Re: framebuffer corruption due to overlapping stp instructions on arm64

From: Mikulas Patocka
Date: Tue Aug 07 2018 - 14:17:39 EST




On Tue, 7 Aug 2018, Ard Biesheuvel wrote:

> On 7 August 2018 at 19:39, Mikulas Patocka <mpatocka@xxxxxxxxxx> wrote:
> >
> >
> > On Tue, 7 Aug 2018, Marcin Wojtas wrote:
> >
> >> Ard, Mikulas,
> >>
> >> After some self-caused setup issues I was able to run the test on my
> >> MacchiatoBin with the kernel v4.18-rc8. It's been running for 1h+ now,
> >> loading the CPU to 100% and no single error event...
> >>
> >> I built the binary file with:
> >> gcc-linaro-7.2.1-2017.11-x86_64_aarch64-linux-gnu/bin/aarch64-linux-gnu-gcc -O2
> >>
> >> Maybe it's the older firmware issue?
> >
> > I have downloaded and built the firmware recently (it has timestamp Jul 30
> > 2018).
> >
> > Do you still have your firmware file "flash-image.bin" that you used, so
> > that I could try it?
> >
> >> Please send the full bootlog with
> >> the very first line after reset. My board rev is v1.3 and I use
> >> mainline UEFI (newest edk2 + edk2-platforms) + newest publicly
> >> available ARM-TF and earliest firmware for this board.
> >>
> >> Best regards,
> >> Marcin
> >
>
> Mikulas,
>
> Is the issue reproducible with an nvidia card + nouveau driver as well ?
>
> Given the screen corruption i see with radeon even on other arm
> systems, i'd like to ensure that this is a platform bug not a driver
> bug.

I see the same memcpy-to-framebuffer corruption on Radeon HD 6450 and
nVidia Quadro NVS 285.

3D acceleration on nVidia is slow, but it doesn't have visible glitches.

Mikulas