Hi,
On 18/10/2024 12:32, Geert Uytterhoeven wrote:
Hi all,
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
--------------
0. General:
- Hotplug detect does not work, switching display needs a reboot,
Right. It's an eDP chip, and the driver seems to be made to really only
support eDP.
I'm not so familiar with the HW that I could say if DP HPD can be
properly implemented or not (I've seen eDP chips that have had issues
there...), but with a quick test one can do:
rwmem --i2c=1:0x2c -s8 -S8 0x5c:0=0
to enable the HPD, and then it seems to work. However, the driver
doesn't support interrupts and uses DRM's polling, so it takes a while
for the framework to notice the disconnect.
But if you run a command that does a display probe, say "kmsprint" from
kms++, it'll update the status right away.
So, as far as I can see, without actually properly looking at it, it
should be doable to improve the sn65dsi86 driver to support HPD too.
- fbtest test002 crashes with SEGV in 2560x1440.
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
- 1920x1080 is stable
2. Mini-DP to (C) to (A) HDMI:
- 2560x1440 OK
- 1920x1080 OK
3. Mini-DP to (C) to (B) mini-HDMI:
- 1920x1080 OK
4. Mini-DP to (C) to (A) HDMI + (B) mini-HDMI:
- 1920x1080 mirrored OK
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)?
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.
Tomi
White Hawk CN15
---------------
Does not work:
- Display resolution is detected correctly (1920x1080 or 2560x1440),
- Black screen, displays say no signal detected,
- "modetest -M rcar-du -s 88:1920x1080@XR24" triggers:
rcar-mipi-dsi fed90000.dsi-encoder: Failed to disable video transmission
vsp1 fea20000.vsp: Underrun occurred at WPF0 (total underruns 2)
Note that fea20000.vsp is vspd0, not vspd1. I do have a few similar
messages for fea28000.vsp in my logs, so this may be a red herring.
Thanks for your comments!
Geert Uytterhoeven (1):
arm64: dts: renesas: white-hawk: Add mini-DP output support
.../boot/dts/renesas/r8a779g0-white-hawk.dts | 90 +++++++++++++++++++
1 file changed, 90 insertions(+)
