[PATCH] spi: stm32: fix NULL check on pointer-to-pointer variable

[PATCH] spi: stm32: fix NULL check on pointer-to-pointer variable

[Antonio Quartulli]

In stm32_spi_prepare_rx_dma_mdma_chaining() both rx_dma_desc
and rx_mdma_desc are passed as pointer-to-pointer arguments.

The goal is to pass back to the caller the value returned
by dmaengine_prep_slave_sg(), when it is not NULL.

However, the NULL check on the result is erroneously
performed without dereferencing the pointer.

Add the proper dereference operator to both checks.

Fixes: d17dd2f1d8a1 ("spi: stm32: use STM32 DMA with STM32 MDMA to enhance DDR use")
Addresses-Coverity-ID: 1644715 ("Null pointer dereferences (REVERSE_INULL)")
Signed-off-by: Antonio Quartulli <antonio@mandelbit.com>
---
 drivers/spi/spi-stm32.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/spi/spi-stm32.c b/drivers/spi/spi-stm32.c
index 3d20f09f1ae7..e9fa17e52fb0 100644
--- a/drivers/spi/spi-stm32.c
+++ b/drivers/spi/spi-stm32.c
@@ -1529,7 +1529,7 @@ static int stm32_spi_prepare_rx_dma_mdma_chaining(struct stm32_spi *spi,
 					       DMA_PREP_INTERRUPT);
 	sg_free_table(&dma_sgt);
 
-	if (!rx_dma_desc)
+	if (!*rx_dma_desc)
 		return -EINVAL;
 
 	/* Prepare MDMA slave_sg transfer MEM_TO_MEM (SRAM>DDR) */
@@ -1563,8 +1563,8 @@ static int stm32_spi_prepare_rx_dma_mdma_chaining(struct stm32_spi *spi,
 						DMA_PREP_INTERRUPT);
 	sg_free_table(&mdma_sgt);
 
-	if (!rx_mdma_desc) {
-		rx_dma_desc = NULL;
+	if (!*rx_mdma_desc) {
+		*rx_dma_desc = NULL;
 		return -EINVAL;
 	}
 
-- 
2.49.0

Re: [PATCH] spi: stm32: fix NULL check on pointer-to-pointer variable

[Clement LE GOFFIC]

Hi Antonio,

On 6/28/25 02:02, Antonio Quartulli wrote:
> In stm32_spi_prepare_rx_dma_mdma_chaining() both rx_dma_desc
> and rx_mdma_desc are passed as pointer-to-pointer arguments.
> 
> The goal is to pass back to the caller the value returned
> by dmaengine_prep_slave_sg(), when it is not NULL.
> 
> However, the NULL check on the result is erroneously
> performed without dereferencing the pointer.
> 
> Add the proper dereference operator to both checks.
> 
> Fixes: d17dd2f1d8a1 ("spi: stm32: use STM32 DMA with STM32 MDMA to enhance DDR use")
> Addresses-Coverity-ID: 1644715 ("Null pointer dereferences (REVERSE_INULL)")
> Signed-off-by: Antonio Quartulli <antonio@mandelbit.com>
> ---
>   drivers/spi/spi-stm32.c | 6 +++---
>   1 file changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/spi/spi-stm32.c b/drivers/spi/spi-stm32.c
> index 3d20f09f1ae7..e9fa17e52fb0 100644
> --- a/drivers/spi/spi-stm32.c
> +++ b/drivers/spi/spi-stm32.c
> @@ -1529,7 +1529,7 @@ static int stm32_spi_prepare_rx_dma_mdma_chaining(struct stm32_spi *spi,
>   					       DMA_PREP_INTERRUPT);
>   	sg_free_table(&dma_sgt);
>   
> -	if (!rx_dma_desc)
> +	if (!*rx_dma_desc)
>   		return -EINVAL;
>   
>   	/* Prepare MDMA slave_sg transfer MEM_TO_MEM (SRAM>DDR) */
> @@ -1563,8 +1563,8 @@ static int stm32_spi_prepare_rx_dma_mdma_chaining(struct stm32_spi *spi,
>   						DMA_PREP_INTERRUPT);
>   	sg_free_table(&mdma_sgt);
>   
> -	if (!rx_mdma_desc) {
> -		rx_dma_desc = NULL;
> +	if (!*rx_mdma_desc) {
> +		*rx_dma_desc = NULL;
>   		return -EINVAL;
>   	}
>   

Good catch for both pointers !

