[Intel-gfx] [PATCH v2 5/8] drm/i915: Check error return when converting pipe to connector

[Imre Deak]

On Thu, Apr 27, 2017 at 10:09:35AM +0300, Jani Nikula wrote:
> On Wed, 26 Apr 2017, Imre Deak <imre.deak at intel.com> wrote:
> > An error from intel_get_pipe_from_connector() would mean a bug somewhere
> > else, but we still should check for it to prevent some other more
> > obscure bug later.
> >
> > v2:
> > - Fall back to a reasonable default instead of bailing out in case of
> >   error. (Jani)
> >
> > Cc: Jani Nikula <jani.nikula at intel.com>
> > Signed-off-by: Imre Deak <imre.deak at intel.com>
> > ---
> >  drivers/gpu/drm/i915/intel_panel.c | 17 ++++++++++++++---
> >  1 file changed, 14 insertions(+), 3 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/i915/intel_panel.c b/drivers/gpu/drm/i915/intel_panel.c
> > index cb50c52..3508f42 100644
> > --- a/drivers/gpu/drm/i915/intel_panel.c
> > +++ b/drivers/gpu/drm/i915/intel_panel.c
> > @@ -888,10 +888,14 @@ static void pch_enable_backlight(struct intel_connector *connector)
> >  	struct drm_i915_private *dev_priv = to_i915(connector->base.dev);
> >  	struct intel_panel *panel = &connector->panel;
> >  	enum pipe pipe = intel_get_pipe_from_connector(connector);
> > -	enum transcoder cpu_transcoder =
> > -		intel_pipe_to_cpu_transcoder(dev_priv, pipe);
> > +	enum transcoder cpu_transcoder;
> >  	u32 cpu_ctl2, pch_ctl1, pch_ctl2;
> >  
> > +	if (!WARN_ON_ONCE(pipe == INVALID_PIPE))
> > +		cpu_transcoder = intel_pipe_to_cpu_transcoder(dev_priv, pipe);
> > +	else
> > +		cpu_transcoder = TRANSCODER_EDP;
> > +
> >  	cpu_ctl2 = I915_READ(BLC_PWM_CPU_CTL2);
> >  	if (cpu_ctl2 & BLM_PWM_ENABLE) {
> >  		DRM_DEBUG_KMS("cpu backlight already enabled\n");
> > @@ -973,6 +977,9 @@ static void i965_enable_backlight(struct intel_connector *connector)
> >  	enum pipe pipe = intel_get_pipe_from_connector(connector);
> >  	u32 ctl, ctl2, freq;
> >  
> > +	if (WARN_ON_ONCE(pipe == INVALID_PIPE))
> > +		pipe = PIPE_A;
> > +
> >  	ctl2 = I915_READ(BLC_PWM_CTL2);
> >  	if (ctl2 & BLM_PWM_ENABLE) {
> >  		DRM_DEBUG_KMS("backlight already enabled\n");
> > @@ -1037,6 +1044,9 @@ static void bxt_enable_backlight(struct intel_connector *connector)
> >  	enum pipe pipe = intel_get_pipe_from_connector(connector);
> >  	u32 pwm_ctl, val;
> >  
> > +	if (WARN_ON_ONCE(pipe) == PIPE_INVALID)
> 
> Le pipe invalid? I think you mean INVALID_PIPE here.

Arg, forgot git add at some point..

--Imre

> 
> BR,
> Jani.
> 
> > +		pipe = PIPE_A;
> > +
> >  	/* Controller 1 uses the utility pin. */
> >  	if (panel->backlight.controller == 1) {
> >  		val = I915_READ(UTIL_PIN_CTL);
> > @@ -1093,7 +1103,8 @@ void intel_panel_enable_backlight(struct intel_connector *connector)
> >  	if (!panel->backlight.present)
> >  		return;
> >  
> > -	DRM_DEBUG_KMS("pipe %c\n", pipe_name(pipe));
> > +	if (!WARN_ON_ONCE(pipe == INVALID_PIPE))
> > +		DRM_DEBUG_KMS("pipe %c\n", pipe_name(pipe));
> >  
> >  	mutex_lock(&dev_priv->backlight_lock);
> 
> -- 
> Jani Nikula, Intel Open Source Technology Center