus@microchip.c…
Signed-off-by: Vinod Koul <vkoul(a)kernel.org>
diff --git a/drivers/dma/at_hdmac.c b/drivers/dma/at_hdmac.c
index cb5522417db6..11816484843e 100644
--- a/drivers/dma/at_hdmac.c
+++ b/drivers/dma/at_hdmac.c
@@ -1437,11 +1437,8 @@ static int atc_terminate_all(struct dma_chan *chan)
struct at_dma_chan *atchan = to_at_dma_chan(chan);
struct at_dma *atdma = to_at_dma(chan->device);
int chan_id = atchan->chan_common.chan_id;
- struct at_desc *desc, *_desc;
unsigned long flags;
- LIST_HEAD(list);
-
dev_vdbg(chan2dev(chan), "%s\n", __func__);
/*
@@ -1460,15 +1457,11 @@ static int atc_terminate_all(struct dma_chan *chan)
cpu_relax();
/* active_list entries will end up before queued entries */
- list_splice_init(&atchan->queue, &list);
- list_splice_init(&atchan->active_list, &list);
+ list_splice_tail_init(&atchan->queue, &atchan->free_list);
+ list_splice_tail_init(&atchan->active_list, &atchan->free_list);
spin_unlock_irqrestore(&atchan->lock, flags);
- /* Flush all pending and queued descriptors */
- list_for_each_entry_safe(desc, _desc, &list, desc_node)
- atc_chain_complete(atchan, desc);
-
clear_bit(ATC_IS_PAUSED, &atchan->status);
/* if channel dedicated to cyclic operations, free it */
clear_bit(ATC_IS_CYCLIC, &atchan->status);
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(a)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(a)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(a)axentia.se>
Signed-off-by: Tudor Ambarus <tudor.ambarus(a)microchip.com>
Cc: stable(a)vger.kernel.org
Link: https://lore.kernel.org/lkml/13c6c9a2-6db5-c3bf-349b-4c127ad3496a@axentia.s…
Acked-by: Nicolas Ferre <nicolas.ferre(a)microchip.com>
Link: https://lore.kernel.org/r/20221025090306.297886-1-tudor.ambarus@microchip.c…
Link: https://lore.kernel.org/r/20221025090306.297886-5-tudor.ambarus@microchip.c…
Signed-off-by: Vinod Koul <vkoul(a)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);
}
/**
The patch below does not apply to the 4.14-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(a)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(a)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(a)axentia.se>
Signed-off-by: Tudor Ambarus <tudor.ambarus(a)microchip.com>
Cc: stable(a)vger.kernel.org
Link: https://lore.kernel.org/lkml/13c6c9a2-6db5-c3bf-349b-4c127ad3496a@axentia.s…
Acked-by: Nicolas Ferre <nicolas.ferre(a)microchip.com>
Link: https://lore.kernel.org/r/20221025090306.297886-1-tudor.ambarus@microchip.c…
Link: https://lore.kernel.org/r/20221025090306.297886-5-tudor.ambarus@microchip.c…
Signed-off-by: Vinod Koul <vkoul(a)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);
}
/**
The patch below does not apply to the 4.19-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(a)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(a)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(a)axentia.se>
Signed-off-by: Tudor Ambarus <tudor.ambarus(a)microchip.com>
Cc: stable(a)vger.kernel.org
Link: https://lore.kernel.org/lkml/13c6c9a2-6db5-c3bf-349b-4c127ad3496a@axentia.s…
Acked-by: Nicolas Ferre <nicolas.ferre(a)microchip.com>
Link: https://lore.kernel.org/r/20221025090306.297886-1-tudor.ambarus@microchip.c…
Link: https://lore.kernel.org/r/20221025090306.297886-5-tudor.ambarus@microchip.c…
Signed-off-by: Vinod Koul <vkoul(a)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);
}
/**
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(a)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(a)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(a)axentia.se>
Signed-off-by: Tudor Ambarus <tudor.ambarus(a)microchip.com>
Cc: stable(a)vger.kernel.org
Link: https://lore.kernel.org/lkml/13c6c9a2-6db5-c3bf-349b-4c127ad3496a@axentia.s…
Acked-by: Nicolas Ferre <nicolas.ferre(a)microchip.com>
Link: https://lore.kernel.org/r/20221025090306.297886-1-tudor.ambarus@microchip.c…
Link: https://lore.kernel.org/r/20221025090306.297886-5-tudor.ambarus@microchip.c…
Signed-off-by: Vinod Koul <vkoul(a)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);
}
/**
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(a)vger.kernel.org>.
Possible dependencies:
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 8a47221fc28417ff8a32a4f92d4448a56c3cf7e1 Mon Sep 17 00:00:00 2001
From: Tudor Ambarus <tudor.ambarus(a)microchip.com>
Date: Tue, 25 Oct 2022 12:02:37 +0300
Subject: [PATCH] dmaengine: at_hdmac: Start transfer for cyclic channels in
issue_pending
Cyclic channels must too call issue_pending in order to start a transfer.
Start the transfer in issue_pending regardless of the type of channel.
This wrongly worked before, because in the past the transfer was started
at tx_submit level when only a desc in the transfer list.
Fixes: 53830cc75974 ("dmaengine: at_hdmac: add cyclic DMA operation support")
Reported-by: Peter Rosin <peda(a)axentia.se>
Signed-off-by: Tudor Ambarus <tudor.ambarus(a)microchip.com>
Cc: stable(a)vger.kernel.org
Link: https://lore.kernel.org/lkml/13c6c9a2-6db5-c3bf-349b-4c127ad3496a@axentia.s…
Acked-by: Nicolas Ferre <nicolas.ferre(a)microchip.com>
Link: https://lore.kernel.org/r/20221025090306.297886-1-tudor.ambarus@microchip.c…
Link: https://lore.kernel.org/r/20221025090306.297886-4-tudor.ambarus@microchip.c…
Signed-off-by: Vinod Koul <vkoul(a)kernel.org>
diff --git a/drivers/dma/at_hdmac.c b/drivers/dma/at_hdmac.c
index 3f71f4d2f467..e9d0c3632868 100644
--- a/drivers/dma/at_hdmac.c
+++ b/drivers/dma/at_hdmac.c
@@ -1536,10 +1536,6 @@ static void atc_issue_pending(struct dma_chan *chan)
dev_vdbg(chan2dev(chan), "issue_pending\n");
- /* Not needed for cyclic transfers */
- if (atc_chan_is_cyclic(atchan))
- return;
-
atc_advance_work(atchan);
}