[PATCH] staging: sm750fb: use proper error codes instead of -1

[PATCH] staging: sm750fb: use proper error codes instead of -1

[Soham Kute]

Replace magic return value -1 with proper kernel error
codes -EBUSY, -ETIMEDOUT and -EINVAL.

Signed-off-by: Soham Kute <officialsohamkute@gmail.com>
---
 drivers/staging/sm750fb/ddk750_swi2c.c | 4 ++--
 drivers/staging/sm750fb/sm750_accel.c  | 6 +++---
 drivers/staging/sm750fb/sm750_hw.c     | 4 ++--
 3 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/drivers/staging/sm750fb/ddk750_swi2c.c b/drivers/staging/sm750fb/ddk750_swi2c.c
index 0ef8d4ff2ef9..d90a93ab8fdc 100644
--- a/drivers/staging/sm750fb/ddk750_swi2c.c
+++ b/drivers/staging/sm750fb/ddk750_swi2c.c
@@ -294,7 +294,7 @@ static long sw_i2c_write_byte(unsigned char data)
 	if (i < 0xff)
 		return 0;
 	else
-		return -1;
+		return -ETIMEDOUT;
 }
 
 /*
@@ -394,7 +394,7 @@ long sm750_sw_i2c_init(unsigned char clk_gpio, unsigned char data_gpio)
 	 * range is only from [0..63]
 	 */
 	if ((clk_gpio > 31) || (data_gpio > 31))
-		return -1;
+		return -EINVAL;
 
 	if (sm750_get_chip_type() == SM750LE)
 		return sm750le_i2c_init(clk_gpio, data_gpio);
diff --git a/drivers/staging/sm750fb/sm750_accel.c b/drivers/staging/sm750fb/sm750_accel.c
index 046b9282b24a..fa593d4f31fe 100644
--- a/drivers/staging/sm750fb/sm750_accel.c
+++ b/drivers/staging/sm750fb/sm750_accel.c
@@ -97,7 +97,7 @@ int sm750_hw_fillrect(struct lynx_accel *accel,
 		 * got something error
 		 */
 		pr_debug("De engine always busy\n");
-		return -1;
+		return -EBUSY;
 	}
 
 	write_dpr(accel, DE_WINDOW_DESTINATION_BASE, base); /* dpr40 */
@@ -264,7 +264,7 @@ int sm750_hw_copyarea(struct lynx_accel *accel,
 		  (sPitch / Bpp & DE_WINDOW_WIDTH_SRC_MASK)); /* dpr3c */
 
 	if (accel->de_wait() != 0)
-		return -1;
+		return -EBUSY;
 
 	write_dpr(accel, DE_SOURCE,
 		  ((sx << DE_SOURCE_X_K1_SHIFT) & DE_SOURCE_X_K1_MASK) |
@@ -333,7 +333,7 @@ int sm750_hw_imageblit(struct lynx_accel *accel, const char *pSrcbuf,
 	ulBytesRemain = ulBytesPerScan & 3;
 
 	if (accel->de_wait() != 0)
-		return -1;
+		return -EBUSY;
 
 	/*
 	 * 2D Source Base.
diff --git a/drivers/staging/sm750fb/sm750_hw.c b/drivers/staging/sm750fb/sm750_hw.c
index ce46f240cbaf..e4b6b254335e 100644
--- a/drivers/staging/sm750fb/sm750_hw.c
+++ b/drivers/staging/sm750fb/sm750_hw.c
@@ -518,7 +518,7 @@ int hw_sm750le_de_wait(void)
 			return 0;
 	}
 	/* timeout error */
-	return -1;
+	return -ETIMEDOUT;
 }
 
 int hw_sm750_de_wait(void)
@@ -536,7 +536,7 @@ int hw_sm750_de_wait(void)
 			return 0;
 	}
 	/* timeout error */
-	return -1;
+	return -ETIMEDOUT;
 }
 
 int hw_sm750_pan_display(struct lynxfb_crtc *crtc,
-- 
2.34.1

Re: [PATCH] staging: sm750fb: use proper error codes instead of -1

[Dan Carpenter]

