[PATCH 0/2] staging: most: dim2: fix error handling in fsl_mx6_enable

[PATCH 0/2] staging: most: dim2: fix error handling in fsl_mx6_enable

[Artem Lytkin]

Fix error handling issues in fsl_mx6_enable() in the DIM2 driver.

Patch 1 fixes a real bug: the return value of clk_prepare_enable()
for the PLL clock is not checked, while the same call for the MLB
clock is properly checked earlier in the function.

Patch 2 addresses review feedback from Dan Carpenter on an earlier
attempt to fix this function [1]: replace IS_ERR_OR_NULL() with
IS_ERR(), use dev_err_probe() to propagate actual error codes and
handle probe deferral correctly.

[1] https://lore.kernel.org/linux-staging/ZLUnW2CrhFMBCCa1@moroto/

Artem Lytkin (2):
  staging: most: dim2: check return value of clk_prepare_enable for PLL
  staging: most: dim2: fix error handling in fsl_mx6_enable

 drivers/staging/most/dim2/dim2.c | 22 +++++++++++++---------
 1 file changed, 13 insertions(+), 9 deletions(-)

-- 
2.43.0

[PATCH 1/2] staging: most: dim2: check return value of clk_prepare_enable for PLL

[Artem Lytkin]

The return value of clk_prepare_enable() for the PLL clock is not
checked, while the same call for the MLB clock is properly checked
earlier in the function. If clk_prepare_enable() fails, the driver
continues without the PLL clock enabled, leading to undefined
hardware behavior.

Add the missing error check and disable the MLB clock on failure to
keep the cleanup consistent with the rest of the function.

Signed-off-by: Artem Lytkin <iprintercanon@gmail.com>
---
 drivers/staging/most/dim2/dim2.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/staging/most/dim2/dim2.c b/drivers/staging/most/dim2/dim2.c
index dad2abe6c..1f07c37df 100644
--- a/drivers/staging/most/dim2/dim2.c
+++ b/drivers/staging/most/dim2/dim2.c
@@ -944,7 +944,12 @@ static int fsl_mx6_enable(struct platform_device *pdev)
 		}
 
 		writel(0x888, dev->io_base + 0x38);
-		clk_prepare_enable(dev->clk_pll);
+		ret = clk_prepare_enable(dev->clk_pll);
+		if (ret) {
+			dev_err(&pdev->dev, "failed to enable pll clock\n");
+			clk_disable_unprepare(dev->clk);
+			return ret;
+		}
 	}
 
 	return 0;
-- 
2.43.0

[PATCH 2/2] staging: most: dim2: fix error handling in fsl_mx6_enable

[Artem Lytkin]

Address several error handling issues in fsl_mx6_enable():

- Replace IS_ERR_OR_NULL() with IS_ERR() for devm_clk_get() return
  value checks, since devm_clk_get() never returns NULL on error.

- Replace hardcoded -EFAULT returns with dev_err_probe() which both
  propagates the actual error code from devm_clk_get() and suppresses
  log messages during probe deferral.

- Remove an unnecessary string indirection in the clk_prepare_enable
  error message.

Signed-off-by: Artem Lytkin <iprintercanon@gmail.com>
---
 drivers/staging/most/dim2/dim2.c | 15 +++++++--------
 1 file changed, 7 insertions(+), 8 deletions(-)

diff --git a/drivers/staging/most/dim2/dim2.c b/drivers/staging/most/dim2/dim2.c
index 1f07c37df..15eaf4ff8 100644
--- a/drivers/staging/most/dim2/dim2.c
+++ b/drivers/staging/most/dim2/dim2.c
@@ -923,24 +923,23 @@ static int fsl_mx6_enable(struct platform_device *pdev)
 	int ret;
 
 	dev->clk = devm_clk_get(&pdev->dev, "mlb");
-	if (IS_ERR_OR_NULL(dev->clk)) {
-		dev_err(&pdev->dev, "unable to get mlb clock\n");
-		return -EFAULT;
-	}
+	if (IS_ERR(dev->clk))
+		return dev_err_probe(&pdev->dev, PTR_ERR(dev->clk),
+				     "unable to get mlb clock\n");
 
 	ret = clk_prepare_enable(dev->clk);
 	if (ret) {
-		dev_err(&pdev->dev, "%s\n", "clk_prepare_enable failed");
+		dev_err(&pdev->dev, "clk_prepare_enable failed\n");
 		return ret;
 	}
 
