On Fri, 24 Jan 2020, Anshuman Gupta <anshuman.gupta@xxxxxxxxx> wrote:
> On 2020-01-24 at 14:15:30 +0200, Jani Nikula wrote:
>> On Fri, 24 Jan 2020, Anshuman Gupta <anshuman.gupta@xxxxxxxxx> wrote:
>> > On 2020-01-23 at 15:48:05 +0200, Jani Nikula wrote:
>> >> On Thu, 23 Jan 2020, Anshuman Gupta <anshuman.gupta@xxxxxxxxx> 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.
>> >> >
>> >> > Few compilation error needed to handle accordingly due to
>> >> > change in for_each_pipe() macro.
>> >>
>> >> Really? Please paste.
>> > It is dangling-else warning at couple of places.
>> > drivers/gpu/drm/i915/i915_irq.c:1861:5: error: suggest explicit braces to avoid ambiguous ‘else’ [-Werror=dangling-else]
>> > 1861 | if (pch_iir & SDE_FDI_MASK)
>> > drivers/gpu/drm/i915/i915_irq.c:1944:5: error: suggest explicit braces to avoid ambiguous ‘else’ [-Werror=dangling-else]
>> > 1944 | if (pch_iir & SDE_FDI_MASK_CPT)
>>
>> Right, I suppose this is caused by the nesting of the for loops with
>> if-else.
>>
>> Perhaps the right course of action is to *not* reuse for_each_pipe() in
>> for_each_pipe_masked(). Just combine the conditions into one.
> This is not caused by for_each_pipe_masked, this is caused by for_each_pipe itself,
> if (foo)
> /*for_each_pipe()*/
> for(;;)
> if (condition) {}
> else
Sorry for the noise, please carry on with the patch.
*blush*
BR,
Jani.
>>
>> BR,
>> Jani.
>>
>>
>>
>> >>
>> >> >
>> >> > Cc: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>
>> >> > Signed-off-by: Anshuman Gupta <anshuman.gupta@xxxxxxxxx>
>> >> > ---
>> >> > 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 028aab728514..47813a50add4 100644
>> >> > --- a/drivers/gpu/drm/i915/display/intel_display.h
>> >> > +++ b/drivers/gpu/drm/i915/display/intel_display.h
>> >> > @@ -312,10 +312,11 @@ 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)++) \
>> >>
>> >> Originally I was envisioning using for_each_set_bit() from bitops.h for
>> >> this. It's probably more efficient, however I'm not sure if efficiency
>> >> matters much here. The ugly part is that for_each_set_bit() requires an
>> >> explicit cast to unsigned long *.
>> >>
>> >> Perhaps this is just as well, it's not wrong, and can always be updated
>> >> later.
>> >>
>> >> > + for_each_if((INTEL_INFO(__dev_priv)->pipe_mask) & BIT(__p))
>> >> >
>> >> > #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))
>> >> >
>> >> > #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 94cb25ac504d..22ecd5bc407e 100644
>> >> > --- a/drivers/gpu/drm/i915/i915_irq.c
>> >> > +++ b/drivers/gpu/drm/i915/i915_irq.c
>> >> > @@ -1735,11 +1735,12 @@ static void ibx_irq_handler(struct drm_i915_private *dev_priv, u32 pch_iir)
>> >> > if (pch_iir & SDE_POISON)
>> >> > DRM_ERROR("PCH poison interrupt\n");
>> >> >
>> >> > - if (pch_iir & SDE_FDI_MASK)
>> >> > + if (pch_iir & SDE_FDI_MASK) {
>> >> > for_each_pipe(dev_priv, pipe)
>> >> > DRM_DEBUG_DRIVER(" pipe %c FDI IIR: 0x%08x\n",
>> >> > pipe_name(pipe),
>> >> > I915_READ(FDI_RX_IIR(pipe)));
>> >> > + }
>> >>
>> >> Are the brace changes really needed? This is what the for_each_if hack
>> >> is supposed to tackle.
>> > IMHO it was dangling-else compilation, warning that requires braces.
>> > please correct me if i am wrong.
>> > Thanks,
>> > Anshuman
>> >>
>> >> >
>> >> > if (pch_iir & (SDE_TRANSB_CRC_DONE | SDE_TRANSA_CRC_DONE))
>> >> > DRM_DEBUG_DRIVER("PCH transcoder CRC done interrupt\n");
>> >> > @@ -1818,11 +1819,12 @@ static void cpt_irq_handler(struct drm_i915_private *dev_priv, u32 pch_iir)
>> >> > if (pch_iir & SDE_AUDIO_CP_CHG_CPT)
>> >> > DRM_DEBUG_DRIVER("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_DEBUG_DRIVER(" 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);
>> >>
>> >> --
>> >> Jani Nikula, Intel Open Source Graphics Center
>>
>> --
>> Jani Nikula, Intel Open Source Graphics Center
--
Jani Nikula, Intel Open Source Graphics Center
_______________________________________________
Intel-gfx mailing list
Intel-gfx@xxxxxxxxxxxxxxxxxxxxx
https://lists.freedesktop.org/mailman/listinfo/intel-gfx