On Sun, Mar 01, 2026 at 10:44:34AM +0530, Soham Kute wrote:
> diff --git a/drivers/staging/sm750fb/ddk750_swi2c.c b/drivers/staging/sm750fb/ddk750_swi2c.c
> index 0ef8d4ff2ef9..d90a93ab8fdc 100644
> --- a/drivers/staging/sm750fb/ddk750_swi2c.c
> +++ b/drivers/staging/sm750fb/ddk750_swi2c.c
> @@ -294,7 +294,7 @@ static long sw_i2c_write_byte(unsigned char data)
>  	if (i < 0xff)
>  		return 0;
>  	else
> -		return -1;
> +		return -ETIMEDOUT;

The comment still says this returns -1.

Actually could you do this one function at a time, and in each commit
message please say "The callers propogate the error code back" or "
None of the callers check the error code" or "The callers treat all
non-zero error codes as failure and return -EINVAL" or whatever.


> @@ -264,7 +264,7 @@ int sm750_hw_copyarea(struct lynx_accel *accel,
>  		  (sPitch / Bpp & DE_WINDOW_WIDTH_SRC_MASK)); /* dpr3c */
>  
>  	if (accel->de_wait() != 0)

Did you consider propagating the error code from accel->de_wait()
instead?  That feels like a better solution but I haven't looked at
it at all.

regards,
dan carpenter

[PATCH v2 0/6] staging: sm750fb: fix error return values

[Soham Kute]

This is v2 of the sm750fb error code fixes, split into one patch
per function as requested by Dan Carpenter.

Changes in v2:
- Split into one patch per function
- Propagate de_wait() error instead of hardcoding -EBUSY
- Each commit message describes caller behavior

Soham Kute (6):
11ca38f0ec63 staging: sm750fb: hw_sm750le_de_wait: return -ETIMEDOUT on timeout
28df828cc89b staging: sm750fb: sm750_hw_fillrect: propagate de_wait() error
2378ece78154 staging: sm750fb: sm750_hw_copyarea: propagate de_wait() error
85139ac8c7fe staging: sm750fb: sm750_hw_imageblit: propagate de_wait() error
9c2430311e23 staging: sm750fb: sw_i2c_write_byte: return -ETIMEDOUT on timeout
915599b01e9b staging: sm750fb: sm750_sw_i2c_init: return -EINVAL for invalid GPIO

[PATCH 1/6] staging: sm750fb: hw_sm750le_de_wait: return -ETIMEDOUT on timeout

[Soham Kute]

Return -ETIMEDOUT instead of -1 when the DE engine poll loop
times out. The callers check for non-zero return value and
propagate the error code back to their callers.

Signed-off-by: Soham Kute <officialsohamkute@gmail.com>
---
 drivers/staging/sm750fb/sm750_hw.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/staging/sm750fb/sm750_hw.c b/drivers/staging/sm750fb/sm750_hw.c
index ce46f240cbaf..e4b6b254335e 100644
--- a/drivers/staging/sm750fb/sm750_hw.c
+++ b/drivers/staging/sm750fb/sm750_hw.c
@@ -518,7 +518,7 @@ int hw_sm750le_de_wait(void)
 			return 0;
 	}
 	/* timeout error */
-	return -1;
+	return -ETIMEDOUT;
 }
 
 int hw_sm750_de_wait(void)
@@ -536,7 +536,7 @@ int hw_sm750_de_wait(void)
 			return 0;
 	}
 	/* timeout error */
-	return -1;
+	return -ETIMEDOUT;
 }
 
 int hw_sm750_pan_display(struct lynxfb_crtc *crtc,
-- 
2.34.1

[PATCH 2/6] staging: sm750fb: sm750_hw_fillrect: propagate de_wait() error

[Soham Kute]

Propagate the error from accel->de_wait() instead of returning -1.
The caller treats all non-zero return values as failure.

