diff mbox series

[4/5] net: mvneta: enable NETIF_F_RXCSUM by default

Message ID 20180829162932.6015e89d@xhacker.debian
State Changes Requested, archived
Delegated to: David Miller
Headers show
Series net: mvneta: some bug fix and trivial improvement | expand

Commit Message

Jisheng Zhang Aug. 29, 2018, 8:29 a.m. UTC
The code and HW supports NETIF_F_RXCSUM, so let's enable it by default.

Signed-off-by: Jisheng Zhang <Jisheng.Zhang@synaptics.com>
---
 drivers/net/ethernet/marvell/mvneta.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

Comments

Gregory CLEMENT Aug. 29, 2018, 9:38 a.m. UTC | #1
Hi Jisheng,
 
 On mer., août 29 2018, Jisheng Zhang <Jisheng.Zhang@synaptics.com> wrote:

> The code and HW supports NETIF_F_RXCSUM, so let's enable it by
> default.

Same as the previous one, it should go to net-next and

Reviewed-by: Gregory CLEMENT <gregory.clement@bootlin.com>

Thanks,

Gregory


>
> Signed-off-by: Jisheng Zhang <Jisheng.Zhang@synaptics.com>
> ---
>  drivers/net/ethernet/marvell/mvneta.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/net/ethernet/marvell/mvneta.c b/drivers/net/ethernet/marvell/mvneta.c
> index 06634d4f9b94..7d98f7828a30 100644
> --- a/drivers/net/ethernet/marvell/mvneta.c
> +++ b/drivers/net/ethernet/marvell/mvneta.c
> @@ -4591,7 +4591,8 @@ static int mvneta_probe(struct platform_device *pdev)
>  		}
>  	}
>  
> -	dev->features = NETIF_F_SG | NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM | NETIF_F_TSO;
> +	dev->features = NETIF_F_SG | NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM |
> +			NETIF_F_TSO | NETIF_F_RXCSUM;
>  	dev->hw_features |= dev->features;
>  	dev->vlan_features |= dev->features;
>  	dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
> -- 
> 2.18.0
>
>
> _______________________________________________
> linux-arm-kernel mailing list
> linux-arm-kernel@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
Andrew Lunn Aug. 29, 2018, 1:08 p.m. UTC | #2
On Wed, Aug 29, 2018 at 04:29:32PM +0800, Jisheng Zhang wrote:
> The code and HW supports NETIF_F_RXCSUM, so let's enable it by default.

Hi Jisheng

I've never studied what all these different flags mean. Does
NETIF_F_RXCSUM mean Ethernet FCS? Or does it also include IPv4, IPv6,
UDP, TCP... checksums?

I've seen network interfaces get checksum'ing wrong when used with an
Ethernet switch with DSA. The extra header DSA uses means the hardware
cannot parse the packet correctly, and so cannot find these headers.

If this is just for FCS, then it is not a problem.

   Thanks
	Andrew
Jisheng Zhang Aug. 30, 2018, 3:27 a.m. UTC | #3
Hi Andrew,

On Wed, 29 Aug 2018 15:08:36 +0200 Andrew Lunn wrote:

> On Wed, Aug 29, 2018 at 04:29:32PM +0800, Jisheng Zhang wrote:
> > The code and HW supports NETIF_F_RXCSUM, so let's enable it by default.  
> 
> Hi Jisheng
> 
> I've never studied what all these different flags mean. Does
> NETIF_F_RXCSUM mean Ethernet FCS? Or does it also include IPv4, IPv6,
> UDP, TCP... checksums?

Per my understanding, it means RX checksumming. And it only supports IPv4
RX checksum, the code will

> 
> I've seen network interfaces get checksum'ing wrong when used with an
> Ethernet switch with DSA. The extra header DSA uses means the hardware
> cannot parse the packet correctly, and so cannot find these headers.

The network interface is mvneta? Do you mean after this patch, we would
see errors as the following?

"bad rx status 0xabcdefgh (crc error)"

So for DSA, we should disable RXCSUM? I'm not sure how to handle this case.
I believe other drivers(with RXCSUM enabled by deafult) also have this problem
with DSA.

Thanks

> 
> If this is just for FCS, then it is not a problem.
> 
>    Thanks
> 	Andrew
> 
> _______________________________________________
> linux-arm-kernel mailing list
> linux-arm-kernel@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
Andrew Lunn Aug. 30, 2018, 3:44 a.m. UTC | #4
> > I've seen network interfaces get checksum'ing wrong when used with an
> > Ethernet switch with DSA. The extra header DSA uses means the hardware
> > cannot parse the packet correctly, and so cannot find these headers.
> 
> The network interface is mvneta?

I've not tested mvneta yet. It could be, since it was designed to be
used with Marvell switches in things like WiFi boxes, it knows how to
find the IP header when there is a DSA tag.

> Do you mean after this patch, we would see errors as the following?
> 
> "bad rx status 0xabcdefgh (crc error)"

I've not tried it yet. That is why i'm trying to understand what
NETIF_F_RXCSUM actually means.

       Andrew
diff mbox series

Patch

diff --git a/drivers/net/ethernet/marvell/mvneta.c b/drivers/net/ethernet/marvell/mvneta.c
index 06634d4f9b94..7d98f7828a30 100644
--- a/drivers/net/ethernet/marvell/mvneta.c
+++ b/drivers/net/ethernet/marvell/mvneta.c
@@ -4591,7 +4591,8 @@  static int mvneta_probe(struct platform_device *pdev)
 		}
 	}
 
-	dev->features = NETIF_F_SG | NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM | NETIF_F_TSO;
+	dev->features = NETIF_F_SG | NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM |
+			NETIF_F_TSO | NETIF_F_RXCSUM;
 	dev->hw_features |= dev->features;
 	dev->vlan_features |= dev->features;
 	dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;