[PATCH] i40e: Remove useless DMA-32 fallback configuration

Christophe JAILLET posted 1 patch 4 years, 5 months ago
drivers/net/ethernet/intel/i40e/i40e_main.c | 9 +++------
1 file changed, 3 insertions(+), 6 deletions(-)
[PATCH] i40e: Remove useless DMA-32 fallback configuration
Posted by Christophe JAILLET 4 years, 5 months ago
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://lkml.org/lkml/2021/6/7/398

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Alexander Lobakin <alexandr.lobakin@intel.com>
---
 drivers/net/ethernet/intel/i40e/i40e_main.c | 9 +++------
 1 file changed, 3 insertions(+), 6 deletions(-)

diff --git a/drivers/net/ethernet/intel/i40e/i40e_main.c b/drivers/net/ethernet/intel/i40e/i40e_main.c
index 2a3d8aef7f4e..0f11d3f5c98a 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_main.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_main.c
@@ -15324,12 +15324,9 @@ static int i40e_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 	/* set up for high or low dma */
 	err = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(64));
 	if (err) {
-		err = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32));
-		if (err) {
-			dev_err(&pdev->dev,
-				"DMA configuration failed: 0x%x\n", err);
-			goto err_dma;
-		}
+		dev_err(&pdev->dev,
+			"DMA configuration failed: 0x%x\n", err);
+		goto err_dma;
 	}
 
 	/* set up pci connections */
-- 
2.32.0

RE: [PATCH] i40e: Remove useless DMA-32 fallback configuration
Posted by G, GurucharanX 4 years, 5 months ago

> -----Original Message-----
> From: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
> Sent: Sunday, January 9, 2022 11:00 PM
> To: Brandeburg, Jesse <jesse.brandeburg@intel.com>; Nguyen, Anthony L
> <anthony.l.nguyen@intel.com>; David S. Miller <davem@davemloft.net>;
> Jakub Kicinski <kuba@kernel.org>
> Cc: linux-kernel@vger.kernel.org; kernel-janitors@vger.kernel.org;
> Christophe JAILLET <christophe.jaillet@wanadoo.fr>; Christoph Hellwig
> <hch@lst.de>; Lobakin, Alexandr <alexandr.lobakin@intel.com>; intel-wired-
> lan@lists.osuosl.org; netdev@vger.kernel.org
> Subject: [PATCH] i40e: Remove useless DMA-32 fallback configuration
> 
> 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://lkml.org/lkml/2021/6/7/398
> 
> Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
> Reviewed-by: Christoph Hellwig <hch@lst.de>
> Reviewed-by: Alexander Lobakin <alexandr.lobakin@intel.com>
> ---
>  drivers/net/ethernet/intel/i40e/i40e_main.c | 9 +++------
>  1 file changed, 3 insertions(+), 6 deletions(-)
> 

Tested-by: Gurucharan G <gurucharanx.g@intel.com> (A Contingent worker at Intel)