etnaviv-gpu 134000.gpu: MMU fault status 0x00000002 on i.XM6 Quad Plus

[Lucas Stach]

Am Mittwoch, den 30.08.2017, 11:20 +0100 schrieb Luís Mendes:
> 
> On Wed, Aug 30, 2017 at 10:56 AM, Lucas Stach <l.stach at pengutronix.de>
> wrote:
>         Am Mittwoch, den 30.08.2017, 10:46 +0100 schrieb Luís Mendes:
>         > Hi Lucas,
>         >
>         >
>         > I see in xf86-video-armada/etnaviv/etnaviv.c, that each of
>         the
>         > functions etnaviv_PolyLines,..., has a respective fallback
>         function
>         > call name unaccel_...
>         >
>         >
>         > When you say disable individual acceleration function, you
>         are saying
>         > to force the call to the respective unaccel function?
>         >
>         Yes, this way you should be able to narrow down which of the
>         acceleration functions is causing the GPU MMU faults. When you
>         have that
>         you can dump the parameters for all invocations of this
>         function, to
>         figure out why the GPU is accessing invalid memory regions.
>         
>  
> Ok, I'll try to do that as soon as I find some spare time.
> 
> 
> Regarding the screen blanking do you have a suggestion on how to debug
> it? I found that it is related with the prefetech unit enablement
> introduced in kernel 4.12.0, kernels 4.11.x do not exhibit such
> behaviour. What is happening is that when the X session is started for
> the login screen, sometimes the mouse arrow is seen for a second and
> then the screen blanks, sometimes the whole login screen can be seen
> for 10 seconds or so, and then either blanks or shows a corrupted
> screen image. Sometimes nothing is seen and screen just blanks before
> the X session starts.   

Make sure to use an upstream DT, where the PRE/PRG units are actually
used. The IPU driver will switch to using low-priority IPU channels when
it's on a QuadPlus IPU, which will starve the display when the PRG/PRE
units aren't set up correctly.

Regards,
Lucas