[Intel-gfx] [PATCH] drm/i915/skl: Tune down DC6 already enabled warning

[Daniel Vetter]

On Mon, Jan 18, 2016 at 05:08:42PM +0100, Patrik Jakobsson wrote:
> For unknown reasons the DMC firmware overwrites our DC5/6 bits in
> the DC_STATE_EN register. This happens from time to time during the
> igt at kms_flip@basic-flip-vs-dpms test. We manually fix up the register
> when this occurs and so far that seems to work. This patch demotes the
> warning to a debug message to not clutter our CI results.
> 
> Bug: https://bugs.freedesktop.org/show_bug.cgi?id=93697

Bugzilla: is what we generally use here.

> Cc: Daniel Vetter <daniel.vetter at ffwll.ch>
> Signed-off-by: Patrik Jakobsson <patrik.jakobsson at linux.intel.com>

Reviewed-by: Daniel Vetter <daniel.vetter at ffwll.ch> since it tunes down CI
noise. Unfortunately we have indication that it relates to skl hard hangs,
so good to keep it at debug level for sure.
-Daniel

> ---
>  drivers/gpu/drm/i915/intel_runtime_pm.c | 6 ++++--
>  1 file changed, 4 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/intel_runtime_pm.c b/drivers/gpu/drm/i915/intel_runtime_pm.c
> index 89a7dd8..68e213c 100644
> --- a/drivers/gpu/drm/i915/intel_runtime_pm.c
> +++ b/drivers/gpu/drm/i915/intel_runtime_pm.c
> @@ -574,8 +574,10 @@ static void assert_can_enable_dc6(struct drm_i915_private *dev_priv)
>  	WARN_ONCE(!HAS_RUNTIME_PM(dev), "Runtime PM not enabled.\n");
>  	WARN_ONCE(I915_READ(UTIL_PIN_CTL) & UTIL_PIN_ENABLE,
>  		  "Backlight is not disabled.\n");
> -	WARN_ONCE((I915_READ(DC_STATE_EN) & DC_STATE_EN_UPTO_DC6),
> -		  "DC6 already programmed to be enabled.\n");
> +
> +	/* Sometimes fw incorrectly modify our bits so just debug print this */
> +	if ((I915_READ(DC_STATE_EN) & DC_STATE_EN_UPTO_DC6))
> +		  DRM_DEBUG_KMS("DC6 already programmed to be enabled.\n");
>  
>  	assert_csr_loaded(dev_priv);
>  }
> -- 
> 2.5.0
> 

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