[Intel-gfx] [PATCH] drm/i915: Fix VLV PLL LPF coefficients for DAC

[Jesse Barnes]

On Thu, 13 Jun 2013 18:37:35 +0300
ville.syrjala at linux.intel.com wrote:

> From: Ville Syrjälä <ville.syrjala at linux.intel.com>
> 
> The current PLL settings produce a rather unstable picture when
> I hook up a VLV to my HP ZR24w display via a VGA cable.
> 
> According to some docs, we should use the the same LPF coefficients
> for DAC as we do for HDMI and RBR DP. And indeed that seems to cure
> the shivers.
> 
> Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
> ---
> With this the hybrid PLL mode patch can be dropped.
> 
>  drivers/gpu/drm/i915/intel_display.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
> index 29f2c0d..465d6bc 100644
> --- a/drivers/gpu/drm/i915/intel_display.c
> +++ b/drivers/gpu/drm/i915/intel_display.c
> @@ -4405,6 +4405,7 @@ static void vlv_update_pll(struct intel_crtc *crtc)
>  
>  	/* Set HBR and RBR LPF coefficients */
>  	if (crtc->config.port_clock == 162000 ||
> +	    intel_pipe_has_type(&crtc->base, INTEL_OUTPUT_ANALOG) ||
>  	    intel_pipe_has_type(&crtc->base, INTEL_OUTPUT_HDMI))
>  		vlv_dpio_write(dev_priv, DPIO_LFP_COEFF(pipe),
>  				 0x005f0021);

I think it's ok, but can you specify the doc title in the commit
message?  Should make things easier to find in the rat's nest of files
later. :)

-- 
Jesse Barnes, Intel Open Source Technology Center