[PATCH] scsi: 3w-sas: Remove useless DMA-32 fallback configuration

[PATCH] scsi: 3w-sas: Remove useless DMA-32 fallback configuration

[Christophe JAILLET]

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@infradead.org/#t

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
---
 drivers/scsi/3w-sas.c | 4 ----
 1 file changed, 4 deletions(-)

diff --git a/drivers/scsi/3w-sas.c b/drivers/scsi/3w-sas.c
index b9482da79512..3ebe66151dcb 100644
--- a/drivers/scsi/3w-sas.c
+++ b/drivers/scsi/3w-sas.c
@@ -1567,8 +1567,6 @@ static int twl_probe(struct pci_dev *pdev, const struct pci_device_id *dev_id)
 	pci_try_set_mwi(pdev);
 
 	retval = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(64));
-	if (retval)
-		retval = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32));
 	if (retval) {
 		TW_PRINTK(host, TW_DRIVER, 0x18, "Failed to set dma mask");
 		retval = -ENODEV;
@@ -1786,8 +1784,6 @@ static int __maybe_unused twl_resume(struct device *dev)
 	pci_try_set_mwi(pdev);
 
 	retval = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(64));
-	if (retval)
-		retval = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32));
 	if (retval) {
 		TW_PRINTK(host, TW_DRIVER, 0x25, "Failed to set dma mask during resume");
 		retval = -ENODEV;
-- 
2.32.0

Re: [PATCH] scsi: 3w-sas: Remove useless DMA-32 fallback configuration

[Martin K. Petersen]

Christophe,

> 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.

Applied to 5.17/scsi-staging, thanks!

-- 
Martin K. Petersen	Oracle Linux Engineering

Re: [PATCH] scsi: 3w-sas: Remove useless DMA-32 fallback configuration

[Martin K. Petersen]

On Sat, 15 Jan 2022 09:53:03 +0100, 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@infradead.org/#t
> 
> [...]

Applied to 5.17/scsi-fixes, thanks!

[1/1] scsi: 3w-sas: Remove useless DMA-32 fallback configuration
      https://git.kernel.org/mkp/scsi/c/fb8d5ea8fd90

-- 
Martin K. Petersen	Oracle Linux Engineering