Re: [PATCH v3 1/4] drm/i915/psr: Clean-up intel_enable_source_psr1()

Chris Wilson
2017-07-12T10:05:49Z

Quoting Dhinakaran Pandiyan (2017-07-12 09:47:25)
> On Tuesday, July 11, 2017 3:19:53 PM PDT Jim Bride wrote:
> > On SKL+ there is a bit in SRD_CTL that software is not supposed to
> > modify, but we currently clobber that bit when we enable PSR. In
> > order to preserve the value of that bit, go ahead and read SRD_CTL
>
> And which bit is that?

I think we would all be happier with keeping the explicit construction
(and a smaller patch) if we used

val |= I915_READ(EDP_PSR_CTL) & EDP_PSR_CTL_RSVD_MASK;

Better name than reserved most welcome, since reserved often means "do
not set; reserved for past/future use" rather than must not modify but
keep. So EDP_PSR_CTL_KEEP_MASK ?
-Chris