Re: radeon: Regression between v3.6-rc4 and v3.6-rc6: unable toallocate a PPLL

From: Alex Deucher
Date: Thu Sep 27 2012 - 12:19:48 EST


On Thu, Sep 27, 2012 at 10:54 AM, Alex Deucher <alexdeucher@xxxxxxxxx> wrote:
> On Thu, Sep 27, 2012 at 9:23 AM, Andres Freund <andres@xxxxxxxxxxx> wrote:
>> On Thursday, September 27, 2012 03:14:31 PM Alex Deucher wrote:
>>> On Thu, Sep 27, 2012 at 2:46 AM, Andres Freund <andres@xxxxxxxxxxx> wrote:
>>> > On Wednesday, September 26, 2012 03:42:40 PM Deucher, Alexander wrote:
>>> >> > -----Original Message-----
>>> >> > From: Andres Freund [mailto:andres@xxxxxxxxxxx]
>>> >> > Sent: Wednesday, September 26, 2012 9:41 AM
>>> >> > To: Dan Carpenter
>>> >> > Cc: Deucher, Alexander; LKML; David Airlie;
>>> >> > dri-devel@xxxxxxxxxxxxxxxxxxxxx Subject: Re: radeon: Regression
>>> >> > between v3.6-rc4 and v3.6-rc6: unable to allocate a PPLL
>>> >> >
>>> >> > On Wednesday, September 26, 2012 03:00:09 PM Dan Carpenter wrote:
>>> >> > > This is fixed now?
>>> >> >
>>> >> > Its been reverted in 2f1f4d9b60396d2df4cff829bd5376ffc8ed9a2c which is
>>> >> > in rc6.
>>> >> >
>>> >> > On Monday, September 17, 2012 09:30:12 PM Deucher, Alexander wrote:
>>> >> > Sorry, I somehow accidentally marked your email as read and thus
>>> >> > didn't notice it.
>>> >> >
>>> >> > > I think I see the problem. I think it's a limitation of the current
>>> >> > > current
>>> >> >
>>> >> > modesetting API. The current API sets up each display independently
>>> >> > which doesn't work so well if there are resource restrictions. There
>>> >> > shouldn't be any contention on your board since you are only using 2
>>> >> > non-DP displays. It looks like X is mapping different crtcs to
>>> >> > displays than the kernel fb.
>>> >> >
>>> >> > Initially the kernel set up the follow:
>>> >> > > > [ 2.134901] [drm] crtc 0 using pll 0x2
>>> >> > > > [ 2.362257] [drm] crtc 1 using pll 0x1
>>> >> > > > [ 2.386709] [drm] crtc 2 using pll 0x0
>>> >> > >
>>> >> > > Crtc 0 -> DCPLL -> DP
>>> >> > > Crtc 1 -> PPLL2 -> DVI
>>> >> > > Crtc 2 -> PPLL1 -> DVI
>>> >> > >
>>> >> > > When X loads, it tried to set a different crtc to display mapping:
>>> >> > > > [ 60.679310] [drm] crtc 0 using pll 0xff
>>> >> > > > [ 60.789183] [drm] crtc 1 using pll 0x2
>>> >> > > > [ 60.819594] [drm] crtc 2 using pll 0x1
>>> >> > >
>>> >> > > Crtc 0 -> INVALID -> DVI 0
>>> >> > > Crtc 1 -> DCPLL -> DP
>>> >> > > Crtc 2 -> PPLL2 -> DVI 1
>>> >> > >
>>> >> > > Crtc 0 should have used PPLL1 or PPLL2, but they were already in use
>>> >> > > by crtc 1 and crtc 2 from the previous modeset. Since the modeset
>>> >> > > API is not atomic, it doesn't have the whole picture. I'm not sure
>>> >> > > of a good solution right now prior to the new atomic modeset API
>>> >> > > that is under discussion. I guess we can revert the patch for 3.6.
>>> >> > > For 3.7 I guess we need to validate the actual connector to make
>>> >> > > sure we aren't trying to set a different configuration relating to
>>> >> > > the same connector without first tearing down the first one. In
>>> >> > > the interim, you should be able to work around it by disabling the
>>> >> > > non-DP outputs and then bringing than back up.
>>> >> >
>>> >> > Thanks! That explanation makes sense. I can work around it just fine,
>>> >> > starting X multiple times works which coincides nicely with your
>>> >> > explanation.
>>> >> >
>>> >> > The code in the 3.7 branch doesn't do that extended validation yet,
>>> >> > rigth? If you want/need you can CC for testing once thats ready.
>>> >>
>>> >> It should handle it now. If you could test it that would be great.
>>> >
>>> > Ok, just to be sure I tested Linus' tree and everything works fine there.
>>> >
>>> > Unfortunately thats not the case with a straight merge of
>>> > alexdeucher/drm- next-3.7-wip. When gdm started *the first time* the
>>> > DVI-connected (uhm, same sink type? Thats the saphire magic allowing
>>> > more monitors on that type of graphics card?) I got a "unable to
>>> > allocate a PPLL" error again. Logging in/starting a new X seems to fix
>>> > that.
>>>
>>> So you have a xorg.conf with a hardcoded configuration? If so can you
>>> send it to me?
>> Yes, but just setting the xrand positions:
>
> Thanks. I can't seem to reproduce it here, but I've pushed an updated
> drm-next-3.7-wip which may help. If not, can you apply the attached
> patch and send me the output?

Ok, I was finally able to reproduce your issue and it's working fine
here with my latest drm-next-3.7-wip branch.

Alex
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