diff mbox

drm/i915: Fix VLV DP RBR/HDMI/DAC PLL LPF coefficients

Message ID 1373041298-15523-1-git-send-email-ville.syrjala@linux.intel.com (mailing list archive)
State New, archived
Headers show

Commit Message

Ville Syrjälä July 5, 2013, 4:21 p.m. UTC
From: Ville Syrjälä <ville.syrjala@linux.intel.com>

I just got confirmation that we're using some old values for the PLL
LPF coefficients for DP RBR/HDMI/DAC on VLV. The
VLV2A0_DP_eDP_HDMI_DPIO_driver_vbios_notes_9 document lists both values
by mistake, and apparently we had picked the wrong one. Change the
coefficients to the recommended values.

Changing the value doesn't appear to destabilize the VGA output picture
even with my sensitive HP ZR24w display. Also HDMI output to my TV still
works fine.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
---
 drivers/gpu/drm/i915/intel_display.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

Jesse Barnes July 9, 2013, 4:21 p.m. UTC | #1
On Fri,  5 Jul 2013 19:21:38 +0300
ville.syrjala@linux.intel.com wrote:

> From: Ville Syrjälä <ville.syrjala@linux.intel.com>
> 
> I just got confirmation that we're using some old values for the PLL
> LPF coefficients for DP RBR/HDMI/DAC on VLV. The
> VLV2A0_DP_eDP_HDMI_DPIO_driver_vbios_notes_9 document lists both values
> by mistake, and apparently we had picked the wrong one. Change the
> coefficients to the recommended values.
> 
> Changing the value doesn't appear to destabilize the VGA output picture
> even with my sensitive HP ZR24w display. Also HDMI output to my TV still
> works fine.
> 
> Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
> ---
>  drivers/gpu/drm/i915/intel_display.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
> index fc2af13..b423432 100644
> --- a/drivers/gpu/drm/i915/intel_display.c
> +++ b/drivers/gpu/drm/i915/intel_display.c
> @@ -4448,7 +4448,7 @@ static void vlv_update_pll(struct intel_crtc *crtc)
>  	    intel_pipe_has_type(&crtc->base, INTEL_OUTPUT_ANALOG) ||
>  	    intel_pipe_has_type(&crtc->base, INTEL_OUTPUT_HDMI))
>  		vlv_dpio_write(dev_priv, DPIO_LPF_COEFF(pipe),
> -				 0x005f0021);
> +				 0x009f0003);
>  	else
>  		vlv_dpio_write(dev_priv, DPIO_LPF_COEFF(pipe),
>  				 0x00d0000f);

Reviewed-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Daniel Vetter July 9, 2013, 8:27 p.m. UTC | #2
On Tue, Jul 09, 2013 at 09:21:41AM -0700, Jesse Barnes wrote:
> On Fri,  5 Jul 2013 19:21:38 +0300
> ville.syrjala@linux.intel.com wrote:
> 
> > From: Ville Syrjälä <ville.syrjala@linux.intel.com>
> > 
> > I just got confirmation that we're using some old values for the PLL
> > LPF coefficients for DP RBR/HDMI/DAC on VLV. The
> > VLV2A0_DP_eDP_HDMI_DPIO_driver_vbios_notes_9 document lists both values
> > by mistake, and apparently we had picked the wrong one. Change the
> > coefficients to the recommended values.
> > 
> > Changing the value doesn't appear to destabilize the VGA output picture
> > even with my sensitive HP ZR24w display. Also HDMI output to my TV still
> > works fine.
> > 
> > Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
> > ---
> >  drivers/gpu/drm/i915/intel_display.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> > 
> > diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
> > index fc2af13..b423432 100644
> > --- a/drivers/gpu/drm/i915/intel_display.c
> > +++ b/drivers/gpu/drm/i915/intel_display.c
> > @@ -4448,7 +4448,7 @@ static void vlv_update_pll(struct intel_crtc *crtc)
> >  	    intel_pipe_has_type(&crtc->base, INTEL_OUTPUT_ANALOG) ||
> >  	    intel_pipe_has_type(&crtc->base, INTEL_OUTPUT_HDMI))
> >  		vlv_dpio_write(dev_priv, DPIO_LPF_COEFF(pipe),
> > -				 0x005f0021);
> > +				 0x009f0003);
> >  	else
> >  		vlv_dpio_write(dev_priv, DPIO_LPF_COEFF(pipe),
> >  				 0x00d0000f);
> 
> Reviewed-by: Jesse Barnes <jbarnes@virtuousgeek.org>

Queued for -next, thanks for the patch.
-Daniel
diff mbox

Patch

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index fc2af13..b423432 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -4448,7 +4448,7 @@  static void vlv_update_pll(struct intel_crtc *crtc)
 	    intel_pipe_has_type(&crtc->base, INTEL_OUTPUT_ANALOG) ||
 	    intel_pipe_has_type(&crtc->base, INTEL_OUTPUT_HDMI))
 		vlv_dpio_write(dev_priv, DPIO_LPF_COEFF(pipe),
-				 0x005f0021);
+				 0x009f0003);
 	else
 		vlv_dpio_write(dev_priv, DPIO_LPF_COEFF(pipe),
 				 0x00d0000f);