PL111 regression in v4.19-rc1

[Linus Walleij]

On Mon, Aug 27, 2018 at 2:21 PM Noralf Trønnes <noralf at tronnes.org> wrote:

> This is one suspect: 894a677f4b3e
> drm/cma-helper: Use the generic fbdev emulation

This doesn't revert cleanly so I couldn't try that right off.

But the graphics do work before this commit.

I checked out the kernel tree on this commit and it just fails
to create the framebuffer with no messages whatsoever:

versatile-tft-panel 10000000.sysreg:display at 0: no panel detected
drm-clcd-pl111 dev:20: set up callbacks for Versatile PL110
drm-clcd-pl111 dev:20: found bridge on endpoint 1
drm-clcd-pl111 dev:20: Using non-panel bridge
[drm] Supports vblank timestamp caching Rev 2 (21.10.2013).
[drm] No driver support for vblank timestamp query.
[drm] Initialized pl111 1.0.0 20170317 for dev:20 on minor 0

I guess this somehow broke it, then some more stuff down
the road made the damage more visible.

I'm trying to see if I can fix it, any hints welcome!

Yours,
Linus Walleij