[Intel-gfx] [PATCH v2 01/16] drm/i915: Keep vblank interrupts enabled while enabling/disabling planes

[Arun Murthy]

On Mon, May 26, 2014 at 7:26 PM, Daniel Vetter <daniel at ffwll.ch> wrote:
> On Thu, May 22, 2014 at 05:48:06PM +0300, ville.syrjala at linux.intel.com wrote:
>> From: Ville Syrjälä <ville.syrjala at linux.intel.com>
>>
>> Because of the upcoming vblank interrupt driven watermark update
>> mechanism we will have use for vblank interrupts during plane
>> enabling/disabling. So don't call drm_vblank_off() until planes
>> are off, and call drm_vblank_on() just before we start to enable
>> the planes.

Since watermark and display control registers are double buffered
both of them get updated on next blank and hence in sync.
Can you let me know the need for vblank driven watermark updates?

Thanks and Regards,
Arun R Murthy
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