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

[Jani Nikula <jani.nikula@linux.intel.com>]

On Mon, 16 Jun 2014, "Wang, Quanxian" <quanxian.wang@intel.com> wrote:
>> -----Original Message-----
>> From: Jani Nikula [mailto:jani.nikula@linux.intel.com]
>> Sent: Friday, June 13, 2014 5:12 PM
>> To: Daniel Vetter; Wang, Quanxian
>> Cc: intel-gfx@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@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.

So it's an active adapter?

Please send full dmesg from early booth with drm.debug=0xe module
parameter set, exhibiting the problem.

BR,
Jani.








>> 
>> 
>> 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@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@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@lists.freedesktop.org
>> > http://lists.freedesktop.org/mailman/listinfo/intel-gfx
>> 
>> --
>> Jani Nikula, Intel Open Source Technology Center

-- 
Jani Nikula, Intel Open Source Technology Center