[Intel-gfx] [PATCH] drm/i915: Spam less on dp aux send/receive problems

[Jani Nikula]

On Mon, 10 Aug 2015, Jani Nikula <jani.nikula at linux.intel.com> wrote:
> On Thu, 06 Aug 2015, Mika Kuoppala <mika.kuoppala at linux.intel.com> wrote:
>> If we encounter frequent problems with dp aux channel
>> communications, we end up spamming the dmesg with the
>> exact similar trace and status.
>>
>> Inject a new backtrace only if we have new information
>> to share as otherwise we flush out all other important
>> stuff.
>>
>> Signed-off-by: Mika Kuoppala <mika.kuoppala at intel.com>
>> ---
>>  drivers/gpu/drm/i915/intel_dp.c | 11 +++++++++--
>>  1 file changed, 9 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
>> index df7e2cf..6b2f7af 100644
>> --- a/drivers/gpu/drm/i915/intel_dp.c
>> +++ b/drivers/gpu/drm/i915/intel_dp.c
>> @@ -849,8 +849,15 @@ intel_dp_aux_ch(struct intel_dp *intel_dp,
>>  	}
>>  
>>  	if (try == 3) {
>> -		WARN(1, "dp_aux_ch not started status 0x%08x\n",
>> -		     I915_READ(ch_ctl));
>> +		static u32 last_status = -1;
>> +		const u32 status = I915_READ(ch_ctl);
>> +
>> +		if (status != last_status) {
>> +			WARN(1, "dp_aux_ch not started status 0x%08x\n",
>> +			     status);
>> +			last_status = status;
>> +		}
>> +
>
> But now you'll also skip the logging even if there's been a day and a
> million successful transfers since the last error... I understand your
> concern, but if you feel you must do something like this, please at
> least reset last_status on success.

Hmh, I see now that this has already been merged... :(


>
> BR,
> Jani.
>
>
>>  		ret = -EBUSY;
>>  		goto out;
>>  	}
>> -- 
>> 2.1.4
>>
>> _______________________________________________
>> 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

-- 
Jani Nikula, Intel Open Source Technology Center