Re: [PATCH] gianfar: fix bug caused by 87c288c6e9aa31720b72e2bc2d665e24e1653c3e

[Jiri Pirko <jpirko@redhat.com>]

Tue, Jul 26, 2011 at 01:13:41PM CEST, sebastian.belden@googlemail.com wrote:
>Am Dienstag, den 26.07.2011, 12:46 +0200 schrieb Jiri Pirko:
>> Tue, Jul 26, 2011 at 12:03:13PM CEST, sebastian.belden@googlemail.com wrote:
>> >commit 87c288c6e9aa31720b72e2bc2d665e24e1653c3e "gianfar: do vlan cleanup" has two issues:
>> ># permutation of rx and tx flags
>> ># enabling vlan tag insertion by default (this leads to unusable connections on some configurations)
>> 
>> How so? What's causing that?
>If you enable the VLINS bit of txctrl and do not alter the vlan tag
>configuration of the NIC, every packet will get a all zero vlan tag
>(0x8100 0000). If you run a network without vlan awareness all packets
>will be ignored.


Interesting hw... I would guess that if gfar_tx_vlan() is not called, no
tag would be put there...

>
>In my configuration gianfar system <-> 3c59x system the 3com system
>discards all packets received with the vlan tag.
>> 
>> >
>> >If VLAN insertion is requested (via ethtool) it will be set at an other point ...
>> >
>> >Signed-off-by: Sebastian Poehn <sebastian.poehn@belden.com>
>> >---
>> >
>> > drivers/net/gianfar.c |    6 +-----
>> > 1 files changed, 1 insertions(+), 5 deletions(-)
>> >
>> >diff --git a/drivers/net/gianfar.c b/drivers/net/gianfar.c
>> >index 835cd25..2659daa 100644
>> >--- a/drivers/net/gianfar.c
>> >+++ b/drivers/net/gianfar.c
>> >@@ -388,12 +388,8 @@ static void gfar_init_mac(struct net_device *ndev)
>> > 	if (priv->hwts_rx_en)
>> > 		rctrl |= RCTRL_PRSDEP_INIT | RCTRL_TS_ENABLE;
>> > 
>> >-	/* keep vlan related bits if it's enabled */
>> >-	if (ndev->features & NETIF_F_HW_VLAN_TX)
>> >-		rctrl |= RCTRL_VLEX | RCTRL_PRSDEP_INIT;
>> >-
>> > 	if (ndev->features & NETIF_F_HW_VLAN_RX)
>> >-		tctrl |= TCTRL_VLINS;
>> >+		rctrl |= RCTRL_VLEX | RCTRL_PRSDEP_INIT;
>> > 
>> > 	/* Init rctrl based on our settings */
>> > 	gfar_write(&regs->rctrl, rctrl);
>> >
>> >
>> 
>> If you really need that to be done, you should remove NETIF_F_HW_VLAN_TX
>> from features (not hw_features) (never add it).
>> 
>The only thing I did is to let the vlan insertion disabled by default.
>If someone wants it, it may be enabled via ethtool.
>
>