Re: No HDMI signal from Nitrogen6x board with daisy

[Eric Nelson <eric.nelson@boundarydevices.com>]

Hi Peter,

On 05/25/2014 11:43 PM, Peter Bergin wrote:
> Hi Eric,
>
>  <snip>
>
> In order to understand more what happens during the process I have
> enabled dynamic debug in the kernel and turned on messages from mxc_hdmi
> and mxc_ipu. I have attached my /var/log/messages if someone more
> familiar with the drivers can have a look.
>

Thanks for the detailed information.

> IPU_INT_STAT_5 is classed as Error Interrupts in the Reference Manual.
>
> May 26 06:02:30 nitrogen6x user.warn kernel: imx-ipuv3 2400000.ipu: IPU
> Warning - IPU_INT_STAT_5 = 0x00800000
>
> This seems to be a IMDAC_NFB4EOF_ERR_x. NFB4EOF - New-frame before
> end-of-frame.
>
> How can I get more understanding what's wrong in the IPU? Any ideas?
>

Nothing concrete. Perhaps the Freescaler's have some idea.

The only time I've seen the NFB4EOF error has been when I've
had a bug (in a camera driver). I believe it means that there's
an initialization problem.


I've been trying to compare against what I see here,
and the two primary suspects are:

	- some quirk of your EDID
	- the fact that you're running an older processor revision
	(TO 1.0).

I haven't yet found a TO 1.0 board to test against.

I also notice in your output that you're running without the
"only_cea" flag, and you are getting a non-CEA mode:

	mxc_hdmi_setup: mxc_hdmi 20e0000.hdmi_video: mxc_hdmi_setup DVI mode

> I have also checked /sys/class/graphics/fb0 and made some tests.
>
> root@nitrogen6x:~# cat /sys/class/graphics/fb0/mode
> D:1920x1080p-60

This is really odd, because you're not seeing all of the
modes that are reported from U-Boot (e.g. 800x600@60):
	
> root@nitrogen6x:~# cat /sys/class/graphics/fb0/modes
> D:720x480p-59
> D:720x576p-50
> D:1280x720p-50
> D:1280x720p-60
> D:1920x1080p-50
> V:640x480p-60
> D:1920x1080p-60
> V:640x480p-60
>
In your post on i.MX Community, you showed 15 "standard" timings:

	https://community.freescale.com/thread/324175

Can you forward a hex-dump of your EDID settings from
U-Boot?

U-Boot > i2c dev 1
U-Boot > i2c md 50 0.1 200
0000: 00 ff ff ff ff ff ff 00 1e 6d fb 56 01 01 01 01    .........m.V....
0010: 03 13 01 03 80 33 1d 78 0a ae c5 a2 57 4a 9c 25    .....3.x....WJ.%
0020: 12 50 54 a7 6b 80 b3 00 81 8f 81 80 71 4f 01 01    .PT.k.......qO..
0030: 01 01 01 01 01 01 1a 36 80 a0 70 38 1f 40 30 20    .......6..p8.@0
0040: 35 00 fe 22 11 00 00 1e 02 3a 80 18 71 38 2d 40    5..".....:..q8-@
0050: 53 2c 45 00 fe 22 11 00 00 1e 00 00 00 fd 00 38    S,E..".........8
0060: 3d 1e 53 0f 00 0a 20 20 20 20 20 20 00 00 00 fc    =.S...      ....
0070: 00 57 32 33 36 31 0a 20 20 20 20 20 20 20 01 61    .W2361.       .a
0080: 02 03 21 f1 4e 90 04 03 01 14 12 05 1f 10 13 00    ..!.N...........
0090: 00 00 00 23 09 07 07 83 01 00 00 65 03 0c 00 10    ...#.......e....
00a0: 00 02 3a 80 18 71 38 2d 40 58 2c 45 00 fe 22 11    ..:..q8-@X,E..".
00b0: 00 00 1e 01 1d 80 18 71 1c 16 20 58 2c 25 00 fe    .......q.. X,%..
00c0: 22 11 00 00 9e 01 1d 00 72 51 d0 1e 20 6e 28 55    ".......rQ.. n(U
00d0: 00 fe 22 11 00 00 1e 8c 0a d0 8a 20 e0 2d 10 10    .."........ .-..
00e0: 3e 96 00 fe 22 11 00 00 18 00 00 00 00 00 00 00    >..."...........
00f0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 de    ................


This might help narrow things down. We can fake the
EDID blob from there and see if we can reproduce
your symptoms.

> I have tried to set all of the above listed resolutions in modes. The
> only resolution that works is V:640x480p-60. With this resolution set I
> get signal on HDMI and the display shows my screen.
>


Also odd is that your 'mode' above shows 'D:1920x1080p-60'.
The 'D' stands for detailed, meaning that your EDID is
customizing the timings a bit from the standard.
	https://github.com/boundarydevices/linux-imx6/blob/boundary-imx_3.10.17_1.0.0_ga/drivers/video/fbsysfs.c#L105

A couple of monitors here are showing "S"tandard timings:
	root@nitrogen6x:~# cat /sys/class/graphics/fb0/modes
	...
	S:1920x1080p-60

Even though U-Boot shows "detailed" in the same manner as
your monitor:

         U-Boot > i2c edid 50
         EDID version: 1.3
         Product ID code: 56fb
         ...
         Estabilished timings:
         	...
         Standard timings:
         	...
         	1920x1080 	59 Hz (detailed)
         	1920x1080 	60 Hz (detailed)
         Monitor range limits, horizontal sync: 30-83 kHz, vertical 
refresh: 56-61 Hz, max pixel clock: 150 MHz
         Monitor name: W2361

Please advise,


Eric