Display resolution and timing

oh… shoot. my bad just had in mind the dragon board 410c for some odd reason…
yes the factory file should be good.
and yes the issue still is that hikey960 does not have release builds. they are snapshot so a lot of kinks are being worked out.
I see that you display resolution is 1440 x 900 at 60 Hz, is unique. I’ve mostly seen 1366x768 or 1920x1080 monitors so it might be that the support is limited atm.
@leo-yan may have some more info on the supported resolutions

Any guesses to when release builds will start showing up? I may just shelve this board for a few months and wait.

@Ampster, my project is to drive a MIPI based 1080 X 1920 display via either HDMI or the MIPI connector. To little avail at this time. Somewhat frustrating as I could have saved for a further two months and bought a Samsung 8 for my testing requirements.

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What is it exactly that isn’t working? Is it the mali drivers? What steps do I take to remedy the problem? I would like to contribute to fixing this, but don’t know where to start. This can be fixed, right?

My miniature screen is just blank. The MIPI controller board works indicated by the LEDs but that is as far as it goes. I’ll try and find some time later this week to give this another good jolly good looking at.
Yes, and let’s hope that we can fix this.

What are the led codes for this board?

@ric96 the TV is a philips 40pfl4707/f7

Sorry Ampster, LED code?

not in europe. Currently in VA. LED codes like…3 fast& 2 slow pulses signify thermal issue… etc. I was wondering if there are LED indicator codes that can be read if you don’t have a display that works. That isn’t a legit light code btw. That was just an example of what I meant.

News? I’m just letting this board collect dust. Lol.

Yes I know it’s Saturday night, but the family are in bed and so I get finally access to the TV in the lounge.
To confrm that the Samsung LG43 610V works fine via striaght HDMI to HDMI (ish - as the build from the 1st August on the 960 causes the display to be slightly off centred. I can’t flash it at the moment as my USB 3 C cable is back in the office at work … sigh.

Plugging it into the little 6" 1080p 60Hz LCD display and nothing is being shown. The LED on the MIPI board flashes 8 or 9 times when there isn’t any data being sent to it, i.e. when the 960 powered off. When the 960 powers up the LED remains off.

There must be an easy answer to this.

So we have a clue what might be going on here.

My monitor discloses the refresh rate of the incoming video. For hikey960 the video mode is reported as 1920x1080@58Hz but for other boards, including the hikey which uses a similar HDMI converter, the video mode is 1920x1080@60Hz. In other words we’re only like to get a display running on a display device that tolerates this refresh rate (I suspect many TVs won’t tolerate that… especially those that are for the US market only).

I’ve also found some suspicious looking code that may be responsible for this… however its sufficiently suspicious that no programmer I know would write it except to workaround something worse. So I’ll run a few experiements but…

… may prove to be optimistic :wink:

Thanks Daniel,

Ahh, it must be my sunny disposition and PMA showing through. Or I am just
niave. My board is a MIPI board so I’ve got a resolution of 1080 x 1920
@60hz. So it looks as though I am well goosed.
Unfortunately, I am not a developer\programmer (Brit spelling) and more of
a general tech, so I don’t think I am unable to help too much in this.

I have been looking at the Sony Experia ZX today. This may be the solution
to me trying to be clever and wanting to use a discrete display and minute
motherboard

With kind regards
Phil

There are more and useful discussions in https://bugs.96boards.org/show_bug.cgi?id=598

HiKey960 has hardware limitations in generating 148M clock rates for 60Hz 1080p pixels. Instead it uses 144M to mimic it.

Having seen Guodong’s update I double checked this. I’m afraid I misread the video mode from my monitor (it puts the current refresh rate side-by-side with the max refresh rate… easy to misread). The original hikey also outputs at 1920x1080@58Hz.

Hi danielt,

ist there a solution meanwhile?
I have the same problem with a samsung TV.

I’m afraid not, I’m not aware of any way to workaround this issue short of switching to an alternative display device.

You can switch to a lower resolution that is supported by the monitor, but for which the hikey is able to generate the correct clock. For instance, 1280x720. You can add a video= parameter to the kernel commandline to achieve this.

@danielt : might it not be a good idea to set a default resolution that is fully HDMI standards compliant?

It is possible the TV might react differently to different frequencies but it is likely still to “mute” the output since the clock for the other modes has a similar percent error.

Hello everyone,
I have two Hikey960 boards and using it with Samsung TV - UN55FH6030CXZA.
One still has the pre-installed version which works with the TV (Out of the box).
For the second board, I successfully built the AOSP and the HDMI doesn’t work.
I also tried Factory image, but it still won’t work.(https://www.96boards.org/documentation/consumer/hikey960/downloads/aosp.md.html)
I verified that the Display and clock rates are included for the TV, but had no luck.
(https://android-review.googlesource.com/c/kernel/hikey-linaro/+/505547/2/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c)

Any help is appreciated.