For readability, I would suggest to define two dma_async_tx_descriptor 
ptr at the beginning of the function such as :
	struct dma_async_tx_descriptor *_mdma_desc = *rx_mdma_desc;
	struct dma_async_tx_descriptor *_dma_desc = *rx_dma_desc;

And then use them all along the function even in the assignation.

Best regards,
Clément

Re: [PATCH] spi: stm32: fix NULL check on pointer-to-pointer variable

[Antonio Quartulli]

Hi Clement,

On 30/06/2025 09:34, Clement LE GOFFIC wrote:
> Hi Antonio,
> 
> On 6/28/25 02:02, Antonio Quartulli wrote:
>> In stm32_spi_prepare_rx_dma_mdma_chaining() both rx_dma_desc
>> and rx_mdma_desc are passed as pointer-to-pointer arguments.
>>
>> The goal is to pass back to the caller the value returned
>> by dmaengine_prep_slave_sg(), when it is not NULL.
>>
>> However, the NULL check on the result is erroneously
>> performed without dereferencing the pointer.
>>
>> Add the proper dereference operator to both checks.
>>
>> Fixes: d17dd2f1d8a1 ("spi: stm32: use STM32 DMA with STM32 MDMA to 
>> enhance DDR use")
>> Addresses-Coverity-ID: 1644715 ("Null pointer dereferences 
>> (REVERSE_INULL)")
>> Signed-off-by: Antonio Quartulli <antonio@mandelbit.com>
>> ---
>>   drivers/spi/spi-stm32.c | 6 +++---
>>   1 file changed, 3 insertions(+), 3 deletions(-)
>>
>> diff --git a/drivers/spi/spi-stm32.c b/drivers/spi/spi-stm32.c
>> index 3d20f09f1ae7..e9fa17e52fb0 100644
>> --- a/drivers/spi/spi-stm32.c
>> +++ b/drivers/spi/spi-stm32.c
>> @@ -1529,7 +1529,7 @@ static int 
>> stm32_spi_prepare_rx_dma_mdma_chaining(struct stm32_spi *spi,
>>                              DMA_PREP_INTERRUPT);
>>       sg_free_table(&dma_sgt);
>> -    if (!rx_dma_desc)
>> +    if (!*rx_dma_desc)
>>           return -EINVAL;
>>       /* Prepare MDMA slave_sg transfer MEM_TO_MEM (SRAM>DDR) */
>> @@ -1563,8 +1563,8 @@ static int 
>> stm32_spi_prepare_rx_dma_mdma_chaining(struct stm32_spi *spi,
>>                           DMA_PREP_INTERRUPT);
>>       sg_free_table(&mdma_sgt);
>> -    if (!rx_mdma_desc) {
>> -        rx_dma_desc = NULL;
>> +    if (!*rx_mdma_desc) {
>> +        *rx_dma_desc = NULL;
>>           return -EINVAL;
>>       }
> 
> Good catch for both pointers !
> 
> For readability, I would suggest to define two dma_async_tx_descriptor 
> ptr at the beginning of the function such as :
>      struct dma_async_tx_descriptor *_mdma_desc = *rx_mdma_desc;
>      struct dma_async_tx_descriptor *_dma_desc = *rx_dma_desc;
> 
> And then use them all along the function even in the assignation.
> 

Thanks for the comment.
Will send v2!

Regards,


-- 
Antonio Quartulli

CEO and Co-Founder
Mandelbit Srl
https://www.mandelbit.com

[PATCH v2] spi: stm32: fix pointer-to-pointer variables usage

[Antonio Quartulli]

In stm32_spi_prepare_rx_dma_mdma_chaining() both rx_dma_desc
and rx_mdma_desc are passed as pointer-to-pointer arguments.

