Hi Tomi,
On Tue, Nov 26, 2024 at 4:58 PM Tomi Valkeinen
<tomi.valkeinen+renesas@xxxxxxxxxxxxxxxx> wrote:
> On 18/10/2024 12:32, Geert Uytterhoeven wrote:
> > As I had to test Tomi's WIP patches to add mini-DP output support to
> > Gray Hawk Single, I moved my (old and new) DisplayPort gear to my board
> > farm, and thought this was a good opportunity to test mini-DP output on
> > White Hawk as a baseline (CN5), and add support for the second mini-DP
> > output on the White Hawk BreakOut board (CN15).
> >
> > For testing, I used the following hardware:
> > (A) BenQ BL2420PT desktop display (2560x1440),
> > (B) Joy-It Joy-View 15 portable display (1920x1080),
> > (C) Lindy DisplayPort to 2 Port HDMI MST Hub,
> > (D) Passive mini-DP to HDMI cable,
> > (E) LogiLink Mini DisplayPort to VGA Converter.
> >
> > (A)-(C) are known to work with my Intel desktop.
> > (D)-(E) are known to work with an old Dell XPS13.
> >
> > Software-wise, I used the frame buffer text console, "modetest -M
> > rcar-du -s 86:1920x1080@XR24" or "modetest -M rcar-du -s
> > 86:2560x1440@XR24", and fbtest.
> >
> > White Hawk CN5
> > --------------
> > 1. Mini-DP to (A) DP:
> > - 2560x1440 works but flickers (flickering shifts image
> > horizontally; perhaps a cable issue, as 2 below does work?)
>
> I get a stable picture with my old-ish Dell monitor:
>
> # kmstest
> Connector 0/@86: DP-1
> Crtc 0/@83: 2560x1440@59.95 241.500 2560/48/32/80/+ 1440/3/5/33/- 60
> (59.95) P|D
> Plane 0/@33: 0,0-2560x1440
> Fb 97 2560x1440-XR24
> press enter to exit
Good to know! I'll see if I can try with a different cable (the
current one claims to do 8K, though).
> > 5. Mini-DP to (E) to (A) HDMI:
> > - SN65DSI86 behaves as if no cable is connected.
> > Expected, as TI SN65DSI86 does not support Dual-Mode/DP++.
> >
> > 6. Mini-DP to (D) to (A) VGA:
> > - Detected 1920x1080, black screen / no signal.
> > Perhaps this adapter relies on DP++, too?
>
> Hmm, are these two mixed up? 5. should have (D), and 6 should have (E)?
Yes they are. Sorry for that.
> No, the vga is an active one, but does it have external power source? If
> not, it relies on the power from the DP connector, and I'm not sure if
> we're providing any/enough.
The VGA adapter does not have an external power source.
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