 	if (dev->clk_speed >= CLK_2048FS) {
 		/* enable pll */
 		dev->clk_pll = devm_clk_get(&pdev->dev, "pll8_mlb");
-		if (IS_ERR_OR_NULL(dev->clk_pll)) {
-			dev_err(&pdev->dev, "unable to get mlb pll clock\n");
+		if (IS_ERR(dev->clk_pll)) {
 			clk_disable_unprepare(dev->clk);
-			return -EFAULT;
+			return dev_err_probe(&pdev->dev, PTR_ERR(dev->clk_pll),
+					     "unable to get mlb pll clock\n");
 		}
 
 		writel(0x888, dev->io_base + 0x38);
-- 
2.43.0

Re: [PATCH 2/2] staging: most: dim2: fix error handling in fsl_mx6_enable

[Dan Carpenter]

On Mon, Feb 16, 2026 at 08:19:21PM +0000, Artem Lytkin wrote:
> Address several error handling issues in fsl_mx6_enable():
> 
> - Replace IS_ERR_OR_NULL() with IS_ERR() for devm_clk_get() return
>   value checks, since devm_clk_get() never returns NULL on error.
> 
> - Replace hardcoded -EFAULT returns with dev_err_probe() which both
>   propagates the actual error code from devm_clk_get() and suppresses
>   log messages during probe deferral.
> 
> - Remove an unnecessary string indirection in the clk_prepare_enable
>   error message.
> 

Some of these are unrelated things.

regards,
dan carpenter

[PATCH v2 0/3] staging: most: dim2: clean up error handling in fsl_mx6_enable

[Artem Lytkin]

This series cleans up error handling in fsl_mx6_enable(), split into
separate logical changes per Dan Carpenter's review of v1.

Changes since v1:
  - Split combined patch into 3 separate patches (one change per patch)
  - Extended string indirection fix to all three enable functions

Patch 1 replaces IS_ERR_OR_NULL() with IS_ERR() since devm_clk_get()
never returns NULL.

Patch 2 replaces dev_err() + hardcoded -EFAULT with dev_err_probe()
and PTR_ERR() to propagate correct error codes and handle probe
deferral properly.

Patch 3 removes unnecessary string indirection in dev_err() calls
("%s\n", "message" -> "message\n").

Artem Lytkin (3):
  staging: most: dim2: replace IS_ERR_OR_NULL with IS_ERR for
    devm_clk_get
  staging: most: dim2: use dev_err_probe and proper error codes for
    clock
  staging: most: dim2: remove unnecessary string indirection in dev_err

 drivers/staging/most/dim2/dim2.c | 19 +++++++++----------
 1 file changed, 9 insertions(+), 10 deletions(-)

-- 
2.43.0

[PATCH v2 1/3] staging: most: dim2: replace IS_ERR_OR_NULL with IS_ERR for devm_clk_get

[Artem Lytkin]

devm_clk_get() never returns NULL, so IS_ERR_OR_NULL() checks are
unnecessary. Replace them with IS_ERR() for both the "mlb" and
"pll8_mlb" clock lookups in fsl_mx6_enable().

Signed-off-by: Artem Lytkin <iprintercanon@gmail.com>
---
 drivers/staging/most/dim2/dim2.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/staging/most/dim2/dim2.c b/drivers/staging/most/dim2/dim2.c
index 92c7a7d8fe7e..cea1ba99caf7 100644
--- a/drivers/staging/most/dim2/dim2.c
+++ b/drivers/staging/most/dim2/dim2.c
@@ -921,7 +921,7 @@ static int fsl_mx6_enable(struct platform_device *pdev)
 	int ret;
 
 	dev->clk = devm_clk_get(&pdev->dev, "mlb");
-	if (IS_ERR_OR_NULL(dev->clk)) {
+	if (IS_ERR(dev->clk)) {
 		dev_err(&pdev->dev, "unable to get mlb clock\n");
 		return -EFAULT;
 	}
@@ -935,7 +935,7 @@ static int fsl_mx6_enable(struct platform_device *pdev)
 	if (dev->clk_speed >= CLK_2048FS) {
 		/* enable pll */
 		dev->clk_pll = devm_clk_get(&pdev->dev, "pll8_mlb");
-		if (IS_ERR_OR_NULL(dev->clk_pll)) {
+		if (IS_ERR(dev->clk_pll)) {
 			dev_err(&pdev->dev, "unable to get mlb pll clock\n");
 			clk_disable_unprepare(dev->clk);
 			return -EFAULT;
-- 
2.43.0

[PATCH v2 2/3] staging: most: dim2: use dev_err_probe and proper error codes for clock

[Artem Lytkin]

Replace hardcoded -EFAULT returns with dev_err_probe() and PTR_ERR()
when devm_clk_get() fails in fsl_mx6_enable(). This ensures the
correct error code is propagated (e.g. -EPROBE_DEFER for deferred
probing) and avoids log noise during probe deferral.