Signed-off-by: Soham Kute <officialsohamkute@gmail.com>
---
 drivers/staging/sm750fb/sm750_accel.c | 10 ++++------
 1 file changed, 4 insertions(+), 6 deletions(-)

diff --git a/drivers/staging/sm750fb/sm750_accel.c b/drivers/staging/sm750fb/sm750_accel.c
index 046b9282b24a..1bd0502db039 100644
--- a/drivers/staging/sm750fb/sm750_accel.c
+++ b/drivers/staging/sm750fb/sm750_accel.c
@@ -90,14 +90,12 @@ int sm750_hw_fillrect(struct lynx_accel *accel,
 		      u32 color, u32 rop)
 {
 	u32 de_ctrl;
+	int ret;
 
-	if (accel->de_wait() != 0) {
-		/*
-		 * int time wait and always busy,seems hardware
-		 * got something error
-		 */
+	ret = accel->de_wait();
+	if (ret) {
 		pr_debug("De engine always busy\n");
-		return -1;
+		return ret;
 	}
 
 	write_dpr(accel, DE_WINDOW_DESTINATION_BASE, base); /* dpr40 */
-- 
2.34.1

[PATCH 3/6] staging: sm750fb: sm750_hw_copyarea: propagate de_wait() error

[Soham Kute]

Propagate the error from accel->de_wait() instead of returning -1.
The caller treats all non-zero return values as failure.

Signed-off-by: Soham Kute <officialsohamkute@gmail.com>
---
 drivers/staging/sm750fb/sm750_accel.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/staging/sm750fb/sm750_accel.c b/drivers/staging/sm750fb/sm750_accel.c
index 1bd0502db039..f2fde011e7ca 100644
--- a/drivers/staging/sm750fb/sm750_accel.c
+++ b/drivers/staging/sm750fb/sm750_accel.c
@@ -152,6 +152,7 @@ int sm750_hw_copyarea(struct lynx_accel *accel,
 		      unsigned int rop2)
 {
 	unsigned int nDirection, de_ctrl;
+	int ret;
 
 	nDirection = LEFT_TO_RIGHT;
 	/* Direction of ROP2 operation: 1 = Left to Right, (-1) = Right to Left */
@@ -261,8 +262,9 @@ int sm750_hw_copyarea(struct lynx_accel *accel,
 		   DE_WINDOW_WIDTH_DST_MASK) |
 		  (sPitch / Bpp & DE_WINDOW_WIDTH_SRC_MASK)); /* dpr3c */
 
-	if (accel->de_wait() != 0)
-		return -1;
+	ret = accel->de_wait();
+	if (ret)
+		return ret;
 
 	write_dpr(accel, DE_SOURCE,
 		  ((sx << DE_SOURCE_X_K1_SHIFT) & DE_SOURCE_X_K1_MASK) |
-- 
2.34.1

Re: [PATCH 3/6] staging: sm750fb: sm750_hw_copyarea: propagate de_wait() error

[Dan Carpenter]

On Wed, Mar 04, 2026 at 02:15:42PM +0530, Soham Kute wrote:
> Propagate the error from accel->de_wait() instead of returning -1.
> The caller treats all non-zero return values as failure.
> 

The caller just ignores errors.

regards,
dan carpenter

[PATCH 4/6] staging: sm750fb: sm750_hw_imageblit: propagate de_wait() error

[Soham Kute]

Propagate the error from accel->de_wait() instead of returning -1.
The caller treats all non-zero return values as failure.

