Re: [BISECTED, REGRESSION] v4.12-rc: omapdrm fails to probe on Nokia N900

[Aaro Koskinen]

Hi,

On Fri, Jun 30, 2017 at 09:41:35AM +0300, Tomi Valkeinen wrote:
> On 29/06/17 21:50, Aaro Koskinen wrote:
> > On Thu, Jun 15, 2017 at 09:51:06AM +0300, Tomi Valkeinen wrote:
> >> On 15/06/17 01:11, Aaro Koskinen wrote:
> >>> When booting v4.12-rc5 on Nokia N900, omapdrm fails to probe and there
> >>> is no display.
> >>
> >> Are you sure it doesn't probe? It fails the omapdss_stack_is_ready()
> >> check?
> > 
> > It appears the reason was that I didn't have
> > CONFIG_DRM_OMAP_CONNECTOR_ANALOG_TV enabled.
> > 
> > I think that's wrong. I don't own an analog TV, so why should I enable
> > such option to get device's built-in display working?
> 
> Indeed. Unfortunately I don't have a solution for that.
> 
> DRM doesn't support adding devices after probe. So at omapdrm probe time
> we have to decide which displays to use. In the dts file, n900 defines
> the lcd and analog tv. omapdrm sees those, and, of course, must wait
> until their respective drivers have probed. If you don't have the
> display driver enabled, it's never loaded and omapdrm never probes as it
> keeps waiting for those.

Could you at least print some kind of message early in the boot ("omapdrm
is waiting for drivers for display x and y")?

A.