Re: [Intel-gfx] [PATCH 4/7] drm/i915: Let panel power sequencing hardware do its job

Jesse Barnes
2011-11-02T16:23:17Z

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On Wed, 02 Nov 2011 00:31:40 -0700
Keith Packard <keithp@keithp.com> wrote:

> On Tue, 1 Nov 2011 23:20:27 -0700, Keith Packard <keithp@keithp.com> wrote:
>
> > -static void ironlake_wait_panel_off(struct intel_dp *intel_dp)
> > +#define IDLE_ON_MASK (PP_ON | PP_READY | PP_SEQUENCE_MASK | 0 | PP_SEQUENCE_STATE_MASK)
> > +#define IDLE_ON_VALUE (PP_ON | PP_READY | PP_SEQUENCE_NONE | 0 | PP_SEQUENCE_STATE_ON_IDLE)
>
> A bit more testing -- looks like the MacBook Air doesn't mange to get
> PP_READY set when it's time to turn the panel on. I should look at this
> a bit more closely; there's no reason it shouldn't be set. But, nothing
> bad seems to happen if we simply ignore the PP_READY bit
>
> +#define IDLE_ON_MASK (PP_ON | 0 | PP_SEQUENCE_MASK | 0 | PP_SEQUENCE_STATE_MASK)
> +#define IDLE_ON_VALUE (PP_ON | 0 | PP_SEQUENCE_NONE | 0 | PP_SEQUENCE_STATE_ON_IDLE)

Note that PP_READY will incorrectly depend on some other register
values, so in some configs the panel will happily power up even if
PP_READY isn't set yet...

--
Jesse Barnes, Intel Open Source Technology Center

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