Signed-off-by: Artem Lytkin <iprintercanon@gmail.com>
---
 drivers/staging/most/dim2/dim2.c | 11 +++++------
 1 file changed, 5 insertions(+), 6 deletions(-)

diff --git a/drivers/staging/most/dim2/dim2.c b/drivers/staging/most/dim2/dim2.c
index cea1ba99caf7..e4c8b4995c61 100644
--- a/drivers/staging/most/dim2/dim2.c
+++ b/drivers/staging/most/dim2/dim2.c
@@ -921,10 +921,9 @@ static int fsl_mx6_enable(struct platform_device *pdev)
 	int ret;
 
 	dev->clk = devm_clk_get(&pdev->dev, "mlb");
-	if (IS_ERR(dev->clk)) {
-		dev_err(&pdev->dev, "unable to get mlb clock\n");
-		return -EFAULT;
-	}
+	if (IS_ERR(dev->clk))
+		return dev_err_probe(&pdev->dev, PTR_ERR(dev->clk),
+				     "unable to get mlb clock\n");
 
 	ret = clk_prepare_enable(dev->clk);
 	if (ret) {
@@ -936,9 +935,9 @@ static int fsl_mx6_enable(struct platform_device *pdev)
 		/* enable pll */
 		dev->clk_pll = devm_clk_get(&pdev->dev, "pll8_mlb");
 		if (IS_ERR(dev->clk_pll)) {
-			dev_err(&pdev->dev, "unable to get mlb pll clock\n");
 			clk_disable_unprepare(dev->clk);
-			return -EFAULT;
+			return dev_err_probe(&pdev->dev, PTR_ERR(dev->clk_pll),
+					     "unable to get mlb pll clock\n");
 		}
 
 		writel(0x888, dev->io_base + 0x38);
-- 
2.43.0

[PATCH v2 3/3] staging: most: dim2: remove unnecessary string indirection in dev_err

[Artem Lytkin]

Replace dev_err(&pdev->dev, "%s\n", "clk_prepare_enable failed") with
the direct format string dev_err(&pdev->dev, "clk_prepare_enable
failed\n"). The extra level of indirection through %s is unnecessary.

Signed-off-by: Artem Lytkin <iprintercanon@gmail.com>
---
 drivers/staging/most/dim2/dim2.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/staging/most/dim2/dim2.c b/drivers/staging/most/dim2/dim2.c
index e4c8b4995c61..66617e89e028 100644
--- a/drivers/staging/most/dim2/dim2.c
+++ b/drivers/staging/most/dim2/dim2.c
@@ -927,7 +927,7 @@ static int fsl_mx6_enable(struct platform_device *pdev)
 
 	ret = clk_prepare_enable(dev->clk);
 	if (ret) {
-		dev_err(&pdev->dev, "%s\n", "clk_prepare_enable failed");
+		dev_err(&pdev->dev, "clk_prepare_enable failed\n");
 		return ret;
 	}
 
@@ -975,7 +975,7 @@ static int rcar_gen2_enable(struct platform_device *pdev)
 
 	ret = clk_prepare_enable(dev->clk);
 	if (ret) {
-		dev_err(&pdev->dev, "%s\n", "clk_prepare_enable failed");
+		dev_err(&pdev->dev, "clk_prepare_enable failed\n");
 		return ret;
 	}
 
@@ -1020,7 +1020,7 @@ static int rcar_gen3_enable(struct platform_device *pdev)
 
 	ret = clk_prepare_enable(dev->clk);
 	if (ret) {
-		dev_err(&pdev->dev, "%s\n", "clk_prepare_enable failed");
+		dev_err(&pdev->dev, "clk_prepare_enable failed\n");
 		return ret;
 	}
 
-- 
2.43.0

[PATCH v2 0/3] staging: most: dim2: clean up error handling in fsl_mx6_enable

[Artem Lytkin]

This series cleans up error handling in fsl_mx6_enable(), split into
separate logical changes per Dan Carpenter's review of v1.

