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

[Daniel Vetter]

On Mon, Aug 10, 2015 at 02:01:56PM +0300, Jani Nikula wrote:
> 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... :(

Well I like the idea, Mika please supply a fixup patch.
-Daniel

> 
> 
> >
> > 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
> _______________________________________________
> Intel-gfx mailing list
> Intel-gfx at lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/intel-gfx

-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch