Re: [PATCH v2] atm: idt77252: Add missing `dma_map_error()`

[Thomas Fourier <fourier.thomas@gmail.com>]

On 24/06/2025 18:51, Simon Horman wrote:
> On Tue, Jun 24, 2025 at 08:41:47AM +0200, Thomas Fourier wrote:
>> The DMA map functions can fail and should be tested for errors.
>>
>> Signed-off-by: Thomas Fourier <fourier.thomas@gmail.com>
>> ---
>>   drivers/atm/idt77252.c | 5 +++++
>>   1 file changed, 5 insertions(+)
>>
>> diff --git a/drivers/atm/idt77252.c b/drivers/atm/idt77252.c
>> index 1206ab764ba9..f2e91b7d79f0 100644
>> --- a/drivers/atm/idt77252.c
>> +++ b/drivers/atm/idt77252.c
>> @@ -852,6 +852,8 @@ queue_skb(struct idt77252_dev *card, struct vc_map *vc,
>>   
>>   	IDT77252_PRV_PADDR(skb) = dma_map_single(&card->pcidev->dev, skb->data,
>>   						 skb->len, DMA_TO_DEVICE);
>> +	if (dma_mapping_error(&card->pcidev->dev, IDT77252_PRV_PADDR(skb)))
>> +		return -ENOMEM;
>>   
>>   	error = -EINVAL;
>>   
>> @@ -1857,6 +1859,8 @@ add_rx_skb(struct idt77252_dev *card, int queue,
>>   		paddr = dma_map_single(&card->pcidev->dev, skb->data,
>>   				       skb_end_pointer(skb) - skb->data,
>>   				       DMA_FROM_DEVICE);
>> +		if (dma_mapping_error(&card->pcidev->dev, paddr))
>> +			goto outpoolrm;
>>   		IDT77252_PRV_PADDR(skb) = paddr;
>>   
>>   		if (push_rx_skb(card, skb, queue)) {
>> @@ -1871,6 +1875,7 @@ add_rx_skb(struct idt77252_dev *card, int queue,
>>   	dma_unmap_single(&card->pcidev->dev, IDT77252_PRV_PADDR(skb),
>>   			 skb_end_pointer(skb) - skb->data, DMA_FROM_DEVICE);
>>   
>> +outpoolrm:
>>   	handle = IDT77252_PRV_POOL(skb);
>>   	card->sbpool[POOL_QUEUE(handle)].skb[POOL_INDEX(handle)] = NULL;
> Hi Thomas,
>
> Can sb_pool_remove() be used here?
> It seems to be the converse of sb_pool_add().
> And safer than the code above.
> But perhaps I'm missing something.


Hi Simon,

I don't see any reason why this would be a problem,

though, I don't think it is related and the change should be in the same 
patch.

Should I create another patch for that?