etnaviv fails probe early, but succeeds after rmmod && modprobe

[Ing. Josua Mayer]

Hi Lucas,

anatop_regulator is indeed a module currently,
this is one of the changes introduced in their jump from kernel 5.9 to 
5.10 - and has even landed in buster through backports ...

I wonder how / where those timeouts are specified.
Regarding the order of module loading there is not much I can do, it is 
already the second module inserted by the initramfs.

sincerely
Josua Mayer

Am 16.04.21 um 12:41 schrieb Lucas Stach:
> Hi Josua,
> 
> Am Freitag, dem 16.04.2021 um 11:34 +0200 schrieb Ing. Josua Mayer:
>> Greetings everybody,
>>
>> While testing Debian on the i.MX6 HummingBoard, I came across a problem
>> where after boot, the /dev/dri/card1 representing the GC2000 does not exist.
>>
>> However at that point issuing
>> rmmod etnaviv; modprobe etnaviv
>> succeeds and I can then go on running applications uing GL.
>>
>> So I am very unsure how to debug this. What I have so far is this output
>> from dmesg [1], which points at some deferred probing timeout behaviour.
>> I do not know how to trace
>> (1) whose timeout exceeded
>> (2) what dependency is being ignored
>> (3) why after 3 attempts probing apparently gives up
>> I do know that this problem is shared with the coda driver, which fails
>> the same way. Hence maybe this is not an etnaviv problem - but hopefully
>> this message can still reach somebody who understands what is happening
>> here.
> 
> I have no idea how this deferred probe timeout stuff works, but from
> your logs it seems vddpu gets probed really late (is the anatop
> regulator driver a module in your config?), which in turn would cause a
> probe defer of the GPC power domain driver, which is a common
> dependency between VPU and GPU on the i.MX6. Seems like those etnaviv
> timeouts happen before the GPC driver had a chance to probe.
> 
> Regards,
> Lucas
> 
> 
>> Yours sincerely
>> Josua Mayer
>>
>> [1] short dmesg (full dmesg attached):
>> root at sr-imx6:~# dmesg | grep etna
>> [    5.969888] etnaviv-gpu 130000.gpu: deferred probe timeout, ignoring
>> dependency
>> [    5.985970] etnaviv-gpu: probe of 130000.gpu failed with error -110
>> [    6.076604] etnaviv-gpu 134000.gpu: deferred probe timeout, ignoring
>> dependency
>> [    6.102833] etnaviv-gpu: probe of 134000.gpu failed with error -110
>> [    6.121231] etnaviv-gpu 2204000.gpu: deferred probe timeout, ignoring
>> dependency
>> [    6.150314] etnaviv-gpu: probe of 2204000.gpu failed with error -110
>> root at sr-imx6:~# rmmod etnaviv
>> root at sr-imx6:~# modprobe etnaviv
>> root at sr-imx6:~# dmesg | grep etna
>> ...
>> [  166.482349] etnaviv etnaviv: bound 130000.gpu (ops gpu_ops [etnaviv])
>> [  166.502064] etnaviv etnaviv: bound 134000.gpu (ops gpu_ops [etnaviv])
>> [  166.514261] etnaviv etnaviv: bound 2204000.gpu (ops gpu_ops [etnaviv])
>> [  166.520868] etnaviv-gpu 130000.gpu: model: GC2000, revision: 5108
>> [  166.527630] etnaviv-gpu 134000.gpu: model: GC320, revision: 5007
>> [  166.533879] etnaviv-gpu 2204000.gpu: model: GC355, revision: 1215
>> [  166.540048] etnaviv-gpu 2204000.gpu: Ignoring GPU with VG and FE2.0
>> [  166.547379] [drm] Initialized etnaviv 1.3.0 20151214 for etnaviv on
>> minor 1
>> _______________________________________________
>> etnaviv mailing list
>> etnaviv at lists.freedesktop.org
>> https://lists.freedesktop.org/mailman/listinfo/etnaviv
> 
>