[Intel-gfx] [PATCH 02/23] drm/i915: Tune down WARNs about TBT AUX power well enabling

[Imre Deak]

On Fri, Jun 07, 2019 at 08:50:34PM +0300, Souza, Jose wrote:
> On Tue, 2019-06-04 at 17:58 +0300, Imre Deak wrote:
> > The HW completion flag for the TBT AUX power well enabling/disabling
> > gets stuck if the firmware tears down the TBT DP tunnel before the
> > completion.
> > 
> > We shouldn't complain about the timeout, since it's expected to
> > happen
> > and doesn't cause further issues. We suppress the disabling timeout
> > already, do the same for enabling.
> 
> This was documented in spec?
> 
> > 
> > Cc: José Roberto de Souza <jose.souza at intel.com>
> > Cc: Rodrigo Vivi <rodrigo.vivi at intel.com>
> > Cc: Ville Syrjälä <ville.syrjala at linux.intel.com>
> > Signed-off-by: Imre Deak <imre.deak at intel.com>
> > ---
> >  drivers/gpu/drm/i915/intel_display_power.c | 15 ++++++++++-----
> >  1 file changed, 10 insertions(+), 5 deletions(-)
> > 
> > diff --git a/drivers/gpu/drm/i915/intel_display_power.c
> > b/drivers/gpu/drm/i915/intel_display_power.c
> > index 278a7edc94f5..249a5fa55df6 100644
> > --- a/drivers/gpu/drm/i915/intel_display_power.c
> > +++ b/drivers/gpu/drm/i915/intel_display_power.c
> > @@ -268,11 +268,16 @@ static void
> > hsw_wait_for_power_well_enable(struct drm_i915_private *dev_priv,
> >  	int pw_idx = power_well->desc->hsw.idx;
> >  
> >  	/* Timeout for PW1:10 us, AUX:not specified, other PWs:20 us.
> > */
> > -	WARN_ON(intel_wait_for_register(&dev_priv->uncore,
> > -					regs->driver,
> > -					HSW_PWR_WELL_CTL_STATE(pw_idx),
> > -					HSW_PWR_WELL_CTL_STATE(pw_idx),
> > -					1));
> > +	if (intel_wait_for_register(&dev_priv->uncore,
> > +				    regs->driver,
> > +				    HSW_PWR_WELL_CTL_STATE(pw_idx),
> > +				    HSW_PWR_WELL_CTL_STATE(pw_idx),
> > +				    1)) {
> > +		DRM_DEBUG_KMS("%s forced off\n", power_well->desc-
> > >name);
> 
> Maybe "%s power well enable timeout"?

Yep, makes sense, will change this.

> Anyways we can fix that latter.
> 
> Reviewed-by: José Roberto de Souza <jose.souza at intel.com>
> 
> > +
> > +		/* An AUX timeout is expected if the TBT DP tunnel is
> > down. */
> > +		WARN_ON(!power_well->desc->hsw.is_tc_tbt);
> > +	}
> >  }
> >  
> >  static u32 hsw_power_well_requesters(struct drm_i915_private
> > *dev_priv,