[Intel-gfx] [PATCH] drm/i915/vlv: DP_SINK_COUNT is not reliable for valleyview platform.

[Wang, Quanxian]

> -----Original Message-----
> From: Jani Nikula [mailto:jani.nikula at linux.intel.com]
> Sent: Friday, June 13, 2014 5:12 PM
> To: Daniel Vetter; Wang, Quanxian
> Cc: intel-gfx at lists.freedesktop.org
> Subject: Re: [Intel-gfx] [PATCH] drm/i915/vlv: DP_SINK_COUNT is not
> reliable for valleyview platform.
> 
> On Fri, 13 Jun 2014, Daniel Vetter <daniel at ffwll.ch> wrote:
> > On Fri, Jun 13, 2014 at 02:52:04PM +0800, Quanxian Wang wrote:
> >> DP connector will be disconnected after chvt to another console for
> >> 10 minutes or more on valleyview platform VTC1010.
> >
> > This needs _much_ more detail, really.
> >
> > Also it smells like we work around a sink issue, which means the
> > correct quirk is to use some sink id (like OUI), _not_ the platform.
> > Since this way you break all DP1.1+ stuff on vlv and if someone puts
> > this panel onto a different platform it still doesn't work.
> 
> Furthermore you should end up in this code path *only* if you have a DP
> branch device. This shouldn't happen for eDP or native DP displays. Please
> confirm what kind of setup you're experiencing issues with.
> 
> Frankly I wouldn't be surpised if we do have issues with branch devices, but
> this is not the fix.
[Wang, Quanxian] Any idea how to do it? Currently in VTC1010 device, we use native DP to connect HDMI monitor.(DP2HDMI)
This case will happen.
> 
> 
> BR,
> Jani.
> 
> 
> >
> > Or I completely don't understand this at all.
> >
> > Also, such a patch needs a full spec quote or a w/a citation or
> > something solid if it's a more generic issue.
> > -Daniel
> >>
> >> Signed-off-by: Quanxian Wang <quanxian.wang at intel.com>
> >> ---
> >>  drivers/gpu/drm/i915/intel_dp.c | 4 +++-
> >>  1 file changed, 3 insertions(+), 1 deletion(-)
> >>
> >> diff --git a/drivers/gpu/drm/i915/intel_dp.c
> >> b/drivers/gpu/drm/i915/intel_dp.c index 2688f6d..0d127a5 100644
> >> --- a/drivers/gpu/drm/i915/intel_dp.c
> >> +++ b/drivers/gpu/drm/i915/intel_dp.c
> >> @@ -2942,6 +2942,7 @@ intel_dp_check_link_status(struct intel_dp
> >> *intel_dp)  static enum drm_connector_status
> >> intel_dp_detect_dpcd(struct intel_dp *intel_dp)  {
> >> +	struct drm_device *dev = intel_dp_to_dev(intel_dp);
> >>  	uint8_t *dpcd = intel_dp->dpcd;
> >>  	uint8_t type;
> >>
> >> @@ -2953,7 +2954,8 @@ intel_dp_detect_dpcd(struct intel_dp *intel_dp)
> >>  		return connector_status_connected;
> >>
> >>  	/* If we're HPD-aware, SINK_COUNT changes dynamically */
> >> -	if (intel_dp->dpcd[DP_DPCD_REV] >= 0x11 &&
> >> +	if (!IS_VALLEYVIEW(dev) &&
> >> +	    intel_dp->dpcd[DP_DPCD_REV] >= 0x11 &&
> >>  	    intel_dp->downstream_ports[0] & DP_DS_PORT_HPD) {
> >>  		uint8_t reg;
> >>  		if (!intel_dp_aux_native_read_retry(intel_dp,
> DP_SINK_COUNT,
> >> --
> >> 1.8.1.2
> >>
> >> _______________________________________________
> >> Intel-gfx mailing list
> >> Intel-gfx at lists.freedesktop.org
> >> http://lists.freedesktop.org/mailman/listinfo/intel-gfx
> >
> > --
> > Daniel Vetter
> > Software Engineer, Intel Corporation
> > +41 (0) 79 365 57 48 - http://blog.ffwll.ch
> > _______________________________________________
> > Intel-gfx mailing list
> > Intel-gfx at lists.freedesktop.org
> > http://lists.freedesktop.org/mailman/listinfo/intel-gfx
> 
> --
> Jani Nikula, Intel Open Source Technology Center