Signed-off-by: Soham Kute <officialsohamkute@gmail.com>
---
 drivers/staging/sm750fb/sm750_accel.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/staging/sm750fb/sm750_accel.c b/drivers/staging/sm750fb/sm750_accel.c
index f2fde011e7ca..7d11810864ae 100644
--- a/drivers/staging/sm750fb/sm750_accel.c
+++ b/drivers/staging/sm750fb/sm750_accel.c
@@ -325,15 +325,16 @@ int sm750_hw_imageblit(struct lynx_accel *accel, const char *pSrcbuf,
 	unsigned int ulBytesRemain;
 	unsigned int de_ctrl = 0;
 	unsigned char ajRemain[4];
-	int i, j;
+	int i, j, ret;
 
 	startBit &= 7; /* Just make sure the start bit is within legal range */
 	ulBytesPerScan = (width + startBit + 7) / 8;
 	ul4BytesPerScan = ulBytesPerScan & ~3;
 	ulBytesRemain = ulBytesPerScan & 3;
 
-	if (accel->de_wait() != 0)
-		return -1;
+	ret = accel->de_wait();
+	if (ret)
+		return ret;
 
 	/*
 	 * 2D Source Base.
-- 
2.34.1

Re: [PATCH 4/6] staging: sm750fb: sm750_hw_imageblit: propagate de_wait() error

[Dan Carpenter]

On Wed, Mar 04, 2026 at 02:15:43PM +0530, Soham Kute wrote:
> Propagate the error from accel->de_wait() instead of returning -1.
> The caller treats all non-zero return values as failure.

The caller ignores errors.

regards,
dan carpenter

[PATCH 5/6] staging: sm750fb: sw_i2c_write_byte: return -ETIMEDOUT on timeout

[Soham Kute]

Return -ETIMEDOUT instead of -1 when the I2C byte write times out.
The callers check for non-zero return value and treat it as failure.

Signed-off-by: Soham Kute <officialsohamkute@gmail.com>
---
 drivers/staging/sm750fb/ddk750_swi2c.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/staging/sm750fb/ddk750_swi2c.c b/drivers/staging/sm750fb/ddk750_swi2c.c
index 0ef8d4ff2ef9..a17f758dda6c 100644
--- a/drivers/staging/sm750fb/ddk750_swi2c.c
+++ b/drivers/staging/sm750fb/ddk750_swi2c.c
@@ -294,7 +294,7 @@ static long sw_i2c_write_byte(unsigned char data)
 	if (i < 0xff)
 		return 0;
 	else
-		return -1;
+		return -ETIMEDOUT;
 }
 
 /*
-- 
2.34.1

Re: [PATCH 5/6] staging: sm750fb: sw_i2c_write_byte: return -ETIMEDOUT on timeout

[Dan Carpenter]

On Wed, Mar 04, 2026 at 02:15:44PM +0530, Soham Kute wrote:
> Return -ETIMEDOUT instead of -1 when the I2C byte write times out.
> The callers check for non-zero return value and treat it as failure.
> 

"The callers either ignore errors or treat all non-zero returns as
failure and return -1."

> Signed-off-by: Soham Kute <officialsohamkute@gmail.com>
> ---
>  drivers/staging/sm750fb/ddk750_swi2c.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/staging/sm750fb/ddk750_swi2c.c b/drivers/staging/sm750fb/ddk750_swi2c.c
> index 0ef8d4ff2ef9..a17f758dda6c 100644
> --- a/drivers/staging/sm750fb/ddk750_swi2c.c
> +++ b/drivers/staging/sm750fb/ddk750_swi2c.c
> @@ -294,7 +294,7 @@ static long sw_i2c_write_byte(unsigned char data)


Need to update the comments at the start of the function as well.

   234  /*
   235   *  This function writes one byte to the slave device
   236   *
   237   *  Parameters:
   238   *      data    - Data to be write to the slave device
   239   *
   240   *  Return Value:
   241   *       0   - Success
   242   *      -1   - Fail to write byte
                ^^^^^^^^^^^^^^^^^^^^^^^^^
   243   */
   244  static long sw_i2c_write_byte(unsigned char data)

>  	if (i < 0xff)
>  		return 0;
>  	else
> -		return -1;
> +		return -ETIMEDOUT;

I don't think -ETIMEDOUT is the correct error code.  Maybe -EIO or
-EINVAL.

regards,
dan carpenter

[PATCH 6/6] staging: sm750fb: sm750_sw_i2c_init: return -EINVAL for invalid GPIO

[Soham Kute]

Return -EINVAL instead of -1 when the GPIO pin number is out of
range. The caller checks for non-zero return value as failure.

