[PATCH] net/qla3xxx: Remove useless DMA-32 fallback configuration

[PATCH] net/qla3xxx: 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, '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>
---
This patch was not part of the 1st serie I've sent. So there is no
Reviewed-by tag.
---
 drivers/net/ethernet/qlogic/qla3xxx.c | 11 +++--------
 1 file changed, 3 insertions(+), 8 deletions(-)

diff --git a/drivers/net/ethernet/qlogic/qla3xxx.c b/drivers/net/ethernet/qlogic/qla3xxx.c
index 71523d747e93..b30589a135c2 100644
--- a/drivers/net/ethernet/qlogic/qla3xxx.c
+++ b/drivers/net/ethernet/qlogic/qla3xxx.c
@@ -3750,7 +3750,7 @@ static int ql3xxx_probe(struct pci_dev *pdev,
 	struct net_device *ndev = NULL;
 	struct ql3_adapter *qdev = NULL;
 	static int cards_found;
-	int pci_using_dac, err;
+	int err;
 
 	err = pci_enable_device(pdev);
 	if (err) {
@@ -3766,11 +3766,7 @@ static int ql3xxx_probe(struct pci_dev *pdev,
 
 	pci_set_master(pdev);
 
-	if (!dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(64)))
-		pci_using_dac = 1;
-	else if (!(err = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32))))
-		pci_using_dac = 0;
-
+	err = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(64));
 	if (err) {
 		pr_err("%s no usable DMA configuration\n", pci_name(pdev));
 		goto err_out_free_regions;
@@ -3797,8 +3793,7 @@ static int ql3xxx_probe(struct pci_dev *pdev,
 
 	qdev->msg_enable = netif_msg_init(debug, default_msg);
 
-	if (pci_using_dac)
-		ndev->features |= NETIF_F_HIGHDMA;
+	ndev->features |= NETIF_F_HIGHDMA;
 	if (qdev->device_id == QL3032_DEVICE_ID)
 		ndev->features |= NETIF_F_IP_CSUM | NETIF_F_SG;
 
-- 
2.32.0

Re: [PATCH] net/qla3xxx: 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 19:49:09 +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, 'pci_using_dac' is known to be
> 1.
> 
> [...]

Here is the summary with links:
  - net/qla3xxx: Remove useless DMA-32 fallback configuration
    https://git.kernel.org/netdev/net-next/c/0959a82ab3e5

You are awesome, thank you!
-- 
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