The patch below does not apply to the 4.4-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>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From b63e5cb94ad6947ab5fe38b5a9417dcfd0bc6122 Mon Sep 17 00:00:00 2001
From: Tudor Ambarus <tudor.ambarus(a)microchip.com>
Date: Wed, 15 Dec 2021 13:01:08 +0200
Subject: [PATCH] dmaengine: at_xdmac: Fix race for the tx desc callback
The transfer descriptors were wrongly moved to the free descriptors list
before calling the tx desc callback. As the DMA engine drivers drop any
locks before calling the callback function, txd could be taken again,
resulting in its callback called prematurely. Fix the race for the tx desc
callback by moving the xfer desc into the free desc list after the
callback is invoked.
Fixes: e1f7c9eee707 ("dmaengine: at_xdmac: creation of the atmel eXtended DMA Controller driver")
Signed-off-by: Tudor Ambarus <tudor.ambarus(a)microchip.com>
Link: https://lore.kernel.org/r/20211215110115.191749-6-tudor.ambarus@microchip.c…
Signed-off-by: Vinod Koul <vkoul(a)kernel.org>
diff --git a/drivers/dma/at_xdmac.c b/drivers/dma/at_xdmac.c
index 83c031207530..d5b37459f906 100644
--- a/drivers/dma/at_xdmac.c
+++ b/drivers/dma/at_xdmac.c
@@ -1582,20 +1582,6 @@ at_xdmac_tx_status(struct dma_chan *chan, dma_cookie_t cookie,
return ret;
}
-/* Call must be protected by lock. */
-static void at_xdmac_remove_xfer(struct at_xdmac_chan *atchan,
- struct at_xdmac_desc *desc)
-{
- dev_dbg(chan2dev(&atchan->chan), "%s: desc 0x%p\n", __func__, desc);
-
- /*
- * Remove the transfer from the transfer list then move the transfer
- * descriptors into the free descriptors list.
- */
- list_del(&desc->xfer_node);
- list_splice_init(&desc->descs_list, &atchan->free_descs_list);
-}
-
static void at_xdmac_advance_work(struct at_xdmac_chan *atchan)
{
struct at_xdmac_desc *desc;
@@ -1704,7 +1690,8 @@ static void at_xdmac_tasklet(struct tasklet_struct *t)
txd = &desc->tx_dma_desc;
dma_cookie_complete(txd);
- at_xdmac_remove_xfer(atchan, desc);
+ /* Remove the transfer from the transfer list. */
+ list_del(&desc->xfer_node);
spin_unlock_irq(&atchan->lock);
if (txd->flags & DMA_PREP_INTERRUPT)
@@ -1713,6 +1700,8 @@ static void at_xdmac_tasklet(struct tasklet_struct *t)
dma_run_dependencies(txd);
spin_lock_irq(&atchan->lock);
+ /* Move the xfer descriptors into the free descriptors list. */
+ list_splice_init(&desc->descs_list, &atchan->free_descs_list);
at_xdmac_advance_work(atchan);
spin_unlock_irq(&atchan->lock);
}
@@ -1859,8 +1848,10 @@ static int at_xdmac_device_terminate_all(struct dma_chan *chan)
cpu_relax();
/* Cancel all pending transfers. */
- list_for_each_entry_safe(desc, _desc, &atchan->xfers_list, xfer_node)
- at_xdmac_remove_xfer(atchan, desc);
+ list_for_each_entry_safe(desc, _desc, &atchan->xfers_list, xfer_node) {
+ list_del(&desc->xfer_node);
+ list_splice_init(&desc->descs_list, &atchan->free_descs_list);
+ }
clear_bit(AT_XDMAC_CHAN_IS_PAUSED, &atchan->status);
clear_bit(AT_XDMAC_CHAN_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>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 18deddea9184b62941395889ff7659529c877326 Mon Sep 17 00:00:00 2001
From: Tudor Ambarus <tudor.ambarus(a)microchip.com>
Date: Wed, 15 Dec 2021 13:01:10 +0200
Subject: [PATCH] dmaengine: at_xdmac: Fix concurrency over xfers_list
Since tx_submit can be called from a hard IRQ, xfers_list must be
protected with a lock to avoid concurency on the list's elements.
Since at_xdmac_handle_cyclic() is called from a tasklet, spin_lock_irq
is enough to protect from a hard IRQ.
