Re: [Letux-kernel] module_mipi_dsi_driver panel with omapdrm?

[David Shah <dave@ds0.me>]

Following a bit of testing, the DSI issues are fixed by 
https://github.com/daveshah1/pyra-kernel-devel/commit/3161275854a0f2cd44a55b8eb039bd201f894486
 (I will prepare a proper patch set shortly). This makes the display
work with HDMI disabled.

There also seems to be a race condition between the hdmi0 connector
and tpd12s015 "encoder". This results in the tpd12s015 permanently
returning EPROBE_DEFER and the display subsystem never successfully
probing.

Reversing the order of the encoder and connector in the device tree
(omap5-board-common.dtsi) makes the display work again with HDMI
enabled; as does adding some printks to the display-connector driver.

On Thu, 2020-08-06 at 17:04 +0100, David Shah wrote:
> Sorry, my error. I forgot the Pyra is LPAE and therefore using 64-bit
> physical addresses.
> 
> The start is indeed a correct physical address, 0x58005000, but off
> by
> 0x1000 from what the DSI driver is expecting.
> 
> On Thu, 2020-08-06 at 16:50 +0100, David Shah wrote:
> > 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@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
> > > 
> > 
> > _______________________________________________
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> 
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