Hi Russell, On 01/06/2014 10:46 AM, Russell King - ARM Linux wrote: > On Mon, Jan 06, 2014 at 06:41:28PM +0100, Philipp Zabel wrote: >> Hi Eric, >> >> Am Freitag, den 03.01.2014, 12:14 -0700 schrieb Eric Nelson: >>> This is an issue we've seen before. The SABRE Lite board has >>> a voltage divider on the HPD pins and some monitors (esp. DVI >>> monitors) either don't drive things high enough to assert HPD or >>> bounce with connect/disconnect. >> >> Yes, I used a DVI monitor. >> >>> We've instrumented our 3.0.35 kernels to use the RX_SENSE bits >>> instead. >> >> Reacting to RX_SENSE0 instead of HPD seems to work. > > However, it's non-compliant, because HPD can be lowered and raised by > the sink when it changes its EDID data (eg, because you're connected > through a switch and the routing has been changed.) > > So, reacting to RX_SENSE0 instead of HPD has to be a work-around enabled > only for those boards which are broken in this regard. >
I understand. We'll need to carry some patches for a while though, since there are lots of these boards in the wild. Regards, Eric