Signed-off-by: Soham Kute <officialsohamkute@gmail.com>
---
 drivers/staging/sm750fb/ddk750_swi2c.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/staging/sm750fb/ddk750_swi2c.c b/drivers/staging/sm750fb/ddk750_swi2c.c
index a17f758dda6c..d90a93ab8fdc 100644
--- a/drivers/staging/sm750fb/ddk750_swi2c.c
+++ b/drivers/staging/sm750fb/ddk750_swi2c.c
@@ -394,7 +394,7 @@ long sm750_sw_i2c_init(unsigned char clk_gpio, unsigned char data_gpio)
 	 * range is only from [0..63]
 	 */
 	if ((clk_gpio > 31) || (data_gpio > 31))
-		return -1;
+		return -EINVAL;
 
 	if (sm750_get_chip_type() == SM750LE)
 		return sm750le_i2c_init(clk_gpio, data_gpio);
-- 
2.34.1

Re: [PATCH 6/6] staging: sm750fb: sm750_sw_i2c_init: return -EINVAL for invalid GPIO

[Dan Carpenter]

On Wed, Mar 04, 2026 at 02:15:45PM +0530, Soham Kute wrote:
> Return -EINVAL instead of -1 when the GPIO pin number is out of
> range. The caller checks for non-zero return value as failure.
> 

The caller ignores errors.

> Signed-off-by: Soham Kute <officialsohamkute@gmail.com>
> ---
>  drivers/staging/sm750fb/ddk750_swi2c.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/staging/sm750fb/ddk750_swi2c.c b/drivers/staging/sm750fb/ddk750_swi2c.c
> index a17f758dda6c..d90a93ab8fdc 100644
> --- a/drivers/staging/sm750fb/ddk750_swi2c.c
> +++ b/drivers/staging/sm750fb/ddk750_swi2c.c
> @@ -394,7 +394,7 @@ long sm750_sw_i2c_init(unsigned char clk_gpio, unsigned char data_gpio)
>  	 * range is only from [0..63]
>  	 */
>  	if ((clk_gpio > 31) || (data_gpio > 31))
> -		return -1;
> +		return -EINVAL;

Need to update the comments for the function.

regards,
dan carpenter

>  
>  	if (sm750_get_chip_type() == SM750LE)
>  		return sm750le_i2c_init(clk_gpio, data_gpio);
> -- 
> 2.34.1

[PATCH 1/6] staging: sm750fb: hw_sm750le_de_wait: return -ETIMEDOUT on timeout

[Soham Kute]

Return -ETIMEDOUT instead of -1 when the DE engine poll loop
times out. The callers check for non-zero return value and
propagate the error code back to their callers.

Signed-off-by: Soham Kute <officialsohamkute@gmail.com>
---
 drivers/staging/sm750fb/sm750_hw.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/staging/sm750fb/sm750_hw.c b/drivers/staging/sm750fb/sm750_hw.c
index ce46f240cbaf..e4b6b254335e 100644
--- a/drivers/staging/sm750fb/sm750_hw.c
+++ b/drivers/staging/sm750fb/sm750_hw.c
@@ -518,7 +518,7 @@ int hw_sm750le_de_wait(void)
 			return 0;
 	}
 	/* timeout error */
-	return -1;
+	return -ETIMEDOUT;
 }
 
 int hw_sm750_de_wait(void)
@@ -536,7 +536,7 @@ int hw_sm750_de_wait(void)
 			return 0;
 	}
 	/* timeout error */
-	return -1;
+	return -ETIMEDOUT;
 }
 
 int hw_sm750_pan_display(struct lynxfb_crtc *crtc,
-- 
2.34.1

[PATCH 2/6] staging: sm750fb: sm750_hw_fillrect: propagate de_wait() error

[Soham Kute]

Propagate the error from accel->de_wait() instead of returning -1.
The caller treats all non-zero return values as failure.