Fixes: e1f7c9eee707 ("dmaengine: at_xdmac: creation of the atmel eXtended DMA Controller driver")
Signed-off-by: Tudor Ambarus <tudor.ambarus(a)microchip.com>
Link: https://lore.kernel.org/r/20211215110115.191749-8-tudor.ambarus@microchip.c…
Signed-off-by: Vinod Koul <vkoul(a)kernel.org>
diff --git a/drivers/dma/at_xdmac.c b/drivers/dma/at_xdmac.c
index b6547f1b5645..eeb03065d484 100644
--- a/drivers/dma/at_xdmac.c
+++ b/drivers/dma/at_xdmac.c
@@ -1608,14 +1608,17 @@ static void at_xdmac_handle_cyclic(struct at_xdmac_chan *atchan)
struct at_xdmac_desc *desc;
struct dma_async_tx_descriptor *txd;
- if (!list_empty(&atchan->xfers_list)) {
- desc = list_first_entry(&atchan->xfers_list,
- struct at_xdmac_desc, xfer_node);
- txd = &desc->tx_dma_desc;
-
- if (txd->flags & DMA_PREP_INTERRUPT)
- dmaengine_desc_get_callback_invoke(txd, NULL);
+ spin_lock_irq(&atchan->lock);
+ if (list_empty(&atchan->xfers_list)) {
+ spin_unlock_irq(&atchan->lock);
+ return;
}
+ desc = list_first_entry(&atchan->xfers_list, struct at_xdmac_desc,
+ xfer_node);
+ spin_unlock_irq(&atchan->lock);
+ txd = &desc->tx_dma_desc;
+ if (txd->flags & DMA_PREP_INTERRUPT)
+ dmaengine_desc_get_callback_invoke(txd, NULL);
}
static void at_xdmac_handle_error(struct at_xdmac_chan *atchan)
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>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 18deddea9184b62941395889ff7659529c877326 Mon Sep 17 00:00:00 2001
From: Tudor Ambarus <tudor.ambarus(a)microchip.com>
Date: Wed, 15 Dec 2021 13:01:10 +0200
Subject: [PATCH] dmaengine: at_xdmac: Fix concurrency over xfers_list
Since tx_submit can be called from a hard IRQ, xfers_list must be
protected with a lock to avoid concurency on the list's elements.
Since at_xdmac_handle_cyclic() is called from a tasklet, spin_lock_irq
is enough to protect from a hard IRQ.
Fixes: e1f7c9eee707 ("dmaengine: at_xdmac: creation of the atmel eXtended DMA Controller driver")
Signed-off-by: Tudor Ambarus <tudor.ambarus(a)microchip.com>
Link: https://lore.kernel.org/r/20211215110115.191749-8-tudor.ambarus@microchip.c…
Signed-off-by: Vinod Koul <vkoul(a)kernel.org>
diff --git a/drivers/dma/at_xdmac.c b/drivers/dma/at_xdmac.c
index b6547f1b5645..eeb03065d484 100644
--- a/drivers/dma/at_xdmac.c
+++ b/drivers/dma/at_xdmac.c
@@ -1608,14 +1608,17 @@ static void at_xdmac_handle_cyclic(struct at_xdmac_chan *atchan)
struct at_xdmac_desc *desc;
struct dma_async_tx_descriptor *txd;
- if (!list_empty(&atchan->xfers_list)) {
- desc = list_first_entry(&atchan->xfers_list,
- struct at_xdmac_desc, xfer_node);
- txd = &desc->tx_dma_desc;
-
- if (txd->flags & DMA_PREP_INTERRUPT)
- dmaengine_desc_get_callback_invoke(txd, NULL);
+ spin_lock_irq(&atchan->lock);
+ if (list_empty(&atchan->xfers_list)) {
+ spin_unlock_irq(&atchan->lock);
+ return;
}
+ desc = list_first_entry(&atchan->xfers_list, struct at_xdmac_desc,
+ xfer_node);
+ spin_unlock_irq(&atchan->lock);
+ txd = &desc->tx_dma_desc;
+ if (txd->flags & DMA_PREP_INTERRUPT)
+ dmaengine_desc_get_callback_invoke(txd, NULL);
}
static void at_xdmac_handle_error(struct at_xdmac_chan *atchan)
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>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 18deddea9184b62941395889ff7659529c877326 Mon Sep 17 00:00:00 2001
From: Tudor Ambarus <tudor.ambarus(a)microchip.com>
Date: Wed, 15 Dec 2021 13:01:10 +0200
Subject: [PATCH] dmaengine: at_xdmac: Fix concurrency over xfers_list
Since tx_submit can be called from a hard IRQ, xfers_list must be
protected with a lock to avoid concurency on the list's elements.
