[Bug 100885] [SNB] Blank screen after cycling HDMI receiver input

[bugzilla-daemon at freedesktop.org]

https://bugs.freedesktop.org/show_bug.cgi?id=100885

Lakshmi <lakshminarayana.vudum at intel.com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Priority|high                        |medium
             Status|NEW                         |NEEDINFO

--- Comment #21 from Lakshmi <lakshminarayana.vudum at intel.com> ---
(In reply to Matt Horan from comment #19)
> (In reply to Matt Horan from comment #18)
> > (In reply to Ville Syrjala from comment #17)
> > > We now have the properly to limite the bpc.
> > > 
> > > xrandr --output <whatever> --set 'max bpc' 8
> > > 
> > > Does that help?
> > 
> > Does this require a specific kernel version and/or xrandr version? Happy to
> > give it a shot.
> 
> I discovered that all that is needed is a kernel that supports the 'max bpc'
> prop, so I installed kernel 5.0.2. I successfully set max bpc to 8 when the
> display was working. However, when switching to another input and then back,
> the screen was blank. I could no longer set max bpc. xrandr --props showed
> max bpc of 12. If I tried to set max bpc to 8, the setting was seemingly
> ignored, and the screen remained blank.
> 
> I also tested with a newer Haswell machine, running both Windows and Linux.
> On Windows, I could not reproduce the issue. On Linux, I could not reproduce
> the issue as reliably, but it did occur. Interestingly, switching inputs a
> second time would resolve the issue. This is not a viable solution, however,
> as I do not plan to replace my SNB system any time soon (and something still
> seems broken.)
> 
> The only difference I noticed between Windows and Linux is that Windows
> never switched the display to 12bpc. I could not find an option in Windows
> to cause this to happen.

(In reply to James Ausmus from comment #20)
> Can you retest with drm-tip? There have been some changes around the max_bpc
> handling that may impact your situation

No feedback from more than a month. Dropping the Priority to Medium. 
Matt, Can you please provide your feedback after verifying the issue drm-tip
(https://cgit.freedesktop.org/drm-tip) ?

-- 
You are receiving this mail because:
You are the QA Contact for the bug.
You are on the CC list for the bug.
You are the assignee for the bug.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.freedesktop.org/archives/intel-gfx-bugs/attachments/20190719/41f2ae02/attachment.html>