Re: [Bug Report] Depmod is failing on allmodconfig for arm64 and x86_64

[Daniel Machon]

Hi Calvin, Muhammad,

Thanks for reporting this.

Took me a while to reproduce, turned out i needed a newer version of kmod in
order to get the error print.

> On Tuesday 11/26 at 18:25 +0500, Muhammad Usama Anjum wrote:
> > Hi,
> >
> > The depmod is failing on 9f16d5e6f2206 (mainline) arm64 and x86_64 because of:
> > ```
> > depmod: ERROR: Cycle detected: libphy
> >
> > depmod: ERROR: Cycle detected: lan969x_switch -> sparx5_switch -> lan969x_switch
> > depmod: ERROR: Cycle detected: ptp
> > depmod: ERROR: Cycle detected: stp
> > depmod: ERROR: Cycle detected: ipv6
> > depmod: ERROR: Cycle detected: bridge
> > depmod: ERROR: Found 2 modules in dependency cycles!
> > make[2]: *** [scripts/Makefile.modinst:132: depmod] Error 1
> > make[1]: *** [/tmp/kci/linux/Makefile:1844: modules_install] Error 2
> > make: *** [Makefile:224: __sub-make] Error 2
> > ```
> >
> > This issue wasn't present until c66fbc6c3df9.
> 
> I set up a bisect script to run overnight, it landed here:
> 
>     98a01119608d21e0ed95a544071beabb353240ed is the first bad commit
>     commit 98a01119608d21e0ed95a544071beabb353240ed
>     Author:     Daniel Machon <daniel.machon@xxxxxxxxxxxxx>
>     AuthorDate: Thu Oct 24 00:01:33 2024 +0200
>     Commit:     Jakub Kicinski <kuba@xxxxxxxxxx>
>     CommitDate: Wed Oct 30 18:08:06 2024 -0700
> 
>         net: sparx5: add compatible string for lan969x
> 
>         Add lan9691-switch compatible string to mchp_sparx5_match. Guard it with
>         IS_ENABLED(CONFIG_LAN969X_SWITCH) to make sure Sparx5 can be compiled on
>         its own.
> 
>         Reviewed-by: Steen Hegelund <Steen.Hegelund@xxxxxxxxxxxxx>
>         Signed-off-by: Daniel Machon <daniel.machon@xxxxxxxxxxxxx>
>         Link: https://patch.msgid.link/20241024-sparx5-lan969x-switch-driver-2-v2-14-a0b5fae88a0f@xxxxxxxxxxxxx
>         Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx>
> 
>      drivers/net/ethernet/microchip/sparx5/sparx5_main.c | 5 +++++
>      1 file changed, 5 insertions(+)
>     bisect found first bad commit
> 
> Thanks,
> Calvin

So we have two modules: sparx5-switch.ko and lan969x-switch.ko. They both
require symbols from each other, so the error makes sense.  I think the
solution here is to just ditch the lan969x-switch.ko module alltogether and
compile the support into the sparx5-switch.ko module.

/Daniel