diff mbox series

ixgbe: Remove useless DMA-32 fallback configuration

Message ID aafc0597758dd8ba58c15e4bf2e669872246c839.1641748850.git.christophe.jaillet@wanadoo.fr (mailing list archive)
State Awaiting Upstream
Delegated to: Netdev Maintainers
Headers show
Series ixgbe: Remove useless DMA-32 fallback configuration | expand

Checks

Context Check Description
netdev/fixes_present success Fixes tag not required for -next series
netdev/subject_prefix warning Target tree name not specified in the subject
netdev/cover_letter success Single patches do not need cover letters
netdev/patch_count success Link
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 1 this patch: 1
netdev/cc_maintainers success CCed 6 of 6 maintainers
netdev/build_clang success Errors and warnings before: 0 this patch: 0
netdev/module_param success Was 0 now: 0
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 1 this patch: 1
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 40 lines checked
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0
netdev/tree_selection success Guessing tree name failed - patch did not apply

Commit Message

Christophe JAILLET Jan. 9, 2022, 5:20 p.m. UTC 
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.

So, if dma_set_mask_and_coherent() succeeds, 'pci_using_dac' is known to be
1.

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/ixgbe/ixgbe_main.c | 20 +++++++------------
 1 file changed, 7 insertions(+), 13 deletions(-)

Comments

Christoph Hellwig Jan. 10, 2022, 7:11 a.m. UTC | #1 
Looks good,

Reviewed-by: Christoph Hellwig <hch@lst.de>
G, GurucharanX Jan. 13, 2022, 5:57 p.m. UTC | #2 
> -----Original Message-----
> From: Intel-wired-lan <intel-wired-lan-bounces@osuosl.org> On Behalf Of
> Christophe JAILLET
> Sent: Sunday, January 9, 2022 10:51 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: netdev@vger.kernel.org; kernel-janitors@vger.kernel.org; linux-
> kernel@vger.kernel.org; Christophe JAILLET
> <christophe.jaillet@wanadoo.fr>; intel-wired-lan@lists.osuosl.org; Christoph
> Hellwig <hch@lst.de>
> Subject: [Intel-wired-lan] [PATCH] ixgbe: 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.
> 
> So, if dma_set_mask_and_coherent() succeeds, 'pci_using_dac' is known to
> be 1.
> 
> 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/ixgbe/ixgbe_main.c | 20 +++++++------------
>  1 file changed, 7 insertions(+), 13 deletions(-)
> 

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

Patch

diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
index 89b467006291..2c8a4a06f56a 100644
--- a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
+++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
@@ -10632,9 +10632,9 @@  static int ixgbe_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 	struct ixgbe_adapter *adapter = NULL;
 	struct ixgbe_hw *hw;
 	const struct ixgbe_info *ii = ixgbe_info_tbl[ent->driver_data];
-	int i, err, pci_using_dac, expected_gts;
 	unsigned int indices = MAX_TX_QUEUES;
 	u8 part_str[IXGBE_PBANUM_LENGTH];
+	int i, err, expected_gts;
 	bool disable_dev = false;
 #ifdef IXGBE_FCOE
 	u16 device_caps;
@@ -10654,16 +10654,11 @@  static int ixgbe_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 	if (err)
 		return err;
 
-	if (!dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(64))) {
-		pci_using_dac = 1;
-	} else {
-		err = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32));
-		if (err) {
-			dev_err(&pdev->dev,
-				"No usable DMA configuration, aborting\n");
-			goto err_dma;
-		}
-		pci_using_dac = 0;
+	err = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(64));
+	if (err) {
+		dev_err(&pdev->dev,
+			"No usable DMA configuration, aborting\n");
+		goto err_dma;
 	}
 
 	err = pci_request_mem_regions(pdev, ixgbe_driver_name);
@@ -10861,8 +10856,7 @@  static int ixgbe_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 		netdev->hw_features |= NETIF_F_NTUPLE |
 				       NETIF_F_HW_TC;
 
-	if (pci_using_dac)
-		netdev->features |= NETIF_F_HIGHDMA;
+	netdev->features |= NETIF_F_HIGHDMA;
 
 	netdev->vlan_features |= netdev->features | NETIF_F_TSO_MANGLEID;
 	netdev->hw_enc_features |= netdev->vlan_features;