cxgb4vf: 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>
Link: https://lore.kernel.org/r/b14986ea39cea2ca9a6cd0476a3fc167c853ee67.1641736772.git.christophe.jaillet@wanadoo.fr
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/drivers/net/ethernet/chelsio/cxgb4vf/cxgb4vf_main.c b/drivers/net/ethernet/chelsio/cxgb4vf/cxgb4vf_main.c
index acac2be0e3f02948fb7fdeff26d864bf8c81ff4c..7de3800437c95d7ce64c058ecbd15d892d623d69 100644 (file)
--- a/drivers/net/ethernet/chelsio/cxgb4vf/cxgb4vf_main.c
+++ b/drivers/net/ethernet/chelsio/cxgb4vf/cxgb4vf_main.c
@@ -2899,7 +2899,6 @@ static int cxgb4vf_pci_probe(struct pci_dev *pdev,
        struct net_device *netdev;
        struct port_info *pi;
        unsigned int pmask;
-       int pci_using_dac;
        int err, pidx;
 
        /*
@@ -2920,19 +2919,12 @@ static int cxgb4vf_pci_probe(struct pci_dev *pdev,
        }
 
        /*
-        * Set up our DMA mask: try for 64-bit address masking first and
-        * fall back to 32-bit if we can't get 64 bits ...
+        * Set up our DMA mask
         */
        err = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(64));
-       if (err == 0) {
-               pci_using_dac = 1;
-       } else {
-               err = dma_set_mask(&pdev->dev, DMA_BIT_MASK(32));
-               if (err != 0) {
-                       dev_err(&pdev->dev, "no usable DMA configuration\n");
-                       goto err_release_regions;
-               }
-               pci_using_dac = 0;
+       if (err) {
+               dev_err(&pdev->dev, "no usable DMA configuration\n");
+               goto err_release_regions;
        }
 
        /*
@@ -3078,9 +3070,7 @@ static int cxgb4vf_pci_probe(struct pci_dev *pdev,
                netdev->hw_features = NETIF_F_SG | TSO_FLAGS | NETIF_F_GRO |
                        NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM | NETIF_F_RXCSUM |
                        NETIF_F_HW_VLAN_CTAG_TX | NETIF_F_HW_VLAN_CTAG_RX;
-               netdev->features = netdev->hw_features;
-               if (pci_using_dac)
-                       netdev->features |= NETIF_F_HIGHDMA;
+               netdev->features = netdev->hw_features | NETIF_F_HIGHDMA;
                netdev->vlan_features = netdev->features & VLAN_FEAT;
 
                netdev->priv_flags |= IFF_UNICAST_FLT;