Commit 030f9ce8 authored by Christophe JAILLET's avatar Christophe JAILLET Committed by Jakub Kicinski
Browse files

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: default avatarChristophe JAILLET <christophe.jaillet@wanadoo.fr>
Link: https://lore.kernel.org/r/b14986ea39cea2ca9a6cd0476a3fc167c853ee67.1641736772.git.christophe.jaillet@wanadoo.fr


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 7fc7fc5d

drivers/net/ethernet/chelsio/cxgb4vf/cxgb4vf_main.c

+5 −15
Original line number Diff line number Diff line
@@ -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;



	/*
@@ -2920,20 +2919,13 @@ 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) {

	if (err) {

		dev_err(&pdev->dev, "no usable DMA configuration\n");

		goto err_release_regions;

	}

		pci_using_dac = 0;

	}



	/*

	 * Enable bus mastering for the device ...
@@ -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;