Since at_xdmac_handle_cyclic() is called from a tasklet, spin_lock_irq
is enough to protect from a hard IRQ.
Fixes: e1f7c9eee707 ("dmaengine: at_xdmac: creation of the atmel eXtended DMA Controller driver")
Signed-off-by: Tudor Ambarus <tudor.ambarus(a)microchip.com>
Link: https://lore.kernel.org/r/20211215110115.191749-8-tudor.ambarus@microchip.c…
Signed-off-by: Vinod Koul <vkoul(a)kernel.org>
diff --git a/drivers/dma/at_xdmac.c b/drivers/dma/at_xdmac.c
index b6547f1b5645..eeb03065d484 100644
--- a/drivers/dma/at_xdmac.c
+++ b/drivers/dma/at_xdmac.c
@@ -1608,14 +1608,17 @@ static void at_xdmac_handle_cyclic(struct at_xdmac_chan *atchan)
struct at_xdmac_desc *desc;
struct dma_async_tx_descriptor *txd;
- if (!list_empty(&atchan->xfers_list)) {
- desc = list_first_entry(&atchan->xfers_list,
- struct at_xdmac_desc, xfer_node);
- txd = &desc->tx_dma_desc;
-
- if (txd->flags & DMA_PREP_INTERRUPT)
- dmaengine_desc_get_callback_invoke(txd, NULL);
+ spin_lock_irq(&atchan->lock);
+ if (list_empty(&atchan->xfers_list)) {
+ spin_unlock_irq(&atchan->lock);
+ return;
}
+ desc = list_first_entry(&atchan->xfers_list, struct at_xdmac_desc,
+ xfer_node);
+ spin_unlock_irq(&atchan->lock);
+ txd = &desc->tx_dma_desc;
+ if (txd->flags & DMA_PREP_INTERRUPT)
+ dmaengine_desc_get_callback_invoke(txd, NULL);
}
static void at_xdmac_handle_error(struct at_xdmac_chan *atchan)
The patch below does not apply to the 4.4-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>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 18deddea9184b62941395889ff7659529c877326 Mon Sep 17 00:00:00 2001
From: Tudor Ambarus <tudor.ambarus(a)microchip.com>
Date: Wed, 15 Dec 2021 13:01:10 +0200
Subject: [PATCH] dmaengine: at_xdmac: Fix concurrency over xfers_list
Since tx_submit can be called from a hard IRQ, xfers_list must be
protected with a lock to avoid concurency on the list's elements.
Since at_xdmac_handle_cyclic() is called from a tasklet, spin_lock_irq
is enough to protect from a hard IRQ.
Fixes: e1f7c9eee707 ("dmaengine: at_xdmac: creation of the atmel eXtended DMA Controller driver")
Signed-off-by: Tudor Ambarus <tudor.ambarus(a)microchip.com>
Link: https://lore.kernel.org/r/20211215110115.191749-8-tudor.ambarus@microchip.c…
Signed-off-by: Vinod Koul <vkoul(a)kernel.org>
diff --git a/drivers/dma/at_xdmac.c b/drivers/dma/at_xdmac.c
index b6547f1b5645..eeb03065d484 100644
--- a/drivers/dma/at_xdmac.c
+++ b/drivers/dma/at_xdmac.c
@@ -1608,14 +1608,17 @@ static void at_xdmac_handle_cyclic(struct at_xdmac_chan *atchan)
struct at_xdmac_desc *desc;
struct dma_async_tx_descriptor *txd;
- if (!list_empty(&atchan->xfers_list)) {
- desc = list_first_entry(&atchan->xfers_list,
- struct at_xdmac_desc, xfer_node);
- txd = &desc->tx_dma_desc;
-
- if (txd->flags & DMA_PREP_INTERRUPT)
- dmaengine_desc_get_callback_invoke(txd, NULL);
+ spin_lock_irq(&atchan->lock);
+ if (list_empty(&atchan->xfers_list)) {
+ spin_unlock_irq(&atchan->lock);
+ return;
}
+ desc = list_first_entry(&atchan->xfers_list, struct at_xdmac_desc,
+ xfer_node);
+ spin_unlock_irq(&atchan->lock);
+ txd = &desc->tx_dma_desc;
+ if (txd->flags & DMA_PREP_INTERRUPT)
+ dmaengine_desc_get_callback_invoke(txd, NULL);
