LVDS display not always working [SOLVED]

Moderators: Oren.R, Eran.M

PeterSteinberg
Posts: 16
Joined: Fri Aug 26, 2016 10:20 pm
Location: Madison, WI USA

LVDS display not always working [SOLVED]

Postby PeterSteinberg » Fri Jul 28, 2017 7:07 pm

We've got a couple of SOM modules that often fail to enable the display when booting.

i.MX6 quad, Marshmallow based on android_M6.0.1_2.1.0

Looking at console log, I see the following errors:
mxc_sdc_fb fb@0: timeout when waiting for flip irq
mxc_sdc_fb fb@0: MXCFB_WAIT_FOR_VSYNC: timeout 0

The "MXCFB_WAIT_FOR_VSYNC" timeout occurs quite frequently, the "timeout when waiting for flip irq" happens much less frequently.

I've seen some posts about similar issues on the NXP site but they seem to be connected with having a splash screen dispayed by u-boot and keeping it displayed during the Android boot.

We are not displaying a splash-screen until the Android bootAnimation is activated.

Thanks,
Peter Steinberg

varigigi
Posts: 52
Joined: Tue Nov 01, 2016 10:25 am

Re: LVDS display not always working

Postby varigigi » Fri Jul 28, 2017 7:21 pm

Hi Peter,
is there any specific condition that help to reproduce the problem?
I tried several reboot, with and without the display, but I'm not able to get those messages.
Could you please share the full boot log from serial console?

Thanks
BR
Pier

PeterSteinberg
Posts: 16
Joined: Fri Aug 26, 2016 10:20 pm
Location: Madison, WI USA

Re: LVDS display not always working

Postby PeterSteinberg » Fri Jul 28, 2017 7:51 pm

It's only happening on a couple of SOM modules, and not on every boot.

A full boot log is attached.
Attachments
log.txt
(38.42 KiB) Downloaded 331 times

varigigi
Posts: 52
Joined: Tue Nov 01, 2016 10:25 am

Re: LVDS display not always working

Postby varigigi » Fri Jul 28, 2017 8:21 pm

Hi Peter,
thanks for the log.
As far as I can see you are using a custom panel, am I right?
I can see some unexpected messages as
imx-ipuv3 2800000.ipu: WARNING: adapt panel end blank lines
This could be originated by a not completely correct display definition within the device tree.

Can you try the problematic SOMs with Variscite EVK and official Android from recovery SD v72?

Thanks
BR
Pier

PeterSteinberg
Posts: 16
Joined: Fri Aug 26, 2016 10:20 pm
Location: Madison, WI USA

Re: LVDS display not always working

Postby PeterSteinberg » Fri Jul 28, 2017 8:41 pm

I will give it a try on an EVK with the recovery image. It probably won't happen until Monday.

Thanks,
Peter

PeterSteinberg
Posts: 16
Joined: Fri Aug 26, 2016 10:20 pm
Location: Madison, WI USA

Re: LVDS display not always working

Postby PeterSteinberg » Mon Jul 31, 2017 4:40 pm

The "imx-ipuv3 2800000.ipu: WARNING: adapt panel end blank lines" warning occurs because the code expects a minimum vertical lower_margin (front_porch) of 2.

Change this value to 2 (or 8) makes no difference.

I cannot use the EVK that I have with these SOM's. My EVK has a version 1 SOM (v1.22) and we are using version 2 SOM's (v2.11).

When I put the V2 SOM in the EVK it does not boot.

varigigi
Posts: 52
Joined: Tue Nov 01, 2016 10:25 am

Re: LVDS display not always working

Postby varigigi » Mon Jul 31, 2017 11:05 pm

Hi Paul,
if you remove the SoM from your EVK, very close to pin 40 of the socket, you should see a resistor named R93.
If you remove it, the EVK should boot with both V1 and V2 SoMs.

BR
Pier

PeterSteinberg
Posts: 16
Joined: Fri Aug 26, 2016 10:20 pm
Location: Madison, WI USA

Re: LVDS display not always working

Postby PeterSteinberg » Tue Aug 01, 2017 1:15 pm

Attached is the full boot log of a filed boot when installed in the EVK and programmed with mx6-som-recovery-sd.v72.img
Attachments
log.txt
(24.71 KiB) Downloaded 334 times

PeterSteinberg
Posts: 16
Joined: Fri Aug 26, 2016 10:20 pm
Location: Madison, WI USA

Re: LVDS display not always working

Postby PeterSteinberg » Tue Aug 08, 2017 9:44 pm

Any ideas on the resolution of this issue?

Thanks,
Peter

varigigi
Posts: 52
Joined: Tue Nov 01, 2016 10:25 am

Re: LVDS display not always working

Postby varigigi » Fri Aug 11, 2017 2:22 pm

Hi Peter,
I've just sent you a private mail.

Thanks
BR
Pier


Return to “Android”

Who is online

Users browsing this forum: No registered users and 2 guests