[Intel-gfx] [PATCH] drm/i915: Limit the auto arming of mmio debugs on vlv/chv

[Daniel Vetter]

On Wed, Jan 20, 2016 at 12:32:23PM +0200, Mika Kuoppala wrote:
> The capability to detect unclaimed register access was
> recently introduced for vlv/chv platforms. Apparently
> there are plenty of unclaimed access on these platforms,
> resulting in new dmesg warns. But as we are trying to form
> a beachhead for CI/Bat, all new warns are adding to the
> noise and thus not desirable at this point in time.
> 
> Make it so that if in these platforms the automatic arming
> was responsible for mmio_debug enabling, ignore the warns.
> 
> If user/dev wants to fix these, he can still do so by
> i915.mmio_debug=1234.
> 
> Cc: Daniel Vetter <daniel.vetter at ffwll.ch>
> Signed-off-by: Mika Kuoppala <mika.kuoppala at intel.com>

Yeah it sucks, but otoh this will make CI more useful for everyone else
and we can keep the original test coverage even.

Reviewed-by: Daniel Vetter <daniel.vetter at ffwll.ch>

> ---
>  drivers/gpu/drm/i915/intel_uncore.c | 9 +++++++++
>  1 file changed, 9 insertions(+)
> 
> diff --git a/drivers/gpu/drm/i915/intel_uncore.c b/drivers/gpu/drm/i915/intel_uncore.c
> index c3c13dc929cb..bfa79e5c214e 100644
> --- a/drivers/gpu/drm/i915/intel_uncore.c
> +++ b/drivers/gpu/drm/i915/intel_uncore.c
> @@ -631,6 +631,15 @@ __unclaimed_reg_debug(struct drm_i915_private *dev_priv,
>  		      const bool read,
>  		      const bool before)
>  {
> +	/* XXX. We limit the auto arming traces for mmio
> +	 * debugs on these platforms. There are just too many
> +	 * revealed by these and CI/Bat suffers from the noise.
> +	 * Please fix and then re-enable the automatic traces.
> +	 */
> +	if (i915.mmio_debug < 2 &&
> +	    (IS_VALLEYVIEW(dev_priv) || IS_CHERRYVIEW(dev_priv)))
> +		return;
> +
>  	if (WARN(check_for_unclaimed_mmio(dev_priv),
>  		 "Unclaimed register detected %s %s register 0x%x\n",
>  		 before ? "before" : "after",
> -- 
> 2.5.0
> 

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