Signed-off-by: Soham Kute <officialsohamkute@gmail.com>
---
 drivers/staging/sm750fb/sm750_accel.c | 10 ++++------
 1 file changed, 4 insertions(+), 6 deletions(-)

diff --git a/drivers/staging/sm750fb/sm750_accel.c b/drivers/staging/sm750fb/sm750_accel.c
index 046b9282b24a..1bd0502db039 100644
--- a/drivers/staging/sm750fb/sm750_accel.c
+++ b/drivers/staging/sm750fb/sm750_accel.c
@@ -90,14 +90,12 @@ int sm750_hw_fillrect(struct lynx_accel *accel,
 		      u32 color, u32 rop)
 {
 	u32 de_ctrl;
+	int ret;
 
-	if (accel->de_wait() != 0) {
-		/*
-		 * int time wait and always busy,seems hardware
-		 * got something error
-		 */
+	ret = accel->de_wait();
+	if (ret) {
 		pr_debug("De engine always busy\n");
-		return -1;
+		return ret;
 	}
 
 	write_dpr(accel, DE_WINDOW_DESTINATION_BASE, base); /* dpr40 */
-- 
2.34.1

Re: [PATCH 2/6] staging: sm750fb: sm750_hw_fillrect: propagate de_wait() error

[Dan Carpenter]

On Wed, Mar 04, 2026 at 11:05:25PM +0530, Soham Kute wrote:
> Propagate the error from accel->de_wait() instead of returning -1.
> The caller treats all non-zero return values as failure.

No, the caller just ignores the errors.

regards,
dan carpenter

[PATCH 3/6] staging: sm750fb: sm750_hw_copyarea: propagate de_wait() error

[Soham Kute]

Propagate the error from accel->de_wait() instead of returning -1.
The caller ignores the return value.

Signed-off-by: Soham Kute <officialsohamkute@gmail.com>
---
 drivers/staging/sm750fb/sm750_accel.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/staging/sm750fb/sm750_accel.c b/drivers/staging/sm750fb/sm750_accel.c
index 1bd0502db039..f2fde011e7ca 100644
--- a/drivers/staging/sm750fb/sm750_accel.c
+++ b/drivers/staging/sm750fb/sm750_accel.c
@@ -152,6 +152,7 @@ int sm750_hw_copyarea(struct lynx_accel *accel,
 		      unsigned int rop2)
 {
 	unsigned int nDirection, de_ctrl;
+	int ret;
 
 	nDirection = LEFT_TO_RIGHT;
 	/* Direction of ROP2 operation: 1 = Left to Right, (-1) = Right to Left */
@@ -261,8 +262,9 @@ int sm750_hw_copyarea(struct lynx_accel *accel,
 		   DE_WINDOW_WIDTH_DST_MASK) |
 		  (sPitch / Bpp & DE_WINDOW_WIDTH_SRC_MASK)); /* dpr3c */
 
-	if (accel->de_wait() != 0)
-		return -1;
+	ret = accel->de_wait();
+	if (ret)
+		return ret;
 
 	write_dpr(accel, DE_SOURCE,
 		  ((sx << DE_SOURCE_X_K1_SHIFT) & DE_SOURCE_X_K1_MASK) |
-- 
2.34.1

[PATCH 4/6] staging: sm750fb: sm750_hw_imageblit: propagate de_wait() error

[Soham Kute]

Propagate the error from accel->de_wait() instead of returning -1.
The caller ignores the return value.

