[Intel-gfx] [PATCH] drm/i915: Reset dpll_hw_state when selecting a new pll on hsw

[Maarten Lankhorst]

Op 13-10-15 om 15:58 schreef Daniel Vetter:
> On Tue, Oct 13, 2015 at 03:43:28PM +0200, Maarten Lankhorst wrote:
>> Op 13-10-15 om 15:35 schreef Daniel Vetter:
>>> On Tue, Oct 13, 2015 at 03:18:16PM +0200, Maarten Lankhorst wrote:
>>>> Op 23-09-15 om 17:34 schreef Gabriel Feceoru:
>>>>> Using 2 connectors (DVI and VGA) will cause wrpll to be set for
>>>>> INTEL_OUTPUT_HDMI but never reset if switching to INTEL_OUTPUT_VGA
>>>>>
>>>>> Supresses errors like these:
>>>>> [drm:intel_pipe_config_compare [i915]] *ERROR* mismatch in dpll_hw_state.wrpll
>>>>>
>>>> Looks like a good idea to always zero it.
>>> Except that we still have a bunch of cases where we recompute clock state
>>> but only partially. Can we just move them all up into a common place
>>> please? That would also catch cases where we simply forget to fill this
>>> out at all.
>>>
>>> One case I noticed is edp in skl_ddi_pll_select, but there's probably
>>> more.
>>>
>> Something like below, with all the memsets for dpll_hw_state removed?
> I think this will blow up since we recompute clock state only when
> needs_modeset is true. So needs a bit more intelligence in deciding when
> to clear it I think.
Oops you're right. Maybe intel_modeset_clear_plls because that's where all the clock state belongs?