[Intel-gfx] [PATCH] drm/i915: set minimum CD clock to twice the BCLK.

[Dhinakaran Pandiyan]

On Wednesday, October 25, 2017 3:02:12 PM PDT abhay.kumar at intel.com wrote:
> From: Abhay Kumar <abhay.kumar at intel.com>
> 
> In glk when device boots with only 1366x768 panel, HDA codec doesn't comeup.
> This result in no audio forever as cdclk is < 96Mhz.
> This chagne will ensure CD clock to be twice of  BCLK.
> 
> Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=102937
> Signed-off-by: Abhay Kumar <abhay.kumar at intel.com>
> ---
>  drivers/gpu/drm/i915/intel_cdclk.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/i915/intel_cdclk.c
> b/drivers/gpu/drm/i915/intel_cdclk.c index e8884c2ade98..185a70f0921c
> 100644
> --- a/drivers/gpu/drm/i915/intel_cdclk.c
> +++ b/drivers/gpu/drm/i915/intel_cdclk.c
> @@ -1920,7 +1920,7 @@ int intel_crtc_compute_min_cdclk(const struct
> intel_crtc_state *crtc_state) /* According to BSpec, "The CD clock
> frequency must be at least twice * the frequency of the Azalia BCLK." and
> BCLK is 96 MHz by default. */
> -	if (crtc_state->has_audio && INTEL_GEN(dev_priv) >= 9)
> +	if (INTEL_GEN(dev_priv) >= 9)

Why should cdclk be increased when audio is not being enabled?

>  		min_cdclk = max(2 * 96000, min_cdclk);
> 
>  	if (min_cdclk > dev_priv->max_cdclk_freq) {