[PATCH] cxgb3: Remove useless DMA-32 fallback configuration

From: Christophe JAILLET
Date: Sun Jan 09 2022 - 08:51:51 EST


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@xxxxxxxxxx>
---
drivers/net/ethernet/chelsio/cxgb3/cxgb3_main.c | 11 +++++------
1 file changed, 5 insertions(+), 6 deletions(-)

diff --git a/drivers/net/ethernet/chelsio/cxgb3/cxgb3_main.c b/drivers/net/ethernet/chelsio/cxgb3/cxgb3_main.c
index e2637bd2f423..63521312cb90 100644
--- a/drivers/net/ethernet/chelsio/cxgb3/cxgb3_main.c
+++ b/drivers/net/ethernet/chelsio/cxgb3/cxgb3_main.c
@@ -3204,7 +3204,7 @@ static void cxgb3_init_iscsi_mac(struct net_device *dev)
NETIF_F_IPV6_CSUM | NETIF_F_HIGHDMA)
static int init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
{
- int i, err, pci_using_dac = 0;
+ int i, err;
resource_size_t mmio_start, mmio_len;
const struct adapter_info *ai;
struct adapter *adapter = NULL;
@@ -3231,9 +3231,8 @@ static int init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
goto out_disable_device;
}

- if (!dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(64))) {
- pci_using_dac = 1;
- } else if ((err = dma_set_mask(&pdev->dev, DMA_BIT_MASK(32))) != 0) {
+ err = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(64));
+ if (err) {
dev_err(&pdev->dev, "no usable DMA configuration\n");
goto out_release_regions;
}
@@ -3309,8 +3308,8 @@ static int init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
netdev->features |= netdev->hw_features |
NETIF_F_HW_VLAN_CTAG_TX;
netdev->vlan_features |= netdev->features & VLAN_FEAT;
- if (pci_using_dac)
- netdev->features |= NETIF_F_HIGHDMA;
+
+ netdev->features |= NETIF_F_HIGHDMA;

netdev->netdev_ops = &cxgb_netdev_ops;
netdev->ethtool_ops = &cxgb_ethtool_ops;
--
2.32.0