[Letux-kernel] module_mipi_dsi_driver panel with omapdrm?

[David Shah]

I had a moment to give letux-5.7.y a test on the Pyra hardware.

I notice an error in dmesg:

 DSI: omapdss DSI error: unsupported DSI module

which comes from this code (with a small patch added by me):

	d = dsi->data->modules;
	while (d->address != 0 && d->address != dsi_mem->start)
		d++;

	if (d->address == 0) {
		DSSERR("unsupported DSI module (start: %08x)\n",
dsi_mem->start);
		return -ENODEV;
	}

"start" here is c0b3ba5c - a kernel virtual address - which definitely
doesn't seem right as it would never match. 

Not sure my kernel-fu is quite up to tracking this down yet, but I will
keep trying to trace out what is happening.

Best

Davidg

On Wed, 2020-08-05 at 15:08 +0300, Tomi Valkeinen wrote:
> On 05/08/2020 14:49, H. Nikolaus Schaller wrote:
> > Hi,
> > 
> > > Am 05.08.2020 um 13:28 schrieb Sebastian Reichel <
> > > sebastian.reichel at collabora.com>:
> > > 
> > > Hi,
> > > 
> > > On Wed, Aug 05, 2020 at 11:19:20AM +0200, H. Nikolaus Schaller
> > > wrote:
> > > > What I do not yet understand is how Laurent's patch should be
> > > > able
> > > > to break it.
> > > 
> > > omapdrm will not probe successfully if any DT enabled component
> > > does not probe correctly. Since the patch you identified touched
> > > HDMI and VENC and you are probably using HDMI, I suggest looking
> > > there first.
> > 
> > Yes, that is a very good explanation.
> > 
> > Maybe there is a subtle change in how the HDMI connector has to be
> > defined
> > which is missing in our (private) DTB. Maybe the OMAP5-uEVM DTS
> > gives a hint.
> > 
> > A quick check shows last hdmi specific change for omap5-board-
> > common or uevm
> > was in 2017 but I may have missed something.
> > 
> > There are 715a5a978733f0 and 671ab615bd507f which arrived in v5.7-
> > rc1 as well
> > and are related to hdmi clocks. So this may be (or not) and
> > influencing factor.
> 
> HDMI should "just work", and has been tested. But maybe there's some
> conflict with HDMI and DSI.
> 
>  Tomi
>