The goal is to pass back to the caller the value returned
by dmaengine_prep_slave_sg(), when it is not NULL.

However, these variables are wrongly handled as simple pointers
during later assignments and checks.

Fix this behaviour by introducing two pointer variables
which can then be treated accordingly.

Fixes: d17dd2f1d8a1 ("spi: stm32: use STM32 DMA with STM32 MDMA to enhance DDR use")
Addresses-Coverity-ID: 1644715 ("Null pointer dereferences (REVERSE_INULL)")
Signed-off-by: Antonio Quartulli <antonio@mandelbit.com>

---
Changes from v1:
* introduce *_mdma_desc and *_dma_desc for better readability
* fix another instance of rx_dma_desc bogus assignment in case of
  failure of sg_alloc_table()
* commit title/message reworded accordingly to the previous point
---
 drivers/spi/spi-stm32.c | 22 ++++++++++++----------
 1 file changed, 12 insertions(+), 10 deletions(-)

diff --git a/drivers/spi/spi-stm32.c b/drivers/spi/spi-stm32.c
index 3d20f09f1ae7..4b7f074fdba9 100644
--- a/drivers/spi/spi-stm32.c
+++ b/drivers/spi/spi-stm32.c
@@ -1474,6 +1474,8 @@ static int stm32_spi_prepare_rx_dma_mdma_chaining(struct stm32_spi *spi,
 						  struct dma_async_tx_descriptor **rx_dma_desc,
 						  struct dma_async_tx_descriptor **rx_mdma_desc)
 {
+	struct dma_async_tx_descriptor *_mdma_desc = *rx_mdma_desc;
+	struct dma_async_tx_descriptor *_dma_desc = *rx_dma_desc;
 	struct dma_slave_config rx_mdma_conf = {0};
 	u32 sram_period, nents = 0, spi_s_len;
 	struct sg_table dma_sgt, mdma_sgt;
@@ -1524,18 +1526,18 @@ static int stm32_spi_prepare_rx_dma_mdma_chaining(struct stm32_spi *spi,
 		}
 	}
 
-	*rx_dma_desc = dmaengine_prep_slave_sg(spi->dma_rx, dma_sgt.sgl,
-					       dma_sgt.nents, rx_dma_conf->direction,
-					       DMA_PREP_INTERRUPT);
+	_dma_desc = dmaengine_prep_slave_sg(spi->dma_rx, dma_sgt.sgl,
+					    dma_sgt.nents, rx_dma_conf->direction,
+					    DMA_PREP_INTERRUPT);
 	sg_free_table(&dma_sgt);
 
-	if (!rx_dma_desc)
+	if (!_dma_desc)
 		return -EINVAL;
 
 	/* Prepare MDMA slave_sg transfer MEM_TO_MEM (SRAM>DDR) */
 	ret = sg_alloc_table(&mdma_sgt, nents, GFP_ATOMIC);
 	if (ret) {
-		rx_dma_desc = NULL;
+		_dma_desc = NULL;
 		return ret;
 	}
 
@@ -1558,13 +1560,13 @@ static int stm32_spi_prepare_rx_dma_mdma_chaining(struct stm32_spi *spi,
 		}
 	}
 
-	*rx_mdma_desc = dmaengine_prep_slave_sg(spi->mdma_rx, mdma_sgt.sgl,
-						mdma_sgt.nents, rx_mdma_conf.direction,
-						DMA_PREP_INTERRUPT);
+	_mdma_desc = dmaengine_prep_slave_sg(spi->mdma_rx, mdma_sgt.sgl,
+					     mdma_sgt.nents, rx_mdma_conf.direction,
+					     DMA_PREP_INTERRUPT);
 	sg_free_table(&mdma_sgt);
 
-	if (!rx_mdma_desc) {
-		rx_dma_desc = NULL;
+	if (!_mdma_desc) {
+		_dma_desc = NULL;
 		return -EINVAL;
 	}
 
-- 
2.49.0

Re: [PATCH v2] spi: stm32: fix pointer-to-pointer variables usage

[Clement LE GOFFIC]

