* [PATCH] cxgb4vf: Remove useless DMA-32 fallback configuration
@ 2022-01-09 13:59 Christophe JAILLET
2022-01-10 1:00 ` patchwork-bot+netdevbpf
0 siblings, 1 reply; 2+ messages in thread
From: Christophe JAILLET @ 2022-01-09 13:59 UTC (permalink / raw)
To: Raju Rangoju, David S. Miller, Jakub Kicinski
Cc: linux-kernel, kernel-janitors, Christophe JAILLET, netdev
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>
---
.../ethernet/chelsio/cxgb4vf/cxgb4vf_main.c | 20 +++++--------------
1 file changed, 5 insertions(+), 15 deletions(-)
diff --git a/drivers/net/ethernet/chelsio/cxgb4vf/cxgb4vf_main.c b/drivers/net/ethernet/chelsio/cxgb4vf/cxgb4vf_main.c
index acac2be0e3f0..7de3800437c9 100644
--- 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;
--
2.32.0
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH] cxgb4vf: Remove useless DMA-32 fallback configuration
2022-01-09 13:59 [PATCH] cxgb4vf: Remove useless DMA-32 fallback configuration Christophe JAILLET
@ 2022-01-10 1:00 ` patchwork-bot+netdevbpf
0 siblings, 0 replies; 2+ messages in thread
From: patchwork-bot+netdevbpf @ 2022-01-10 1:00 UTC (permalink / raw)
To: Christophe JAILLET
Cc: rajur, davem, kuba, linux-kernel, kernel-janitors, netdev
Hello:
This patch was applied to netdev/net-next.git (master)
by Jakub Kicinski <kuba@kernel.org>:
On Sun, 9 Jan 2022 14:59:48 +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:
- cxgb4vf: Remove useless DMA-32 fallback configuration
https://git.kernel.org/netdev/net-next/c/030f9ce8c739
You are awesome, thank you!
--
Deet-doot-dot, I am a bot.
https://korg.docs.kernel.org/patchwork/pwbot.html
^ permalink raw reply [flat|nested] 2+ messages in thread
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2022-01-10 1:00 ` patchwork-bot+netdevbpf
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