Re: ✓ Fi.CI.BAT: success for series starting with [1/5] drm/i915: Splitting intel_dp_detect

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

On Wed, 06 Apr 2016, Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com> wrote:
> On 04/04/16 12:41, Tvrtko Ursulin wrote:
>>
>> On 04/04/16 12:08, Jani Nikula wrote:
>>> On Mon, 04 Apr 2016, Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>
>>> wrote:
>>>> On 01/04/16 08:41, Ander Conselvan De Oliveira wrote:
>>>>> On Thu, 2016-03-31 at 12:38 +0000, Patchwork wrote:
>>>>>> == Series Details ==
>>>>>>
>>>>>> Series: series starting with [1/5] drm/i915: Splitting intel_dp_detect
>>>>>> URL   : https://patchwork.freedesktop.org/series/5044/
>>>>>> State : success
>>>>>
>>>>> I pushed those to dinq.
>>>>
>>>> This series seems to break eDP detection on BDW RVP.
>>>
>>> I presume this is due to the sink count check. Can you add debug logging
>>> to print intel_dp->sink_count after it's been read in
>>> intel_dp_get_dpcd() please?
>>
>> intel_dp->sink_count is zero here. (raw value, before the
>> DP_GET_SINK_COUNT.)
>>
>> Also, intel_dp_dpcd_read_wake suggests a possibility for reading garbage
>> with not overly confident wording for the workaround there.
>>
>>> Then the question is, is this just because you have an RVP with who
>>> knows what panel, or do we have to take into account potentially broken
>>> panels too? Then I assume the fix would be to to ignore sink count for
>>> eDP.
>>
>> No idea. :)
>
> I could really use a solution for this. My only development platform is 
> incapacitated unless I revert this series which, apart from the extra 
> work when preparing and sending out patches this is taking, including 
> lost time waiting on CI which I suspect dislikes patches from top of 
> unknown bases, I think it won't be so easy to continue doing so when the 
> conflicts start arriving. :(

Ander, Shubhangi?

Would something like this be sensible? Tvrtko, can you give it a go?

diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index da0c3d29fda8..0890e71db188 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -3799,6 +3799,9 @@ intel_dp_get_dpcd(struct intel_dp *intel_dp)
 	 */
 	intel_dp->sink_count = DP_GET_SINK_COUNT(intel_dp->sink_count);
 
+	if (is_edp(intel_dp))
+		intel_dp->sink_count = max(intel_dp->sink_count, 1);
+
 	/*
 	 * SINK_COUNT == 0 and DOWNSTREAM_PORT_PRESENT == 1 implies that
 	 * a dongle is present but no display. Unless we require to know

BR,
Jani.



-- 
Jani Nikula, Intel Open Source Technology Center
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