On 10/6/2021 10:00:16 AM, Stan Johnson <userm57@yahoo.com> wrote:
On 10/6/21 4:25 AM, John Paul Adrian Glaubitz wrote:
> On 10/6/21 01:40, Riccardo Mottola wrote:
>> Again, booting an old kernel leads to working X.
> Very much sounds like a kernel regression that you should bisect.
>
> That isn't too difficult when cross-building with a fast x86_64 machine.
>
> Adrian
>
I can confirm that X is not working on a PowerPC G4 Cube with the stock
Debian kernel "vmlinux-5.14.0-2-powerpc". X does work with the stock
Debian kernel "vmlinux-5.10.0-8-powerpc". In both cases, I'm using the
latest Debian SID with Xfce. In 5.14.0-2, wdm runs but the system
console screen remains blank (the LCD backlight is on).
(BTW, I have a PowerBook G4 12" 1.5GHz, but I didn't test the 5.14
kernel there. The PB G4 overheats and shuts off whenever it runs
anything CPU-intensive, such as a Gentoo upgrade or even compressing a
file. I think Apple had a way of throttling the CPU speed to prevent
overheating -- it doesn't have any problems with Mac OS X Tiger or
Leopard -- but they probably didn't share the details.)
I'll attempt a bisect, starting with mainline v5.14 and going backwards
if necessary (it looks like 5.12.9 worked; I'm not sure about v5.13). If
there's a kernel regression, I'll confirm the regression exists on both
the G4 Cube and the PB G4. I don't have an iBook to test.
-Stan