On 6/30/25 10:12, Antonio Quartulli wrote:
> In stm32_spi_prepare_rx_dma_mdma_chaining() both rx_dma_desc
> and rx_mdma_desc are passed as pointer-to-pointer arguments.
> 
> The goal is to pass back to the caller the value returned
> by dmaengine_prep_slave_sg(), when it is not NULL.
> 
> However, these variables are wrongly handled as simple pointers
> during later assignments and checks.
> 
> Fix this behaviour by introducing two pointer variables
> which can then be treated accordingly.
> 
> Fixes: d17dd2f1d8a1 ("spi: stm32: use STM32 DMA with STM32 MDMA to enhance DDR use")
> Addresses-Coverity-ID: 1644715 ("Null pointer dereferences (REVERSE_INULL)")
> Signed-off-by: Antonio Quartulli <antonio@mandelbit.com>
> 
> ---
> Changes from v1:
> * introduce *_mdma_desc and *_dma_desc for better readability
> * fix another instance of rx_dma_desc bogus assignment in case of
>    failure of sg_alloc_table()
> * commit title/message reworded accordingly to the previous point
> ---
>   drivers/spi/spi-stm32.c | 22 ++++++++++++----------
>   1 file changed, 12 insertions(+), 10 deletions(-)
> 
> diff --git a/drivers/spi/spi-stm32.c b/drivers/spi/spi-stm32.c
> index 3d20f09f1ae7..4b7f074fdba9 100644
> --- a/drivers/spi/spi-stm32.c
> +++ b/drivers/spi/spi-stm32.c
> @@ -1474,6 +1474,8 @@ static int stm32_spi_prepare_rx_dma_mdma_chaining(struct stm32_spi *spi,
>   						  struct dma_async_tx_descriptor **rx_dma_desc,
>   						  struct dma_async_tx_descriptor **rx_mdma_desc)
>   {
> +	struct dma_async_tx_descriptor *_mdma_desc = *rx_mdma_desc;
> +	struct dma_async_tx_descriptor *_dma_desc = *rx_dma_desc;
>   	struct dma_slave_config rx_mdma_conf = {0};
>   	u32 sram_period, nents = 0, spi_s_len;
>   	struct sg_table dma_sgt, mdma_sgt;
> @@ -1524,18 +1526,18 @@ static int stm32_spi_prepare_rx_dma_mdma_chaining(struct stm32_spi *spi,
>   		}
>   	}
>   
> -	*rx_dma_desc = dmaengine_prep_slave_sg(spi->dma_rx, dma_sgt.sgl,
> -					       dma_sgt.nents, rx_dma_conf->direction,
> -					       DMA_PREP_INTERRUPT);
> +	_dma_desc = dmaengine_prep_slave_sg(spi->dma_rx, dma_sgt.sgl,
> +					    dma_sgt.nents, rx_dma_conf->direction,
> +					    DMA_PREP_INTERRUPT);
>   	sg_free_table(&dma_sgt);
>   
> -	if (!rx_dma_desc)
> +	if (!_dma_desc)
>   		return -EINVAL;
>   
>   	/* Prepare MDMA slave_sg transfer MEM_TO_MEM (SRAM>DDR) */
>   	ret = sg_alloc_table(&mdma_sgt, nents, GFP_ATOMIC);
>   	if (ret) {
> -		rx_dma_desc = NULL;
> +		_dma_desc = NULL;
>   		return ret;
>   	}
>   
> @@ -1558,13 +1560,13 @@ static int stm32_spi_prepare_rx_dma_mdma_chaining(struct stm32_spi *spi,
>   		}
>   	}
>   
> -	*rx_mdma_desc = dmaengine_prep_slave_sg(spi->mdma_rx, mdma_sgt.sgl,
> -						mdma_sgt.nents, rx_mdma_conf.direction,
> -						DMA_PREP_INTERRUPT);
> +	_mdma_desc = dmaengine_prep_slave_sg(spi->mdma_rx, mdma_sgt.sgl,
> +					     mdma_sgt.nents, rx_mdma_conf.direction,
> +					     DMA_PREP_INTERRUPT);
>   	sg_free_table(&mdma_sgt);
>   
> -	if (!rx_mdma_desc) {
> -		rx_dma_desc = NULL;
> +	if (!_mdma_desc) {
> +		_dma_desc = NULL;
>   		return -EINVAL;
>   	}
>   

