[mythtv-users] Can't start mythfrontend with TV off since moving to Intel graphics

Paul Gardiner lists at glidos.net
Wed Oct 28 08:51:44 UTC 2020


Thanks for looking. I can see that it might not be feasible to 
workaround it cleanly if there is no way to create a valid QScreen for a 
disconnected display.

Given that the intel driver is open source, I'm wondering about adding 
to it support for the ConnectedMonitor option, but I imagine the source 
may frighten the hell out of me.

On 27/10/2020 21:53, Mark Kendall wrote:
> Paul
> 
> OK - I see what is happening (the root cause is that the display is
> not connected)
> 
> Firstly, Qt isn't sure what display it is connected to which leads to
> this line in the logs (I'd have to check but presumably Qt ignores
> displays that are reported as disconnected):-
> 
> mythdisplay.cpp:376 (GetDesiredScreen) - Display: Screen 'HDMI1' not
> found, defaulting to primary screen (:0.0)
> 
> The mythtv code then tries to match :0.0 to a known display, and fails
> with this line:-
> 
> platforms/mythdisplayx11.cpp:125 (GetVideoModes) - DisplayX11: Failed
> to find an output that matches ':0.0'
> 
> and actually even if it tried searching for HDMI1 instead, it would
> still fail as it will definitely ignore disconnected displays:-
> 
> https://github.com/MythTV/mythtv/blob/master/mythtv/libs/libmythui/platforms/mythdisplayx11.cpp#L254
> 
> It's easy enough to add workarounds to the MythTV side (i.e. fallback
> to a disconnected display that has some valid modes) - but not so sure
> about the Qt side; we rely on QScreen being valid.
> 
> I'll have a dig around.
> 
> Regards
> Mark
> 
> On Tue, 27 Oct 2020 at 19:42, Paul Gardiner <lists at glidos.net> wrote:
>>
>> I've recently moved from nvidia to Intel graphics for my frontend. With
>> nvidia, I could specify CustomEDID and ConnectedMonitor options in my
>> xorg.conf so that mythfrontend would start up before the TV was turned
>> on, but Intel graphics doesn't support the ConnectedMonitor option and I
>> so far can't find an alternative.
>>
>> When mythfrontend starts it reports failure to find a screen and
>> attempts to set a mode with 0fps, although xrandr correctly reports the
>> modes specified via CustomEDID.
>>
>> I've tried various alterations to no avail.
>>
>> * Specifying custom edid and an enabled output via KMS, but that seemed
>> to have no effect.
>>
>> * Setting the primary output with xrandr before starting mythfrontend
>>
>> * Specifying monitor definitions in the x config with the Ignore option
>> set to True for all outputs other than HDMI1.
>>
>> Nothing has worked, although the system has fooled me into thinking it
>> is working several times.
>>
>> Hope someone has some more suggestions. Here are various logs:
>>
>>
>>
>> mythfrontend.log: https://pastebin.pl/view/7f7e9805
>>
>>
>>
>> Xorg.0.log: https://pastebin.pl/view/96d06f27
>>
>>
>>
>> xorg.conf:
>>
>> Section "Monitor"
>>       Identifier     "Monitor0"
>>       Option         "Enable" "True"
>> EndSection
>>
>> Section "Device"
>>       Identifier     "Device0"
>>       Driver         "intel"
>>       VendorName     "Intel Corporation"
>>       Option         "CustomEDID" "HDMI1:/etc/X11/edid.bin
>>       Option         "monitor-HDMI1" "Monitor0"
>> EndSection
>>
>>
>>
>> xrandr output:
>>
>> Screen 0: minimum 8 x 8, current 1024 x 768, maximum 32767 x 32767
>> DP1 disconnected primary (normal left inverted right x axis y axis)
>> HDMI1 disconnected (normal left inverted right x axis y axis)
>>      1920x1080     50.00 +  60.00    24.00
>>      1920x1080i    50.00    60.00
>>      1280x1024     60.02
>>      1280x720      50.00    60.00
>>      1440x576i     50.00
>>      1024x768      60.00
>>      1440x480i     59.94
>>      800x600       60.32
>>      720x576       50.00
>>      720x480       59.94
>>      640x480       59.94
>> HDMI2 disconnected (normal left inverted right x axis y axis)
>> VIRTUAL1 disconnected (normal left inverted right x axis y axis)
>> _______________________________________________
>> mythtv-users mailing list
>> mythtv-users at mythtv.org
>> http://lists.mythtv.org/mailman/listinfo/mythtv-users
>> http://wiki.mythtv.org/Mailing_List_etiquette
>> MythTV Forums: https://forum.mythtv.org
> _______________________________________________
> mythtv-users mailing list
> mythtv-users at mythtv.org
> http://lists.mythtv.org/mailman/listinfo/mythtv-users
> http://wiki.mythtv.org/Mailing_List_etiquette
> MythTV Forums: https://forum.mythtv.org
> 


More information about the mythtv-users mailing list