Re: [PATCH 01/10] drm/i915: rewrite the LCPLL code

Lespiau, Damien
2012-10-10T12:47:34Z

On Fri, Oct 5, 2012 at 4:05 PM, Paulo Zanoni <przanoni@gmail.com> wrote:

> +static int intel_ddi_get_cdclk_freq(struct drm_i915_private *dev_priv)
> +{
> + if (I915_READ(HSW_FUSE_STRAP) & HSW_CDCLK_LIMIT)
> + return 450;

I don't think reading this fused register is necessary here, it only
really matters when you try to set the LCPLL alternate frequency to
check if the hardware supports it. I'd just rely on the frequency set
bits in LCPLL (if you remove this, it means that the hunk adding the
register definition is not needed any more).

If you really want to check for consistency, then you could warn if
the LCPLL freq has been programmed with 0x1 and HSW_CDCLK_LIMIT is set
(in which case the setting will be ignored). But then, there's nothing
we can do anyway, so well...

--
Damien