MT7621 Flow Control

[Jaap Buurman]

On Thu, Aug 6, 2020 at 2:35 PM John Crispin <john at phrozen.org> wrote:
>
>
> On 06.08.20 14:31, Andre Valentin wrote:
> > Hi Jaap,
> >
> >
> > Am 06.08.20 um 13:43 schrieb Jaap Buurman:
> >> Dear all,
> >>
> >> I have noticed the flow control work for mt7621 in the following
> >> Openwrt patch: https://git.openwrt.org/?p=openwrt/openwrt.git;a=commit;h=c8f8e59816eca49d776562d2d302bf990a87faf0
> >>
> >> However, the problem that the patch is supposed to fix is still
> >> occurring, even in combination with other experimental patches
> >> submitted. These experiences can be read about here:
> >> https://forum.openwrt.org/t/mtk-soc-eth-watchdog-timeout-after-r11573/50000/
> >>
> >> However, on this mailing list a user by the name of Kristian claims
> >> that disabling flow control helps fix this problem, as can be read
> >> here: https://lists.openwrt.org/pipermail/openwrt-devel/2017-November/009882.html
> >>
> >>  From what I understood, he was running many mt7621 devices
> >> commercially, with many of them experiencing the issue, which were all
> >> fixed with his own flow control patch. My question is why the decision
> >> was made to only disable flow control on port 5 in the above mentioned
> >> Openwrt patch? AFAIK, Kristian's own patch disables flow control on
> >> all of the ports and he claims the issue is fixed for him. Perhaps the
> >> current patch should be extended to disable flow control on all ports?
> >> What are people's thoughts on this?
> > I'm facing the same issue now after upgrading to 5.4 kernel more often than before.
> > Every second reboot reboot with 5.4 fails with this timeout error.
> >
> >> Yours sincerely,
> >>
> >> Jaap
> > André
> >
> >
> from previous discussions with MTK and looking at the SDK code, the flow
> control should always be disabled.
>
>      John
>

Dear John,

Thank you for your information! Does that mean the current patch might
be insufficient in the sense that it only disabled flow control on
port 5, rather than on all ports? Because as evident, people are still
facing the issue, that is supposedly fixed for Kristian, which used
his own patch to disable Flow Control on all ports. What is your
opinion on this?

Jaap