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

[Souza, Jose]

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"?
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,