Re: [PATCH v2] drm/i915: Increase LSPCON timeout

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

On Mon, 20 Aug 2018, "Sharma, Shashank" <shashank.sharma@intel.com> wrote:
> On 8/18/2018 1:37 AM, Fredrik Schön wrote:
>
>> 100 ms is not enough time for the LSPCON adapter on Intel NUC devices to
>> settle. This causes dropped display modes at boot or screen reconfiguration.
>> Empirical testing can reproduce the error up to a timeout of 190 ms. Basic
>> boot and stress testing at 200 ms has not (yet) failed.
>>
>> Increase timeout to 400 ms to get some margin of error.
>>
>> Changes from v1:
>> The initial suggestion of 1000 ms was lowered due to concerns about delaying
>> valid timeout cases.
>> Update patch metadata.
>>
>> Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=107503
>> Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1570392
>> Fixes: 357c0ae9198a ("drm/i915/lspcon: Wait for expected LSPCON mode to settle")
>> Cc: Shashank Sharma <shashank.sharma@intel.com>
>> Cc: Imre Deak <imre.deak@intel.com>
>> Cc: Jani Nikula <jani.nikula@intel.com>
>> Cc: <stable@vger.kernel.org> # v4.11+
>> Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
>> Signed-off-by: Fredrik Schön <fredrik.schon@gmail.com>
>> ---
>>   drivers/gpu/drm/i915/intel_lspcon.c | 2 +-
>>   1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/drivers/gpu/drm/i915/intel_lspcon.c b/drivers/gpu/drm/i915/intel_lspcon.c
>> index 8ae8f42f430a..6b6758419fb3 100644
>> --- a/drivers/gpu/drm/i915/intel_lspcon.c
>> +++ b/drivers/gpu/drm/i915/intel_lspcon.c
>> @@ -74,7 +74,7 @@ static enum drm_lspcon_mode lspcon_wait_mode(struct intel_lspcon *lspcon,
>>   	DRM_DEBUG_KMS("Waiting for LSPCON mode %s to settle\n",
>>   		      lspcon_mode_name(mode));
>>   
>> -	wait_for((current_mode = lspcon_get_current_mode(lspcon)) == mode, 100);
>> +	wait_for((current_mode = lspcon_get_current_mode(lspcon)) == mode, 400);
>>   	if (current_mode != mode)
>>   		DRM_ERROR("LSPCON mode hasn't settled\n");
>>   
> Looks good to me
> Reviewed-by: Shashank Sharma <shashank.sharma@intel.com>

Pushed to drm-intel-next-queued, thanks for the patch and review.

BR,
Jani.

-- 
Jani Nikula, Intel Open Source Graphics Center