[PATCH 0/3] Add CRTC helper drm_crtc_from_index()

[Shawn Guo]

On Fri, Dec 30, 2016 at 12:16:43PM +0100, Daniel Vetter wrote:
> Entire series applied. I suspect that there's more drivers open-coding
> something like this in their vblank code, might be worth it to grep for
> them all and do a quick audit.

I did a round of audit on all drivers vblank code, and found there are
basically 3 categories:

1. Drivers that only support one CRTC.  In this case, the 'pipe' is not
used at all in vblank code.  So we need to do thing about them.
Examples: arm, atmel-hlcdc, mxsfb, etc.

2. Drivers that maintain CRTC pointers and number in the private
structure.  And the fields are used in somewhere else beside vblank
code.  The cleanup will need a bit surgery on the driver code.  I would
leave them out for driver owners/maintainers.  Examples: armada, msm,
sti, etc.

3. Drivers that can use the helper for benefit, including exynos, kirin,
mediatek, nouveau, tegra and vc4.  I have already prepared a series for
these drivers, and will send it out for review shortly.

Shawn