[PATCH] be2net: Remove useless DMA-32 fallback configuration

[PATCH] be2net: Remove useless DMA-32 fallback configuration

[Christophe JAILLET]

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, 'netdev->features' will have
NETIF_F_HIGHDMA in all cases. Move the assignment of this feature in
be_netdev_init() instead be_probe() which is a much logical place.

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>
---
 drivers/net/ethernet/emulex/benet/be_main.c | 14 +++++---------
 1 file changed, 5 insertions(+), 9 deletions(-)

diff --git a/drivers/net/ethernet/emulex/benet/be_main.c b/drivers/net/ethernet/emulex/benet/be_main.c
index 84b3ba9bdb18..d0c262f2695a 100644
--- a/drivers/net/ethernet/emulex/benet/be_main.c
+++ b/drivers/net/ethernet/emulex/benet/be_main.c
@@ -5194,7 +5194,8 @@ static void be_netdev_init(struct net_device *netdev)
 		netdev->hw_features |= NETIF_F_RXHASH;
 
 	netdev->features |= netdev->hw_features |
-		NETIF_F_HW_VLAN_CTAG_RX | NETIF_F_HW_VLAN_CTAG_FILTER;
+		NETIF_F_HW_VLAN_CTAG_RX | NETIF_F_HW_VLAN_CTAG_FILTER |
+		NETIF_F_HIGHDMA;
 
 	netdev->vlan_features |= NETIF_F_SG | NETIF_F_TSO | NETIF_F_TSO6 |
 		NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM;
@@ -5840,14 +5841,9 @@ static int be_probe(struct pci_dev *pdev, const struct pci_device_id *pdev_id)
 	SET_NETDEV_DEV(netdev, &pdev->dev);
 
 	status = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(64));
-	if (!status) {
-		netdev->features |= NETIF_F_HIGHDMA;
-	} else {
-		status = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32));
-		if (status) {
-			dev_err(&pdev->dev, "Could not set PCI DMA Mask\n");
-			goto free_netdev;
-		}
+	if (status) {
+		dev_err(&pdev->dev, "Could not set PCI DMA Mask\n");
+		goto free_netdev;
 	}
 
 	status = pci_enable_pcie_error_reporting(pdev);
-- 
2.32.0

Re: [PATCH] be2net: Remove useless DMA-32 fallback configuration

[patchwork-bot+netdevbpf]

Hello:

This patch was applied to netdev/net-next.git (master)
by Jakub Kicinski <kuba@kernel.org>:

On Sun,  9 Jan 2022 10:03:49 +0100 you wrote:
> 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, 'netdev->features' will have
> NETIF_F_HIGHDMA in all cases. Move the assignment of this feature in
> be_netdev_init() instead be_probe() which is a much logical place.
> 
> [...]

Here is the summary with links:
  - be2net: Remove useless DMA-32 fallback configuration
    https://git.kernel.org/netdev/net-next/c/942e78916f0c

You are awesome, thank you!
-- 
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