Thank you, LGTM
You can add my Reviewed-by

Best regards,
Clément

Re: [PATCH v2] spi: stm32: fix pointer-to-pointer variables usage

[Mark Brown]

[-- Attachment #1: Type: text/plain, Size: 243 bytes --]

On Mon, Jun 30, 2025 at 10:28:50AM +0200, Clement LE GOFFIC wrote:

> Thank you, LGTM
> You can add my Reviewed-by

If you want to add a Reviewed-by you should actually write it out in the
mail, people rely on tooling like b4 to pick them up.

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 488 bytes --]

Re: [PATCH v2] spi: stm32: fix pointer-to-pointer variables usage

[Clement LE GOFFIC]

On 6/30/25 13:20, Mark Brown wrote:
> On Mon, Jun 30, 2025 at 10:28:50AM +0200, Clement LE GOFFIC wrote:
> 
>> Thank you, LGTM
>> You can add my Reviewed-by
> 
> If you want to add a Reviewed-by you should actually write it out in the
> mail, people rely on tooling like b4 to pick them up.

Yes, sorry.
Fixed it.

Best regards,
Clément

Re: [PATCH v2] spi: stm32: fix pointer-to-pointer variables usage

[Alain Volmat]

Hi Antonio,

Thank you for the patch.

On Mon, Jun 30, 2025 at 10:12:53AM +0200, Antonio Quartulli wrote:
> In stm32_spi_prepare_rx_dma_mdma_chaining() both rx_dma_desc
> and rx_mdma_desc are passed as pointer-to-pointer arguments.
> 
> The goal is to pass back to the caller the value returned
> by dmaengine_prep_slave_sg(), when it is not NULL.
> 
> However, these variables are wrongly handled as simple pointers
> during later assignments and checks.
> 
> Fix this behaviour by introducing two pointer variables
> which can then be treated accordingly.
> 
> Fixes: d17dd2f1d8a1 ("spi: stm32: use STM32 DMA with STM32 MDMA to enhance DDR use")
> Addresses-Coverity-ID: 1644715 ("Null pointer dereferences (REVERSE_INULL)")
> Signed-off-by: Antonio Quartulli <antonio@mandelbit.com>
> 
> ---
> Changes from v1:
> * introduce *_mdma_desc and *_dma_desc for better readability
> * fix another instance of rx_dma_desc bogus assignment in case of
>   failure of sg_alloc_table()
> * commit title/message reworded accordingly to the previous point
> ---
>  drivers/spi/spi-stm32.c | 22 ++++++++++++----------
>  1 file changed, 12 insertions(+), 10 deletions(-)
> 
> diff --git a/drivers/spi/spi-stm32.c b/drivers/spi/spi-stm32.c
> index 3d20f09f1ae7..4b7f074fdba9 100644
> --- a/drivers/spi/spi-stm32.c
> +++ b/drivers/spi/spi-stm32.c
> @@ -1474,6 +1474,8 @@ static int stm32_spi_prepare_rx_dma_mdma_chaining(struct stm32_spi *spi,
>  						  struct dma_async_tx_descriptor **rx_dma_desc,
>  						  struct dma_async_tx_descriptor **rx_mdma_desc)
>  {
> +	struct dma_async_tx_descriptor *_mdma_desc = *rx_mdma_desc;
> +	struct dma_async_tx_descriptor *_dma_desc = *rx_dma_desc;
>  	struct dma_slave_config rx_mdma_conf = {0};
>  	u32 sram_period, nents = 0, spi_s_len;
>  	struct sg_table dma_sgt, mdma_sgt;
> @@ -1524,18 +1526,18 @@ static int stm32_spi_prepare_rx_dma_mdma_chaining(struct stm32_spi *spi,
>  		}
>  	}
>  
> -	*rx_dma_desc = dmaengine_prep_slave_sg(spi->dma_rx, dma_sgt.sgl,
> -					       dma_sgt.nents, rx_dma_conf->direction,
> -					       DMA_PREP_INTERRUPT);
> +	_dma_desc = dmaengine_prep_slave_sg(spi->dma_rx, dma_sgt.sgl,
> +					    dma_sgt.nents, rx_dma_conf->direction,
> +					    DMA_PREP_INTERRUPT);
>  	sg_free_table(&dma_sgt);
>  
> -	if (!rx_dma_desc)
> +	if (!_dma_desc)
>  		return -EINVAL;
>  
>  	/* Prepare MDMA slave_sg transfer MEM_TO_MEM (SRAM>DDR) */
>  	ret = sg_alloc_table(&mdma_sgt, nents, GFP_ATOMIC);
>  	if (ret) {
> -		rx_dma_desc = NULL;
> +		_dma_desc = NULL;
>  		return ret;
>  	}
>  
> @@ -1558,13 +1560,13 @@ static int stm32_spi_prepare_rx_dma_mdma_chaining(struct stm32_spi *spi,
>  		}
>  	}
>  
> -	*rx_mdma_desc = dmaengine_prep_slave_sg(spi->mdma_rx, mdma_sgt.sgl,
> -						mdma_sgt.nents, rx_mdma_conf.direction,
> -						DMA_PREP_INTERRUPT);
> +	_mdma_desc = dmaengine_prep_slave_sg(spi->mdma_rx, mdma_sgt.sgl,
> +					     mdma_sgt.nents, rx_mdma_conf.direction,
> +					     DMA_PREP_INTERRUPT);
>  	sg_free_table(&mdma_sgt);
>  
> -	if (!rx_mdma_desc) {
> -		rx_dma_desc = NULL;
> +	if (!_mdma_desc) {
> +		_dma_desc = NULL;
>  		return -EINVAL;
>  	}
>  

