Re: [PATCH] scsi: hisi_sas: Remove useless DMA-32 fallback configuration

[John Garry]

On 15/01/2022 09:05, Christophe JAILLET wrote:
> As stated in [1], dma_set_mask() with a 64-bit mask never fails if
> dev->dma_mask is non-NULL.
> So, if it fails, the 32 bits case will also fail for the same reason.
>
> Simplify code and remove some dead code accordingly.
>
> [1]: https://lore.kernel.org/linux-kernel/YL3vSPK5DXTNvgdx@xxxxxxxxxxxxx/#t
>
> Signed-off-by: Christophe JAILLET <christophe.jaillet@xxxxxxxxxx>

Great, you got both callsites:

Acked-by: John Garry <john.garry@xxxxxxxxxx>

> ---
>   drivers/scsi/hisi_sas/hisi_sas_main.c  | 3 ---
>   drivers/scsi/hisi_sas/hisi_sas_v3_hw.c | 2 --
>   2 files changed, 5 deletions(-)
>
> diff --git a/drivers/scsi/hisi_sas/hisi_sas_main.c b/drivers/scsi/hisi_sas/hisi_sas_main.c
> index a05ec7aece5a..2f53a2ee024a 100644
> --- a/drivers/scsi/hisi_sas/hisi_sas_main.c
> +++ b/drivers/scsi/hisi_sas/hisi_sas_main.c
> @@ -2666,9 +2666,6 @@ static struct Scsi_Host *hisi_sas_shost_alloc(struct platform_device *pdev,
>   		goto err_out;
>   
>   	error = dma_set_mask_and_coherent(dev, DMA_BIT_MASK(64));
> -	if (error)
> -		error = dma_set_mask_and_coherent(dev, DMA_BIT_MASK(32));
> -
>   	if (error) {
>   		dev_err(dev, "No usable DMA addressing method\n");
>   		goto err_out;
> diff --git a/drivers/scsi/hisi_sas/hisi_sas_v3_hw.c b/drivers/scsi/hisi_sas/hisi_sas_v3_hw.c
> index a45ef9a5e12e..a01a3a7b706b 100644
> --- a/drivers/scsi/hisi_sas/hisi_sas_v3_hw.c
> +++ b/drivers/scsi/hisi_sas/hisi_sas_v3_hw.c
> @@ -4695,8 +4695,6 @@ hisi_sas_v3_probe(struct pci_dev *pdev, const struct pci_device_id *id)
>   		goto err_out;
>   
>   	rc = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(64));
> -	if (rc)
> -		rc = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32));
>   	if (rc) {
>   		dev_err(dev, "No usable DMA addressing method\n");
>   		rc = -ENODEV;