Re: [PATCH RFC 6/6] net/faraday: Enable offload checksum according to device-tree

On Mon, Nov 09, 2015 at 11:36:10AM +1100, Benjamin Herrenschmidt wrote:

On Mon, 2015-11-09 at 11:10 +1100, Gavin Shan wrote:

quoted

This enables IP/UDP/TCP offload checksum according to information
passed on from bootloader through device-tree. The offload doesn't
working properly when the interface works in NCSI mode.

Signed-off-by: Gavin Shan <redacted>
---
 drivers/net/ethernet/faraday/ftgmac100.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/faraday/ftgmac100.c b/drivers/net/ethernet/faraday/ftgmac100.c
index 1b13fd4..1e2f4d2 100644
--- a/drivers/net/ethernet/faraday/ftgmac100.c
+++ b/drivers/net/ethernet/faraday/ftgmac100.c

@@ -1377,7 +1377,10 @@ static int ftgmac100_probe(struct platform_device *pdev)

 
 > 	> netdev->ethtool_ops = &ftgmac100_ethtool_ops;
 > 	> netdev->netdev_ops = &ftgmac100_netdev_ops;
-> 	> netdev->features = NETIF_F_IP_CSUM | NETIF_F_GRO;
+> 	> netdev->features = NETIF_F_GRO;
+> 	> if (pdev->dev.of_node &&
+> 	>     of_property_read_bool(pdev->dev.of_node, "no-hw-checksum"))
+> 	> 	> netdev->features |= NETIF_F_IP_CSUM;

Am I reading properly that if you put "no-hw-checksum" in the device-
tree you *enable* HW checksum ? This doesn't look right to me...

The logic should be:

if (pdev->dev.of_node &&
	of_property_read_bool(pdev->dev.of_node, "no-hw-checksum"))
	netdev->features &= ~NETIF_F_IP_CSUM;

Thanks, Ben. You're right. This flag affects TCP flows and I didn't test
it with this series of patchset. I'll adjust the code accordingly in next
respin.

Thanks,
Gavin