Acked-by: Alain Volmat <alain.volmat@foss.st.com>

Regards,
Alain
> -- 
> 2.49.0
> 

Re: [PATCH v2] spi: stm32: fix pointer-to-pointer variables usage

[Clement LE GOFFIC]

On 6/30/25 10:12, Antonio Quartulli wrote:
> In stm32_spi_prepare_rx_dma_mdma_chaining() both rx_dma_desc
> and rx_mdma_desc are passed as pointer-to-pointer arguments.
> 
> The goal is to pass back to the caller the value returned
> by dmaengine_prep_slave_sg(), when it is not NULL.
> 
> However, these variables are wrongly handled as simple pointers
> during later assignments and checks.
> 
> Fix this behaviour by introducing two pointer variables
> which can then be treated accordingly.
> 
> Fixes: d17dd2f1d8a1 ("spi: stm32: use STM32 DMA with STM32 MDMA to enhance DDR use")
> Addresses-Coverity-ID: 1644715 ("Null pointer dereferences (REVERSE_INULL)")
> Signed-off-by: Antonio Quartulli <antonio@mandelbit.com>
> 
> ---
> Changes from v1:
> * introduce *_mdma_desc and *_dma_desc for better readability
> * fix another instance of rx_dma_desc bogus assignment in case of
>    failure of sg_alloc_table()
> * commit title/message reworded accordingly to the previous point
> ---
>   drivers/spi/spi-stm32.c | 22 ++++++++++++----------
>   1 file changed, 12 insertions(+), 10 deletions(-)
> 
> diff --git a/drivers/spi/spi-stm32.c b/drivers/spi/spi-stm32.c
> index 3d20f09f1ae7..4b7f074fdba9 100644
> --- a/drivers/spi/spi-stm32.c
> +++ b/drivers/spi/spi-stm32.c
> @@ -1474,6 +1474,8 @@ static int stm32_spi_prepare_rx_dma_mdma_chaining(struct stm32_spi *spi,
>   						  struct dma_async_tx_descriptor **rx_dma_desc,
>   						  struct dma_async_tx_descriptor **rx_mdma_desc)
>   {
> +	struct dma_async_tx_descriptor *_mdma_desc = *rx_mdma_desc;
> +	struct dma_async_tx_descriptor *_dma_desc = *rx_dma_desc;
>   	struct dma_slave_config rx_mdma_conf = {0};
>   	u32 sram_period, nents = 0, spi_s_len;
>   	struct sg_table dma_sgt, mdma_sgt;
> @@ -1524,18 +1526,18 @@ static int stm32_spi_prepare_rx_dma_mdma_chaining(struct stm32_spi *spi,
>   		}
>   	}
>   
> -	*rx_dma_desc = dmaengine_prep_slave_sg(spi->dma_rx, dma_sgt.sgl,
> -					       dma_sgt.nents, rx_dma_conf->direction,
> -					       DMA_PREP_INTERRUPT);
> +	_dma_desc = dmaengine_prep_slave_sg(spi->dma_rx, dma_sgt.sgl,
> +					    dma_sgt.nents, rx_dma_conf->direction,
> +					    DMA_PREP_INTERRUPT);
>   	sg_free_table(&dma_sgt);
>   
> -	if (!rx_dma_desc)
