Re: Bug reports on 830MG patches (thanks, but more trouble)

Ville Syrjälä
2014-06-06T08:46:27Z

On Thu, Jun 05, 2014 at 11:33:55PM +0200, Thomas Richter wrote:
> Update on the 830MG Updates:
>
> As Ville already said, resume from "suspend-to-ram" is broken. No
> surprise, old broken bios. However, there is a big difference between
> the kernel with the pipe-A quirk disabled, and the one with pipe-a and
> pipe-b quirks enabled: If resumed without the quirk, the display is
> dead, but you can at least re-initiate it with vbetool post, then
> restart the X server. So at least, the kernel is working.
>
> With the pipe A quirk enabled, something dies immediately when
> attempting to resume from suspend. The machine is completely
> unresponsive, also not reachable over the network. The kernel dies away.

For me resume gets stuck even w/o i915. So something is different
clearly between our machines. Might be some driver, or might the BIOS.
Do you have the latest BIOS on that thing?

> This is *probably* related to the dying kernel when booting with vga=792
> (or vga=791 or vga=790, all cause the same problem, no working machine.)

I must admit I didn't try the vga= options. I'll give them a go and see
what happens.

>
> ----
>
> Thanks for the patch and for all the work, unfortunately it does not
> quite work as presented. I applied the patch correctly to
> drm-intel-nightly, and it compiles fine.

You applied all 15 patches, right?

>
> However, the following issues exist:
>
> *) If you boot with the kernel parameter vga=792 (i.e. the same console
> resolutions as initiated by KMS) the system just hangs with a black
> screen. Booting aborts, nothing happens.
>
> *) Watermark settings are *still* not correct. *SIGH*, *sigh*
>
> intel_reg_read 0x20d8
> 0x20D8 : 0x11F0104

I did warn you. If you'd just taken my branch you would have gotten the
hack to avoid that.

>
> This is a watermark level of 4. As I said multiple times, the watermark
> register needs to be *AT LEAST* eight (in numbers, 8) to have a stable
> display. It is stable between 8 and 32.
>
> To reproduce, use a panning display with xrandr:
>
> xrandr --output DVI1 --mode 1024x768 --panning 2048x1536
>
> then scroll, and see the display flicker.
>
> Folks, I really appreciate all your effort, but I would be really happy
> if my comments on the wrong watermarks wouldn't be continuously ignored.
> I submitted patches, twice, thrice... all went into the trash.
>
> Greetings,
> Thomas

--
Ville Syrjälä
Intel OTC