}
static void at_xdmac_handle_error(struct at_xdmac_chan *atchan)
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>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From e6af9b05bec63cd4d1de2a33968cd0be2a91282a Mon Sep 17 00:00:00 2001
From: Tudor Ambarus <tudor.ambarus(a)microchip.com>
Date: Wed, 15 Dec 2021 13:01:05 +0200
Subject: [PATCH] dmaengine: at_xdmac: 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: e1f7c9eee707 ("dmaengine: at_xdmac: creation of the atmel eXtended DMA Controller driver")
Signed-off-by: Tudor Ambarus <tudor.ambarus(a)microchip.com>
Link: https://lore.kernel.org/r/20211215110115.191749-3-tudor.ambarus@microchip.c…
Signed-off-by: Vinod Koul <vkoul(a)kernel.org>
diff --git a/drivers/dma/at_xdmac.c b/drivers/dma/at_xdmac.c
index 4ff12b083136..c3d3e1270236 100644
--- a/drivers/dma/at_xdmac.c
+++ b/drivers/dma/at_xdmac.c
@@ -1778,11 +1778,9 @@ static void at_xdmac_issue_pending(struct dma_chan *chan)
dev_dbg(chan2dev(&atchan->chan), "%s\n", __func__);
- if (!at_xdmac_chan_is_cyclic(atchan)) {
- spin_lock_irqsave(&atchan->lock, flags);
- at_xdmac_advance_work(atchan);
- spin_unlock_irqrestore(&atchan->lock, flags);
- }
+ spin_lock_irqsave(&atchan->lock, flags);
+ at_xdmac_advance_work(atchan);
+ spin_unlock_irqrestore(&atchan->lock, flags);
return;
}
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>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From e6af9b05bec63cd4d1de2a33968cd0be2a91282a Mon Sep 17 00:00:00 2001
From: Tudor Ambarus <tudor.ambarus(a)microchip.com>
Date: Wed, 15 Dec 2021 13:01:05 +0200
Subject: [PATCH] dmaengine: at_xdmac: 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: e1f7c9eee707 ("dmaengine: at_xdmac: creation of the atmel eXtended DMA Controller driver")
Signed-off-by: Tudor Ambarus <tudor.ambarus(a)microchip.com>
Link: https://lore.kernel.org/r/20211215110115.191749-3-tudor.ambarus@microchip.c…
Signed-off-by: Vinod Koul <vkoul(a)kernel.org>
diff --git a/drivers/dma/at_xdmac.c b/drivers/dma/at_xdmac.c
index 4ff12b083136..c3d3e1270236 100644
--- a/drivers/dma/at_xdmac.c
+++ b/drivers/dma/at_xdmac.c
@@ -1778,11 +1778,9 @@ static void at_xdmac_issue_pending(struct dma_chan *chan)
dev_dbg(chan2dev(&atchan->chan), "%s\n", __func__);
- if (!at_xdmac_chan_is_cyclic(atchan)) {
- spin_lock_irqsave(&atchan->lock, flags);
- at_xdmac_advance_work(atchan);
- spin_unlock_irqrestore(&atchan->lock, flags);
- }
+ spin_lock_irqsave(&atchan->lock, flags);
+ at_xdmac_advance_work(atchan);
+ spin_unlock_irqrestore(&atchan->lock, flags);
return;
}
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>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From e6af9b05bec63cd4d1de2a33968cd0be2a91282a Mon Sep 17 00:00:00 2001
From: Tudor Ambarus <tudor.ambarus(a)microchip.com>
Date: Wed, 15 Dec 2021 13:01:05 +0200
Subject: [PATCH] dmaengine: at_xdmac: 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: e1f7c9eee707 ("dmaengine: at_xdmac: creation of the atmel eXtended DMA Controller driver")
Signed-off-by: Tudor Ambarus <tudor.ambarus(a)microchip.com>
Link: https://lore.kernel.org/r/20211215110115.191749-3-tudor.ambarus@microchip.c…