> +	if (!_dma_desc)
>   		return -EINVAL;
>   
>   	/* Prepare MDMA slave_sg transfer MEM_TO_MEM (SRAM>DDR) */
>   	ret = sg_alloc_table(&mdma_sgt, nents, GFP_ATOMIC);
>   	if (ret) {
> -		rx_dma_desc = NULL;
> +		_dma_desc = NULL;
>   		return ret;
>   	}
>   
> @@ -1558,13 +1560,13 @@ static int stm32_spi_prepare_rx_dma_mdma_chaining(struct stm32_spi *spi,
>   		}
>   	}
>   
> -	*rx_mdma_desc = dmaengine_prep_slave_sg(spi->mdma_rx, mdma_sgt.sgl,
> -						mdma_sgt.nents, rx_mdma_conf.direction,
> -						DMA_PREP_INTERRUPT);
> +	_mdma_desc = dmaengine_prep_slave_sg(spi->mdma_rx, mdma_sgt.sgl,
> +					     mdma_sgt.nents, rx_mdma_conf.direction,
> +					     DMA_PREP_INTERRUPT);
>   	sg_free_table(&mdma_sgt);
>   
> -	if (!rx_mdma_desc) {
> -		rx_dma_desc = NULL;
> +	if (!_mdma_desc) {
> +		_dma_desc = NULL;
>   		return -EINVAL;
>   	}
>   

Reviewed-by: Clément Le Goffic <clement.legoffic@foss.st.com>

Re: [PATCH v2] spi: stm32: fix pointer-to-pointer variables usage

[Mark Brown]

On Mon, 30 Jun 2025 10:12:53 +0200, Antonio Quartulli wrote:
> In stm32_spi_prepare_rx_dma_mdma_chaining() both rx_dma_desc
> and rx_mdma_desc are passed as pointer-to-pointer arguments.
> 
> The goal is to pass back to the caller the value returned
> by dmaengine_prep_slave_sg(), when it is not NULL.
> 
> However, these variables are wrongly handled as simple pointers
> during later assignments and checks.
> 
> [...]

Applied to

   https://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi.git for-next

Thanks!

[1/1] spi: stm32: fix pointer-to-pointer variables usage
      commit: c4f2c05ab02952c9a56067aeb700ded95b183570

All being well this means that it will be integrated into the linux-next
tree (usually sometime in the next 24 hours) and sent to Linus during
the next merge window (or sooner if it is a bug fix), however if
problems are discovered then the patch may be dropped or reverted.

You may get further e-mails resulting from automated or manual testing
and review of the tree, please engage with people reporting problems and
send followup patches addressing any issues that are reported if needed.

If any updates are required or you are submitting further changes they
should be sent as incremental updates against current git, existing
patches will not be replaced.

Please add any relevant lists and maintainers to the CCs when replying
to this mail.

Thanks,
Mark