On Mon, Sep 20, 2021 at 10:55:31AM +0200, Maxime Ripard wrote:
> Hi,
> 
> On Sat, Sep 18, 2021 at 11:18:33AM +0200, Michael Stapelberg wrote:
> > torvalds at linux-foundation.org (Linus Torvalds) writes:
> > > Did I fix it up correctly? Who knows. The code makes more sense to me
> > > now and seems valid. But I really *really* want to stress how locking
> > > is important.
> > 
> > As far as I can tell, this merge conflict resolution made my Raspberry
> > Pi 3 hang on boot. You can find the full serial console output at:
> > 
> > https://t.zekjur.net/linux-5.14-raspberry-pi-3-hang-vc4.txt
> > 
> > The last few messages are from vc4, then the boot hangs.
> > 
> > Using git-bisect, I tracked this down to
> > https://github.com/torvalds/linux/commit/e058a84bfddc42ba356a2316f2cf1141974625c9,
> > which is the merge you’re talking about here, AFAICT.
> > 
> > I also tried the git://anongit.freedesktop.org/drm/drm, and that tree
> > boots as expected, suggesting that the problem really is with the
> > additional changes.
> > 
> > The code seems to work on my Raspberry Pi 4, just not on the Raspberry
> > Pi 3. Any ideas why that might be, and how to fix it?
> 
> I assume you run your Pi without anything connected on HDMI, and without
> hdmi_force_hotplug in your config.txt?
> 
> If so, can you test that branch, and let me know if it works for you
> https://github.com/mripard/linux/tree/rpi/bug-fixes

This breaks every one else, unfortunately. I'll try to come up with something.

Maxime