Re: [PATCH] drm/i915: Enable pixel replicated modes on BDW and HSW.

[Daniel Vetter <daniel@ffwll.ch>]

On Wed, Sep 24, 2014 at 11:19:17AM +0300, Jani Nikula wrote:
> On Tue, 23 Sep 2014, clinton.a.taylor@intel.com wrote:
> > From: Clint Taylor <clinton.a.taylor@intel.com>
> >
> > Haswell and later silicon has added a new pixel replication register
> > to the pipe timings for each transcoder. Now in addition to the
> > DPLL_A_MD register for the pixel clock double, we also need to write to
> > the TRANS_MULT_n (0x6002c) register to double the pixel data. Writing
> > to the DPLL only double the pixel clock.
> 
> Any idea of the failure modes that this will fix? I'm wondering if we
> already have bugs for this.

Should only be possible to hit since we've enabled doubleclocked hdmi
modes with

commit 697c4078c765c02b9c4ca2d828ae4d7af62453a6
Author: Clint Taylor <clinton.a.taylor@intel.com>
Date:   Tue Sep 2 17:03:36 2014 -0700

    drm/i915/hdmi: Enable pipe pixel replication for SD interlaced modes

Would be impressive if we'd have a hsw/bdw bug report about this already
;-)

Cheers, Daniel

> 
> BR,
> Jani.
> 
> >
> > Signed-off-by: Clint Taylor <clinton.a.taylor@intel.com>
> > ---
> >  drivers/gpu/drm/i915/i915_reg.h      |    3 +++
> >  drivers/gpu/drm/i915/intel_display.c |    6 +++++-
> >  2 files changed, 8 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
> > index 15c0eaa..7c078d9 100644
> > --- a/drivers/gpu/drm/i915/i915_reg.h
> > +++ b/drivers/gpu/drm/i915/i915_reg.h
> > @@ -2431,6 +2431,7 @@ enum punit_power_well {
> >  #define _PIPEASRC	0x6001c
> >  #define _BCLRPAT_A	0x60020
> >  #define _VSYNCSHIFT_A	0x60028
> > +#define _MULTIPLY_A	0x6002c
> >  
> >  /* Pipe B timing regs */
> >  #define _HTOTAL_B	0x61000
> > @@ -2442,6 +2443,7 @@ enum punit_power_well {
> >  #define _PIPEBSRC	0x6101c
> >  #define _BCLRPAT_B	0x61020
> >  #define _VSYNCSHIFT_B	0x61028
> > +#define _MULTIPLY_B	0x6102c
> >  
> >  #define TRANSCODER_A_OFFSET 0x60000
> >  #define TRANSCODER_B_OFFSET 0x61000
> > @@ -2462,6 +2464,7 @@ enum punit_power_well {
> >  #define BCLRPAT(trans) _TRANSCODER2(trans, _BCLRPAT_A)
> >  #define VSYNCSHIFT(trans) _TRANSCODER2(trans, _VSYNCSHIFT_A)
> >  #define PIPESRC(trans) _TRANSCODER2(trans, _PIPEASRC)
> > +#define MULTIPLY(trans) _TRANSCODER2(trans, _MULTIPLY_A)
> >  
> >  /* HSW+ eDP PSR registers */
> >  #define EDP_PSR_BASE(dev)                       (IS_HASWELL(dev) ? 0x64800 : 0x6f800)
> > diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
> > index c092ff4..e58fcde 100644
> > --- a/drivers/gpu/drm/i915/intel_display.c
> > +++ b/drivers/gpu/drm/i915/intel_display.c
> > @@ -4152,6 +4152,9 @@ static void haswell_crtc_enable(struct drm_crtc *crtc)
> >  
> >  	intel_set_pipe_timings(intel_crtc);
> >  
> > +	I915_WRITE(MULTIPLY(intel_crtc->config.cpu_transcoder),
> > +			    intel_crtc->config.pixel_multiplier - 1);
> > +
> >  	if (intel_crtc->config.has_pch_encoder) {
> >  		intel_cpu_transcoder_set_m_n(intel_crtc,
> >  				     &intel_crtc->config.fdi_m_n, NULL);
> > @@ -7811,7 +7814,8 @@ static bool haswell_get_pipe_config(struct intel_crtc *crtc,
> >  		pipe_config->ips_enabled = hsw_crtc_supports_ips(crtc) &&
> >  			(I915_READ(IPS_CTL) & IPS_ENABLE);
> >  
> > -	pipe_config->pixel_multiplier = 1;
> > +	pipe_config->pixel_multiplier =
> > +			I915_READ(MULTIPLY(pipe_config->cpu_transcoder)) + 1;
> >  
> >  	return true;
> >  }
> > -- 
> > 1.7.9.5
> >
> > _______________________________________________
> > Intel-gfx mailing list
> > Intel-gfx@lists.freedesktop.org
> > http://lists.freedesktop.org/mailman/listinfo/intel-gfx
> 
> -- 
> Jani Nikula, Intel Open Source Technology Center
> _______________________________________________
> Intel-gfx mailing list
> Intel-gfx@lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/intel-gfx

-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch