Re: Mobility Radeon HD 4530/4570/545v: flicker in 1920x1080

From: Pavel Machek
Date: Thu Nov 05 2015 - 15:23:09 EST


Hi!

> >> The flickering would vanish completely if that's the reason for the issue
> >> you are seeing.
> >
> >> Try setting ref_div_min and ref_div_max to 2 in
> >> radeon_compute_pll_avivo().
> >
> > Ok, I did this, but no luck, still flickers. But the flicker only
> > happens when something changes on screen, like dragging a big
> > window. Is that consistent with wrong PLL timings?
>
> Does it go away with radeon.dpm=0? Sounds more like either memory
> reclocking happening outside of vblank, or underflow to the display
> controllers.

No, it does not:

pavel@half:~$ cat /proc/cmdline
BOOT_IMAGE=(hd0,2)/l/linux/arch/x86/boot/bzImage root=/dev/sda4
resume=/dev/sda1 radeon.dpm=0

..and same issue. And yes, it looks like an underflow to me. How can I
debug reclocking / underflows?

Best regards,
Pavel
--
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
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