Signed-off-by: Vinod Koul <vkoul(a)kernel.org>
diff --git a/drivers/dma/at_xdmac.c b/drivers/dma/at_xdmac.c
index 4ff12b083136..c3d3e1270236 100644
--- a/drivers/dma/at_xdmac.c
+++ b/drivers/dma/at_xdmac.c
@@ -1778,11 +1778,9 @@ static void at_xdmac_issue_pending(struct dma_chan *chan)
dev_dbg(chan2dev(&atchan->chan), "%s\n", __func__);
- if (!at_xdmac_chan_is_cyclic(atchan)) {
- spin_lock_irqsave(&atchan->lock, flags);
- at_xdmac_advance_work(atchan);
- spin_unlock_irqrestore(&atchan->lock, flags);
- }
+ spin_lock_irqsave(&atchan->lock, flags);
+ at_xdmac_advance_work(atchan);
+ spin_unlock_irqrestore(&atchan->lock, flags);
return;
}
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>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From e6af9b05bec63cd4d1de2a33968cd0be2a91282a Mon Sep 17 00:00:00 2001
From: Tudor Ambarus <tudor.ambarus(a)microchip.com>
Date: Wed, 15 Dec 2021 13:01:05 +0200
Subject: [PATCH] dmaengine: at_xdmac: 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: e1f7c9eee707 ("dmaengine: at_xdmac: creation of the atmel eXtended DMA Controller driver")
Signed-off-by: Tudor Ambarus <tudor.ambarus(a)microchip.com>
Link: https://lore.kernel.org/r/20211215110115.191749-3-tudor.ambarus@microchip.c…
Signed-off-by: Vinod Koul <vkoul(a)kernel.org>
diff --git a/drivers/dma/at_xdmac.c b/drivers/dma/at_xdmac.c
index 4ff12b083136..c3d3e1270236 100644
--- a/drivers/dma/at_xdmac.c
+++ b/drivers/dma/at_xdmac.c
@@ -1778,11 +1778,9 @@ static void at_xdmac_issue_pending(struct dma_chan *chan)
dev_dbg(chan2dev(&atchan->chan), "%s\n", __func__);
- if (!at_xdmac_chan_is_cyclic(atchan)) {
- spin_lock_irqsave(&atchan->lock, flags);
- at_xdmac_advance_work(atchan);
- spin_unlock_irqrestore(&atchan->lock, flags);
- }
+ spin_lock_irqsave(&atchan->lock, flags);
+ at_xdmac_advance_work(atchan);
+ spin_unlock_irqrestore(&atchan->lock, flags);
return;
}
The patch below does not apply to the 4.4-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>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From e6af9b05bec63cd4d1de2a33968cd0be2a91282a Mon Sep 17 00:00:00 2001
From: Tudor Ambarus <tudor.ambarus(a)microchip.com>
Date: Wed, 15 Dec 2021 13:01:05 +0200
Subject: [PATCH] dmaengine: at_xdmac: 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: e1f7c9eee707 ("dmaengine: at_xdmac: creation of the atmel eXtended DMA Controller driver")
Signed-off-by: Tudor Ambarus <tudor.ambarus(a)microchip.com>
Link: https://lore.kernel.org/r/20211215110115.191749-3-tudor.ambarus@microchip.c…
Signed-off-by: Vinod Koul <vkoul(a)kernel.org>
diff --git a/drivers/dma/at_xdmac.c b/drivers/dma/at_xdmac.c
index 4ff12b083136..c3d3e1270236 100644
--- a/drivers/dma/at_xdmac.c
+++ b/drivers/dma/at_xdmac.c
@@ -1778,11 +1778,9 @@ static void at_xdmac_issue_pending(struct dma_chan *chan)
dev_dbg(chan2dev(&atchan->chan), "%s\n", __func__);
- if (!at_xdmac_chan_is_cyclic(atchan)) {
- spin_lock_irqsave(&atchan->lock, flags);
- at_xdmac_advance_work(atchan);
- spin_unlock_irqrestore(&atchan->lock, flags);
- }
+ spin_lock_irqsave(&atchan->lock, flags);
+ at_xdmac_advance_work(atchan);
+ spin_unlock_irqrestore(&atchan->lock, flags);
return;
}