Aw: Re: [PATCH 0/3] Fix for KSZ DSA switch shutdown

[Lino Sanfilippo]

> Gesendet: Montag, 13. September 2021 um 12:44 Uhr
> Von: "Vladimir Oltean" <olteanv@xxxxxxxxx>
> An: "Lino Sanfilippo" <LinoSanfilippo@xxxxxx>
> Cc: "Andrew Lunn" <andrew@xxxxxxx>, "Florian Fainelli" <f.fainelli@xxxxxxxxx>, "Saravana Kannan" <saravanak@xxxxxxxxxx>, "Rafael J. Wysocki" <rafael@xxxxxxxxxx>, p.rosenberger@xxxxxxxxxx, woojung.huh@xxxxxxxxxxxxx, UNGLinuxDriver@xxxxxxxxxxxxx, vivien.didelot@xxxxxxxxx, davem@xxxxxxxxxxxxx, kuba@xxxxxxxxxx, netdev@xxxxxxxxxxxxxxx, linux-kernel@xxxxxxxxxxxxxxx
> Betreff: Re: [PATCH 0/3] Fix for KSZ DSA switch shutdown
>
> On Mon, Sep 13, 2021 at 12:32:14PM +0200, Lino Sanfilippo wrote:
> > Hi,
> >
> > > Gesendet: Sonntag, 12. September 2021 um 22:29 Uhr
> > > Von: "Vladimir Oltean" <olteanv@xxxxxxxxx>
> > > An: "Lino Sanfilippo" <LinoSanfilippo@xxxxxx>
> > > Cc: "Andrew Lunn" <andrew@xxxxxxx>, "Florian Fainelli" <f.fainelli@xxxxxxxxx>, "Saravana Kannan" <saravanak@xxxxxxxxxx>, "Rafael J. Wysocki" <rafael@xxxxxxxxxx>, p.rosenberger@xxxxxxxxxx, woojung.huh@xxxxxxxxxxxxx, UNGLinuxDriver@xxxxxxxxxxxxx, vivien.didelot@xxxxxxxxx, davem@xxxxxxxxxxxxx, kuba@xxxxxxxxxx, netdev@xxxxxxxxxxxxxxx, linux-kernel@xxxxxxxxxxxxxxx
> > > Betreff: Re: [PATCH 0/3] Fix for KSZ DSA switch shutdown
> > >
> > > On Sun, Sep 12, 2021 at 10:19:24PM +0200, Lino Sanfilippo wrote:
> > > >
> > > > Hi,
> > > >
> > > > On 10.09.21 at 16:58, Vladimir Oltean wrote:
> > > > > On Fri, Sep 10, 2021 at 01:51:56PM +0200, Andrew Lunn wrote:
> > > > >>> It does not really scale but we also don't have that many DSA masters to
> > > > >>> support, I believe I can name them all: bcmgenet, stmmac, bcmsysport, enetc,
> > > > >>> mv643xx_eth, cpsw, macb.
> > > > >>
> > > > >> fec, mvneta, mvpp2, i210/igb.
> > > > >
> > > > > I can probably double that list only with Freescale/NXP Ethernet
> > > > > drivers, some of which are not even submitted to mainline. To name some
> > > > > mainline drivers: gianfar, dpaa-eth, dpaa2-eth, dpaa2-switch, ucc_geth.
> > > > > Also consider that DSA/switchdev drivers can also be DSA masters of
> > > > > their own, we have boards doing that too.
> > > > >
> > > > > Anyway, I've decided to at least try and accept the fact that DSA
> > > > > masters will unregister their net_device on shutdown, and attempt to do
> > > > > something sane for all DSA switches in that case.
> > > > >
> > > > > Attached are two patches (they are fairly big so I won't paste them
> > > > > inline, and I would like initial feedback before posting them to the
> > > > > list).
> > > > >
> > > > > As mentioned in those patches, the shutdown ordering guarantee is still
> > > > > very important, I still have no clue what goes on there, what we need to
> > > > > do, etc.
> > > > >
> > > >
> > > > I tested these patches with my 5.10 kernel (based on Gregs 5.10.27 stable
> > > > kernel) and while I do not see the message "unregister_netdevice: waiting
> > > > for eth0 to become free. Usage count = 2." any more the shutdown/reboot hangs, too.
> > > > After a few attempts without any error messages on the console I was able to get a
> > > >  stack trace. Something still seems to go wrong in bcm2835_spi_shutdown() (see attachment).
> > > > I have not had the time yet to investigate this further (or to test the patches
> > > >  with a newer kernel).
> > >
> > > Could you post the full kernel output? The picture you've posted is
> > > truncated and only shows a WARN_ON in rpi_firmware_transaction and is
> > > probably a symptom and not the issue (which is above and not shown).
> > >
> >
> > Unfortunately I dont see anything in the kernel log. The console output is all I get,
> > thats why I made the photo.
>
> To clarify, are you saying nothing above this line gets printed? Because
> the part of the log you've posted in the picture is pretty much
> unworkable:
>
> [   99.375389] [<bf0dc56c>] (bcm2835_spi_shutdown [spi_bcm2835]) from [<c0863ca0>] (platform_drv_shutdown+0x2c/0x30)
>
> How do you access the device's serial console? Use a program with a
> scrollback buffer like GNU screen or something.
>

Ah no, this is not over a serial console. This is what I see via hdmi. I do not have a working serial connection yet.
Sorry I know this trace part is not very useful, I will try to get a full dump.