Signed-off-by: Soham Kute <officialsohamkute@gmail.com>
---
 drivers/staging/sm750fb/sm750_accel.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/staging/sm750fb/sm750_accel.c b/drivers/staging/sm750fb/sm750_accel.c
index f2fde011e7ca..7d11810864ae 100644
--- a/drivers/staging/sm750fb/sm750_accel.c
+++ b/drivers/staging/sm750fb/sm750_accel.c
@@ -325,15 +325,16 @@ int sm750_hw_imageblit(struct lynx_accel *accel, const char *pSrcbuf,
 	unsigned int ulBytesRemain;
 	unsigned int de_ctrl = 0;
 	unsigned char ajRemain[4];
-	int i, j;
+	int i, j, ret;
 
 	startBit &= 7; /* Just make sure the start bit is within legal range */
 	ulBytesPerScan = (width + startBit + 7) / 8;
 	ul4BytesPerScan = ulBytesPerScan & ~3;
 	ulBytesRemain = ulBytesPerScan & 3;
 
-	if (accel->de_wait() != 0)
-		return -1;
+	ret = accel->de_wait();
+	if (ret)
+		return ret;
 
 	/*
 	 * 2D Source Base.
-- 
2.34.1

[PATCH 5/6] staging: sm750fb: sw_i2c_write_byte: return -EIO on failure

[Soham Kute]

Return -EIO instead of -1 when the I2C byte write fails.
The caller ignores the return value.

Signed-off-by: Soham Kute <officialsohamkute@gmail.com>
---
 drivers/staging/sm750fb/ddk750_swi2c.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/staging/sm750fb/ddk750_swi2c.c b/drivers/staging/sm750fb/ddk750_swi2c.c
index 0ef8d4ff2ef9..c73943341f66 100644
--- a/drivers/staging/sm750fb/ddk750_swi2c.c
+++ b/drivers/staging/sm750fb/ddk750_swi2c.c
@@ -239,7 +239,7 @@ static void sw_i2c_stop(void)
  *
  *  Return Value:
  *       0   - Success
- *      -1   - Fail to write byte
+ *      -EIO - Fail to write byte
  */
 static long sw_i2c_write_byte(unsigned char data)
 {
@@ -294,7 +294,7 @@ static long sw_i2c_write_byte(unsigned char data)
 	if (i < 0xff)
 		return 0;
 	else
-		return -1;
+		return -EIO;
 }
 
 /*
-- 
2.34.1

[PATCH 6/6] staging: sm750fb: sm750_sw_i2c_init: return -EINVAL for invalid GPIO

[Soham Kute]

Return -EINVAL instead of -1 when the GPIO pin number is out of
range. The caller ignores the return value.

Signed-off-by: Soham Kute <officialsohamkute@gmail.com>
---
 drivers/staging/sm750fb/ddk750_swi2c.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/staging/sm750fb/ddk750_swi2c.c b/drivers/staging/sm750fb/ddk750_swi2c.c
index c73943341f66..46599be8d6b9 100644
--- a/drivers/staging/sm750fb/ddk750_swi2c.c
+++ b/drivers/staging/sm750fb/ddk750_swi2c.c
@@ -344,7 +344,7 @@ static unsigned char sw_i2c_read_byte(unsigned char ack)
  *      data_gpio     - The GPIO pin to be used as i2c SDA
  *
  * Return Value:
- *      -1   - Fail to initialize the i2c
+ *      -EINVAL - Fail to initialize the i2c
  *       0   - Success
  */
 static long sm750le_i2c_init(unsigned char clk_gpio, unsigned char data_gpio)
@@ -382,7 +382,7 @@ static long sm750le_i2c_init(unsigned char clk_gpio, unsigned char data_gpio)
  *      data_gpio     - The GPIO pin to be used as i2c SDA
  *
  * Return Value:
- *      -1   - Fail to initialize the i2c
+ *      -EINVAL - Fail to initialize the i2c
  *       0   - Success
  */
 long sm750_sw_i2c_init(unsigned char clk_gpio, unsigned char data_gpio)
@@ -394,7 +394,7 @@ long sm750_sw_i2c_init(unsigned char clk_gpio, unsigned char data_gpio)
 	 * range is only from [0..63]
 	 */
 	if ((clk_gpio > 31) || (data_gpio > 31))
-		return -1;
+		return -EINVAL;
 
 	if (sm750_get_chip_type() == SM750LE)
 		return sm750le_i2c_init(clk_gpio, data_gpio);
-- 
2.34.1

