On Thu, Dec 28, 2017 at 08:32:05PM +0530, Sharma, Shashank wrote: > > > On 12/22/2017 11:58 PM, Ville Syrjala wrote: > > From: Ville Syrjälä <ville.syrj...@linux.intel.com> > > > > The LG 4k TV I have doesn't deassert HPD when I turn the TV off, but > > when I turn it back on it will pulse the HPD line. By that time it has > > forgotten everything we told it about scrambling and the clock ratio. > > Hence if we want to get a picture out if it again we have to tell it > > whether we're currently sending scrambled data or not. Implement > > that via the encoder->post_hotplug() hook. > I am not sure if I understood the problem statement correctly. Even if > the TV triggers HPD line while turning it back, I would expect: > - EDID read for TV's detection, which will refresh SCDC and scrambling > capabilities > - A new modeset will be triggered, which will program the scrambling and > high tmds clock ratio again > - Once HDMI controller is programmed, it will generate scrambled signals > till next modeset / disable. > > So why do we need to do this ? I might be missing something, but lets > discus about it.
The EDID is readable even when the HPD gets deasserted for a short perios, hence we never consider the sink as being disconnected. Hence there will be no modeset triggered by userspace. -- Ville Syrjälä Intel OTC _______________________________________________ Intel-gfx mailing list Intel-gfx@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/intel-gfx