Changes since v1:
  - Split combined patch into 3 separate patches (one change per patch)
  - Extended string indirection fix to all three enable functions

Patch 1 replaces IS_ERR_OR_NULL() with IS_ERR() since devm_clk_get()
never returns NULL.

Patch 2 replaces dev_err() + hardcoded -EFAULT with dev_err_probe()
and PTR_ERR() to propagate correct error codes and handle probe
deferral properly.

Patch 3 removes unnecessary string indirection in dev_err() calls
("%s\n", "message" -> "message\n").

Artem Lytkin (3):
  staging: most: dim2: replace IS_ERR_OR_NULL with IS_ERR for
    devm_clk_get
  staging: most: dim2: use dev_err_probe and proper error codes for
    clock
  staging: most: dim2: remove unnecessary string indirection in dev_err

 drivers/staging/most/dim2/dim2.c | 19 +++++++++----------
 1 file changed, 9 insertions(+), 10 deletions(-)

-- 
2.43.0

[PATCH v2 1/3] staging: most: dim2: replace IS_ERR_OR_NULL with IS_ERR for devm_clk_get

[Artem Lytkin]

devm_clk_get() never returns NULL, so IS_ERR_OR_NULL() checks are
unnecessary. Replace them with IS_ERR() for both the "mlb" and
"pll8_mlb" clock lookups in fsl_mx6_enable().

Signed-off-by: Artem Lytkin <iprintercanon@gmail.com>
---
 drivers/staging/most/dim2/dim2.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/staging/most/dim2/dim2.c b/drivers/staging/most/dim2/dim2.c
index 92c7a7d8fe7e..cea1ba99caf7 100644
--- a/drivers/staging/most/dim2/dim2.c
+++ b/drivers/staging/most/dim2/dim2.c
@@ -921,7 +921,7 @@ static int fsl_mx6_enable(struct platform_device *pdev)
 	int ret;
 
 	dev->clk = devm_clk_get(&pdev->dev, "mlb");
-	if (IS_ERR_OR_NULL(dev->clk)) {
+	if (IS_ERR(dev->clk)) {
 		dev_err(&pdev->dev, "unable to get mlb clock\n");
 		return -EFAULT;
 	}
@@ -935,7 +935,7 @@ static int fsl_mx6_enable(struct platform_device *pdev)
 	if (dev->clk_speed >= CLK_2048FS) {
 		/* enable pll */
 		dev->clk_pll = devm_clk_get(&pdev->dev, "pll8_mlb");
-		if (IS_ERR_OR_NULL(dev->clk_pll)) {
+		if (IS_ERR(dev->clk_pll)) {
 			dev_err(&pdev->dev, "unable to get mlb pll clock\n");
 			clk_disable_unprepare(dev->clk);
 			return -EFAULT;
-- 
2.43.0

[PATCH v2 2/3] staging: most: dim2: use dev_err_probe and proper error codes for clock

[Artem Lytkin]

Replace hardcoded -EFAULT returns with dev_err_probe() and PTR_ERR()
when devm_clk_get() fails in fsl_mx6_enable(). This ensures the
correct error code is propagated (e.g. -EPROBE_DEFER for deferred
probing) and avoids log noise during probe deferral.

Signed-off-by: Artem Lytkin <iprintercanon@gmail.com>
---
 drivers/staging/most/dim2/dim2.c | 11 +++++------
 1 file changed, 5 insertions(+), 6 deletions(-)

diff --git a/drivers/staging/most/dim2/dim2.c b/drivers/staging/most/dim2/dim2.c
index cea1ba99caf7..e4c8b4995c61 100644
--- a/drivers/staging/most/dim2/dim2.c
+++ b/drivers/staging/most/dim2/dim2.c
@@ -921,10 +921,9 @@ static int fsl_mx6_enable(struct platform_device *pdev)
 	int ret;
 
 	dev->clk = devm_clk_get(&pdev->dev, "mlb");
-	if (IS_ERR(dev->clk)) {
-		dev_err(&pdev->dev, "unable to get mlb clock\n");
-		return -EFAULT;
-	}
+	if (IS_ERR(dev->clk))
+		return dev_err_probe(&pdev->dev, PTR_ERR(dev->clk),
+				     "unable to get mlb clock\n");
 
