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<b><a class="bz_bug_link
bz_status_NEW "
title="NEW - [GLK] no signal after switch resolution from 1080p@23.98"
href="https://bugs.freedesktop.org/show_bug.cgi?id=105887#c52">Comment # 52</a>
on <a class="bz_bug_link
bz_status_NEW "
title="NEW - [GLK] no signal after switch resolution from 1080p@23.98"
href="https://bugs.freedesktop.org/show_bug.cgi?id=105887">bug 105887</a>
from <span class="vcard"><a class="email" href="mailto:stefano.ruzzon@icloud.com" title="fatez <stefano.ruzzon@icloud.com>"> <span class="fn">fatez</span></a>
</span></b>
<pre>(In reply to Daniel Scheller from <a href="show_bug.cgi?id=105887#c51">comment #51</a>)
<span class="quote">> (In reply to Clinton Taylor from <a href="show_bug.cgi?id=105887#c49">comment #49</a>)
>
> > Issue does not occur if I disable 12 bpc support in the driver.
> >
> > For a quick test:
> >
> > In intel_hdmi.c mothod hdmi_12bpc_possible()
> >
> > add
> > return false;
>
> Using an ASRock J5005-ITX on stock Ubuntu 18.04 w/Kernel 4.15, connected to
> an Onkyo TX-NR509 AV receiver, which shows similar sympthoms (ie. if the
> resolution goes up (pixel clock rate increases) from the boot res to 1080p50
> or 1080p60, the TV picture goes away/blue and the receiver says "No signal".
> The receiver must be power-cycled to get a picture again).
>
> Tried the above (modified Ubuntu kernel sources accordingly, repackaged,
> installed and booted) - makes the issue go away with this workaround,
> switching from 50p/60p to 24p and back works, no "No signal". Everything
> else video-related remains working normally.</span >
Could you explain exactly how to do it? Also I use Ubuntu 18.04</pre>
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