[Intel-gfx] [PATCH v2 1/6] drm/i915: Iterate over pipe and skip the disabled one

[Anshuman Gupta]

On 2020-02-07 at 16:47:53 +0200, Ville Syrjälä wrote:
> On Fri, Feb 07, 2020 at 07:50:37PM +0530, Anshuman Gupta wrote:
> > It should not be assumed that a disabled display pipe will be
> > always last the pipe.
> > for_each_pipe() should iterate over I915_MAX_PIPES and check
> > for the disabled pipe and skip that pipe so that it should not
> > initialize the intel crtc for any disabled pipes.
> > 
> > Below compilation error require to be handle due to change in
> > for_each_pipe() macro.
> > "suggest explicit braces to avoid ambiguous ‘else’ [-Werror=dangling-else]"
> > 
> > Cc: Ville Syrjälä <ville.syrjala at linux.intel.com>
> > Signed-off-by: Anshuman Gupta <anshuman.gupta at intel.com>
> > ---
> >  drivers/gpu/drm/i915/display/intel_display.h | 5 +++--
> >  drivers/gpu/drm/i915/i915_irq.c              | 6 ++++--
> >  2 files changed, 7 insertions(+), 4 deletions(-)
> > 
> > diff --git a/drivers/gpu/drm/i915/display/intel_display.h b/drivers/gpu/drm/i915/display/intel_display.h
> > index 75438a136d58..7a531e485b53 100644
> > --- a/drivers/gpu/drm/i915/display/intel_display.h
> > +++ b/drivers/gpu/drm/i915/display/intel_display.h
> > @@ -313,10 +313,11 @@ enum phy_fia {
> >  };
> >  
> >  #define for_each_pipe(__dev_priv, __p) \
> > -	for ((__p) = 0; (__p) < INTEL_NUM_PIPES(__dev_priv); (__p)++)
> > +	for ((__p) = 0; (__p) < I915_MAX_PIPES; (__p)++) \
> > +		for_each_if((INTEL_INFO(__dev_priv)->pipe_mask) & BIT(__p))
> 
> Don't need the parens around the (->pipe_mask)
Thanks for review i will address this.
> 
> >  
> >  #define for_each_pipe_masked(__dev_priv, __p, __mask) \
> > -	for ((__p) = 0; (__p) < INTEL_NUM_PIPES(__dev_priv); (__p)++) \
> > +	for_each_pipe(__dev_priv, __p) \
> >  		for_each_if((__mask) & BIT(__p))
> 
> Shouldn't this one still consult the pipe_mask? There's no reason to
> assume that the caller bothered to filter the mask it passed in.
AFAIU current caller is interested to init the pipe {IIR,IMR,IER}
for the passed mask. Please correct me if i am wrong
here. 
Thanks,
Anshuman Gupta.
> 
> >  
> >  #define for_each_cpu_transcoder_masked(__dev_priv, __t, __mask) \
> > diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
> > index 3d0cd0960bd2..a26f2bf1b6ea 100644
> > --- a/drivers/gpu/drm/i915/i915_irq.c
> > +++ b/drivers/gpu/drm/i915/i915_irq.c
> > @@ -1739,11 +1739,12 @@ static void ibx_irq_handler(struct drm_i915_private *dev_priv, u32 pch_iir)
> >  	if (pch_iir & SDE_POISON)
> >  		drm_err(&dev_priv->drm, "PCH poison interrupt\n");
> >  
> > -	if (pch_iir & SDE_FDI_MASK)
> > +	if (pch_iir & SDE_FDI_MASK) {
> >  		for_each_pipe(dev_priv, pipe)
> >  			drm_dbg(&dev_priv->drm, "  pipe %c FDI IIR: 0x%08x\n",
> >  				pipe_name(pipe),
> >  				I915_READ(FDI_RX_IIR(pipe)));
> > +	}
> >  
> >  	if (pch_iir & (SDE_TRANSB_CRC_DONE | SDE_TRANSA_CRC_DONE))
> >  		drm_dbg(&dev_priv->drm, "PCH transcoder CRC done interrupt\n");
> > @@ -1823,11 +1824,12 @@ static void cpt_irq_handler(struct drm_i915_private *dev_priv, u32 pch_iir)
> >  	if (pch_iir & SDE_AUDIO_CP_CHG_CPT)
> >  		drm_dbg(&dev_priv->drm, "Audio CP change interrupt\n");
> >  
> > -	if (pch_iir & SDE_FDI_MASK_CPT)
> > +	if (pch_iir & SDE_FDI_MASK_CPT) {
> >  		for_each_pipe(dev_priv, pipe)
> >  			drm_dbg(&dev_priv->drm, "  pipe %c FDI IIR: 0x%08x\n",
> >  				pipe_name(pipe),
> >  				I915_READ(FDI_RX_IIR(pipe)));
> > +	}
> >  
> >  	if (pch_iir & SDE_ERROR_CPT)
> >  		cpt_serr_int_handler(dev_priv);
> > -- 
> > 2.24.0
> 
> -- 
> Ville Syrjälä
> Intel