[Intel-gfx] [PATCH] drm/i915/guc: Reduce verbosity on log overflows

[Michal Wajdeczko]

On Tue, 18 Jun 2019 12:24:30 +0200, Chris Wilson  
<chris at chris-wilson.co.uk> wrote:

> Quoting Michal Wajdeczko (2019-06-17 15:38:53)
>> On Mon, 17 Jun 2019 12:09:17 +0200, Chris Wilson
>> <chris at chris-wilson.co.uk> wrote:
>>
>> > If the user is clearing the log buffer too slowly, we overflow. As  
>> this
>> > is an expected condition, and the driver tries to handle it, reduce  
>> the
>> > error message down to a notice.
>> >
>> > Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=110817
>> > Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
>> > Cc: Michal Wajdeczko <michal.wajdeczko at intel.com>
>> > Cc: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
>> > ---
>> >  drivers/gpu/drm/i915/intel_guc_log.c | 4 +++-
>> >  1 file changed, 3 insertions(+), 1 deletion(-)
>> >
>> > diff --git a/drivers/gpu/drm/i915/intel_guc_log.c
>> > b/drivers/gpu/drm/i915/intel_guc_log.c
>> > index bf1446629703..e3b83ecb90b5 100644
>> > --- a/drivers/gpu/drm/i915/intel_guc_log.c
>> > +++ b/drivers/gpu/drm/i915/intel_guc_log.c
>> > @@ -208,7 +208,9 @@ static bool guc_check_log_buf_overflow(struct
>> > intel_guc_log *log,
>> >                       /* buffer_full_cnt is a 4 bit counter */
>> >                       log->stats[type].sampled_overflow += 16;
>> >               }
>> > -             DRM_ERROR_RATELIMITED("GuC log buffer overflow\n");
>> > +
>> > +              
>> dev_notice_ratelimited(guc_to_i915(log_to_guc(log))->drm.dev,
>> > +                                    "GuC log buffer overflow\n");
>>
>> While this change alone is not harmful, I'm afraid that there might
>> be another reason why we see this message : once buffer_full_cnt is
>> turned on by the fw and then we reset the Guc, this field may have
>> stale value as it is not cleared by us/uc and we may wrongly assume
>> that there was an overflow.
>
> So yay/nay on silencing the test output so I can blissfully ignore it in
> bugzilla?

OK to merge, we can debug extra 'notice' logs separately

Michal