Re: [PATCH 6/6] staging: sm750fb: sm750_sw_i2c_init: return -EINVAL for invalid GPIO

[Dan Carpenter]

On Wed, Mar 04, 2026 at 11:05:29PM +0530, Soham Kute wrote:
> Return -EINVAL instead of -1 when the GPIO pin number is out of
> range. The caller ignores the return value.
> 
> Signed-off-by: Soham Kute <officialsohamkute@gmail.com>
> ---
>  drivers/staging/sm750fb/ddk750_swi2c.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/staging/sm750fb/ddk750_swi2c.c b/drivers/staging/sm750fb/ddk750_swi2c.c
> index c73943341f66..46599be8d6b9 100644
> --- a/drivers/staging/sm750fb/ddk750_swi2c.c
> +++ b/drivers/staging/sm750fb/ddk750_swi2c.c
> @@ -344,7 +344,7 @@ static unsigned char sw_i2c_read_byte(unsigned char ack)
>   *      data_gpio     - The GPIO pin to be used as i2c SDA
>   *
>   * Return Value:
> - *      -1   - Fail to initialize the i2c
> + *      -EINVAL - Fail to initialize the i2c
>   *       0   - Success
>   */
>  static long sm750le_i2c_init(unsigned char clk_gpio, unsigned char data_gpio)

This part needs to be done in the patch that changes
sw_i2c_read_byte().

regards,
dan carpenter

> @@ -382,7 +382,7 @@ static long sm750le_i2c_init(unsigned char clk_gpio, unsigned char data_gpio)
>   *      data_gpio     - The GPIO pin to be used as i2c SDA
>   *
>   * Return Value:
> - *      -1   - Fail to initialize the i2c
> + *      -EINVAL - Fail to initialize the i2c
>   *       0   - Success
>   */
>  long sm750_sw_i2c_init(unsigned char clk_gpio, unsigned char data_gpio)
> @@ -394,7 +394,7 @@ long sm750_sw_i2c_init(unsigned char clk_gpio, unsigned char data_gpio)
>  	 * range is only from [0..63]
>  	 */
>  	if ((clk_gpio > 31) || (data_gpio > 31))
> -		return -1;
> +		return -EINVAL;
>  
>  	if (sm750_get_chip_type() == SM750LE)
>  		return sm750le_i2c_init(clk_gpio, data_gpio);
> -- 
> 2.34.1
> 

Re: [PATCH 1/6] staging: sm750fb: hw_sm750le_de_wait: return -ETIMEDOUT on timeout

[Dan Carpenter]

On Wed, Mar 04, 2026 at 11:05:24PM +0530, Soham Kute wrote:
> Return -ETIMEDOUT instead of -1 when the DE engine poll loop
> times out. The callers check for non-zero return value and
> propagate the error code back to their callers.
> 

They don't propagate the error back.  The callers do:

drivers/staging/sm750fb/sm750_accel.c
    87  int sm750_hw_fillrect(struct lynx_accel *accel,
    88                        u32 base, u32 pitch, u32 Bpp,
    89                        u32 x, u32 y, u32 width, u32 height,
    90                        u32 color, u32 rop)
    91  {
    92          u32 de_ctrl;
    93  
    94          if (accel->de_wait() != 0) {
    95                  /*
    96                   * int time wait and always busy,seems hardware
    97                   * got something error
    98                   */
    99                  pr_debug("De engine always busy\n");
   100                  return -1;
   101          }

They return -1.  Propagating the errors means:

	ret = accel->de_wait();
	if (ret)
		return ret;

Also this is a v3 patch, it needs v3 in the subject and a little
description of what changed.

https://staticthinking.wordpress.com/2022/07/27/how-to-send-a-v2-patch/

regards,
dan carpenter