 	ret = clk_prepare_enable(dev->clk);
 	if (ret) {
@@ -936,9 +935,9 @@ static int fsl_mx6_enable(struct platform_device *pdev)
 		/* enable pll */
 		dev->clk_pll = devm_clk_get(&pdev->dev, "pll8_mlb");
 		if (IS_ERR(dev->clk_pll)) {
-			dev_err(&pdev->dev, "unable to get mlb pll clock\n");
 			clk_disable_unprepare(dev->clk);
-			return -EFAULT;
+			return dev_err_probe(&pdev->dev, PTR_ERR(dev->clk_pll),
+					     "unable to get mlb pll clock\n");
 		}
 
 		writel(0x888, dev->io_base + 0x38);
-- 
2.43.0

[PATCH v2 3/3] staging: most: dim2: remove unnecessary string indirection in dev_err

[Artem Lytkin]

Replace dev_err(&pdev->dev, "%s\n", "clk_prepare_enable failed") with
the direct format string dev_err(&pdev->dev, "clk_prepare_enable
failed\n"). The extra level of indirection through %s is unnecessary.

Signed-off-by: Artem Lytkin <iprintercanon@gmail.com>
---
 drivers/staging/most/dim2/dim2.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/staging/most/dim2/dim2.c b/drivers/staging/most/dim2/dim2.c
index e4c8b4995c61..66617e89e028 100644
--- a/drivers/staging/most/dim2/dim2.c
+++ b/drivers/staging/most/dim2/dim2.c
@@ -927,7 +927,7 @@ static int fsl_mx6_enable(struct platform_device *pdev)
 
 	ret = clk_prepare_enable(dev->clk);
 	if (ret) {
-		dev_err(&pdev->dev, "%s\n", "clk_prepare_enable failed");
+		dev_err(&pdev->dev, "clk_prepare_enable failed\n");
 		return ret;
 	}
 
@@ -975,7 +975,7 @@ static int rcar_gen2_enable(struct platform_device *pdev)
 
 	ret = clk_prepare_enable(dev->clk);
 	if (ret) {
-		dev_err(&pdev->dev, "%s\n", "clk_prepare_enable failed");
+		dev_err(&pdev->dev, "clk_prepare_enable failed\n");
 		return ret;
 	}
 
@@ -1020,7 +1020,7 @@ static int rcar_gen3_enable(struct platform_device *pdev)
 
 	ret = clk_prepare_enable(dev->clk);
 	if (ret) {
-		dev_err(&pdev->dev, "%s\n", "clk_prepare_enable failed");
+		dev_err(&pdev->dev, "clk_prepare_enable failed\n");
 		return ret;
 	}
 
-- 
2.43.0

Re: [PATCH v2 0/3] staging: most: dim2: clean up error handling in fsl_mx6_enable

[Greg Kroah-Hartman]

On Tue, Feb 24, 2026 at 04:37:20AM +0000, Artem Lytkin wrote:
> This series cleans up error handling in fsl_mx6_enable(), split into
> separate logical changes per Dan Carpenter's review of v1.
> 
> Changes since v1:
>   - Split combined patch into 3 separate patches (one change per patch)
>   - Extended string indirection fix to all three enable functions
> 
> Patch 1 replaces IS_ERR_OR_NULL() with IS_ERR() since devm_clk_get()
> never returns NULL.
> 
> Patch 2 replaces dev_err() + hardcoded -EFAULT with dev_err_probe()
> and PTR_ERR() to propagate correct error codes and handle probe
> deferral properly.
> 
> Patch 3 removes unnecessary string indirection in dev_err() calls
> ("%s\n", "message" -> "message\n").
> 
> Artem Lytkin (3):
>   staging: most: dim2: replace IS_ERR_OR_NULL with IS_ERR for
>     devm_clk_get
>   staging: most: dim2: use dev_err_probe and proper error codes for
>     clock
>   staging: most: dim2: remove unnecessary string indirection in dev_err
> 
>  drivers/staging/most/dim2/dim2.c | 19 +++++++++----------
>  1 file changed, 9 insertions(+), 10 deletions(-)
> 
> -- 
> 2.43.0
> 

I see 2 different copies of this series, as can be seen on
lore.kernel.org:
	https://lore.kernel.org/all/20260224043723.1828-1-iprintercanon@gmail.com/

which is "correct"?

Can you send a v3 so I know what to do?

thanks,

greg k-h