FAILED: patch "[PATCH] i2c: mxs: fix DMA channel leak on probe error" failed to apply to 6.1-stable tree

PATCH New [email protected] 2 participants 3 messages Sep 3 – Sep 9

Subsystems (3)

Stable branch Arm i.MX and Layerscape I2C subsystem host drivers

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[email protected]

author maintainer

2026-09-03 14:58 UTC #0 lore raw

The patch below does not apply to the 6.1-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 <[email protected]>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.1.y
git checkout FETCH_HEAD
git cherry-pick -x 777979e627115734052b323d2721cdb500e81dcf
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<[email protected]>' --in-reply-to '2026090301-rope-disprove-ff1d@gregkh' --subject-prefix 'PATCH 6.1.y' 'HEAD^..'

Possible dependencies:

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 777979e627115734052b323d2721cdb500e81dcf Mon Sep 17 00:00:00 2001
From: Ruoyu Wang <[email protected]>
Date: Sat, 15 Aug 2026 23:17:20 +0800
Subject: [PATCH] i2c: mxs: fix DMA channel leak on probe error

mxs_i2c_probe() requests an exclusive DMA channel before resetting the controller and registering the I2C adapter. If either later operation fails, probe returns without releasing the channel because the remove callback is not invoked after a failed probe.

Use devm_dma_request_chan() so the device core releases the channel on probe failure and driver detach. Remove the manual release from the remove callback because the channel is now device-managed.

This issue was found by a static analysis checker and confirmed by manual source review.

Fixes 62885f59a261 ("MXS: Implement DMA support into mxs-i2c")

Assisted-by unnamed:claude-opus-4.8 typestate

Signed-off-by Ruoyu Wang <[email protected]>

Cc <[email protected]> # v3.7+

Reviewed-by Frank Li <[email protected]>

Signed-off-by Andi Shyti <[email protected]>

Link https://patch.msgid.link/[email protected] open here

drivers/i2c/busses/i2c-mxs.c +1 -4

index 4e07babea9c3..eee4fdcd9df3 100644
@@ -839,7 +839,7 @@ static int mxs_i2c_probe(struct platform_device *pdev)
 	}
 
 	/* Setup the DMA */
-	i2c->dmach = dma_request_chan(dev, "rx-tx");
+	i2c->dmach = devm_dma_request_chan(dev, "rx-tx");
 	if (IS_ERR(i2c->dmach)) {
 		return dev_err_probe(dev, PTR_ERR(i2c->dmach),
 				     "Failed to request dma\n");

@@ -877,9 +877,6 @@ static void mxs_i2c_remove(struct platform_device *pdev)
 
 	i2c_del_adapter(&i2c->adapter);
 
-	if (i2c->dmach)
-		dma_release_channel(i2c->dmach);
-
 	writel(MXS_I2C_CTRL0_SFTRST, i2c->regs + MXS_I2C_CTRL0_SET);
 }

Sasha Levin

maintainer

2026-09-09 10:54 UTC #1 lore raw

PATCH 1/2 dmaengine: Add devm_dma_request_chan()

From: Bence Csókás <[email protected]>

[ Upstream commit 08bf1663c21a3e815eda28fa242d84c945ca3b94 ]

Expand the arsenal of devm functions for DMA devices, this time for requesting channels.

Signed-off-by Bence Csókás <[email protected]>

Link https://lore.kernel.org/r/[email protected] open here

Signed-off-by Vinod Koul <[email protected]>

Stable-dep-of: 777979e62711 ("i2c: mxs: fix DMA channel leak on probe error")

Signed-off-by Sasha Levin <[email protected]>

---
 drivers/dma/dmaengine.c   | 30 ++++++++++++++++++++++++++++++
 include/linux/dmaengine.h |  7 +++++++
 2 files changed, 37 insertions(+)

drivers/dma/dmaengine.c +30 -0

index d89827d0927e4..9fb312cebe7dd 100644
@@ -927,6 +927,36 @@ void dma_release_channel(struct dma_chan *chan)
 }
 EXPORT_SYMBOL_GPL(dma_release_channel);
 
+static void dmaenginem_release_channel(void *chan)
+{
+	dma_release_channel(chan);
+}
+
+/**
+ * devm_dma_request_chan - try to allocate an exclusive slave channel
+ * @dev:	pointer to client device structure
+ * @name:	slave channel name
+ *
+ * Returns pointer to appropriate DMA channel on success or an error pointer.
+ *
+ * The operation is managed and will be undone on driver detach.
+ */
+
+struct dma_chan *devm_dma_request_chan(struct device *dev, const char *name)
+{
+	struct dma_chan *chan = dma_request_chan(dev, name);
+	int ret = 0;
+
+	if (!IS_ERR(chan))
+		ret = devm_add_action_or_reset(dev, dmaenginem_release_channel, chan);
+
+	if (ret)
+		return ERR_PTR(ret);
+
+	return chan;
+}
+EXPORT_SYMBOL_GPL(devm_dma_request_chan);
+
 /**
  * dmaengine_get - register interest in dma_channels
  */

include/linux/dmaengine.h +7 -0

index 3576c6e89fea4..368a03920c928 100644
@@ -1489,6 +1489,7 @@ struct dma_chan *__dma_request_channel(const dma_cap_mask_t *mask,
 
 struct dma_chan *dma_request_chan(struct device *dev, const char *name);
 struct dma_chan *dma_request_chan_by_mask(const dma_cap_mask_t *mask);
+struct dma_chan *devm_dma_request_chan(struct device *dev, const char *name);
 
 void dma_release_channel(struct dma_chan *chan);
 int dma_get_slave_caps(struct dma_chan *chan, struct dma_slave_caps *caps);

@@ -1525,6 +1526,12 @@ static inline struct dma_chan *dma_request_chan_by_mask(
 {
 	return ERR_PTR(-ENODEV);
 }
+
+static inline struct dma_chan *devm_dma_request_chan(struct device *dev, const char *name)
+{
+	return ERR_PTR(-ENODEV);
+}
+
 static inline void dma_release_channel(struct dma_chan *chan)
 {
 }

Signature · 1 line

2.53.0