[Intel-gfx] [PATCH 0/3] HDMI optimization series

[Daniel Vetter]

On Mon, Aug 10, 2015 at 04:50:37AM +0000, Jindal, Sonika wrote:
> Hi Daniel,
> 
> That patch was already merged:
> http://lists.freedesktop.org/archives/intel-gfx/2015-July/071142.html
> 
> For SKL, the above patch helped in getting the correct ISR bits set.
> One option is to enable the HDMI optimization from VLV onwards.
> I don't have an ivb machine to try out the issue.

ivb is simple the machine I have here, but when we tried this the last
time around we had reports for all platforms (your patch still doesn't
cite the relevant sha1 btw). I think there are 3 possible explanations:

a) we do something wrong with hpd handling on these platforms. That seems
to be the explanation you favour (with the gen >= 7 checks and all that),
but I think it's very unlikely: On each platform where we had reports of
hpd being broken there was also machines where hpd works perfectly fine.

b) There's broken HDMI (or DVI) sinks out there. If that's the case we can
never merge your patch.

c) There's something in vbt or somewhere else that tells the windows
driver whether using hpd or not is ok (and the hpd problem is actually an
issue with certain OEM machines ...).

I hoped that with your hpd handling fix we'd have some indication that our
hpd troubles are of type a). But since I tested with your patch that
didn't work out.

And until we have some evidence that our hpd troubles aren't type b) I
really don't want to merge any patch which relies upon hpd bits for hdmi.
-Daniel

> 
> Regards,
> Sonika
> 
> -----Original Message-----
> From: Daniel Vetter [mailto:daniel.vetter at ffwll.ch] On Behalf Of Daniel Vetter
> Sent: Friday, August 7, 2015 6:54 PM
> To: Jindal, Sonika
> Cc: intel-gfx at lists.freedesktop.org
> Subject: Re: [Intel-gfx] [PATCH 0/3] HDMI optimization series
> 
> On Tue, Jul 14, 2015 at 05:21:20PM +0530, Sonika Jindal wrote:
> > This series adds some optimization related to reading of edid only 
> > when required and when live status says so.
> > The comments in the patches explain more.
> 
> This series breaks my funky ivb machine with the broken hpd bits: When I unplug the screen the system never invalidates the edid and so never notices that it's gone.
> 
> Now iirc you've discovered an issue in our hpd irq handler which can cause lost hpd bits, but that patch isn't in this series. And iirc I asked you to resend everything since that hw fix also wasn't in the last series. And I can't find it any more. Did I just dream about this other patch to fix hpd on big core?
> 
> Thanks, Daniel
> 
> > v2:
> >    Some refactoring is with this series.
> > 
> >    Also, right now this is done for platforms gen7 and above because we
> >    couldn't test with older platforms. For newer platforms it works
> >    reliably.
> > 
> >    For HPD and live status to work on SKL, following patch is required:
> >    "drm/i915: Handle HPD when it has actually occurred"
> > 
> > Shashank Sharma (2):
> >   drm/i915: add attached connector to hdmi container
> >   drm/i915: Add HDMI probe function
> > 
> > Sonika Jindal (1):
> >   drm/i915: Check live status before reading edid
> > 
> >  drivers/gpu/drm/i915/intel_dp.c   |    4 +-
> >  drivers/gpu/drm/i915/intel_drv.h  |    3 ++
> >  drivers/gpu/drm/i915/intel_hdmi.c |   93 +++++++++++++++++++++++++++++++++----
> >  3 files changed, 88 insertions(+), 12 deletions(-)
> > 
> > --
> > 1.7.10.4
> > 
> > _______________________________________________
> > Intel-gfx mailing list
> > Intel-gfx at lists.freedesktop.org
> > http://lists.freedesktop.org/mailman/listinfo/intel-gfx
> 
> --
> Daniel Vetter
> Software Engineer, Intel Corporation
> http://blog.ffwll.ch

-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch