[PATCH RFC 27/46] imx-drm: convert to componentised device support

[Russell King - ARM Linux]

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.

-- 
FTTC broadband for 0.8mile line: 5.8Mbps down 500kbps up.  Estimation
in database were 13.1 to 19Mbit for a good line, about 7.5+ for a bad.
Estimate before purchase was "up to 13.2Mbit".