Re: No HDMI signal from Nitrogen6x board with daisy

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

Thanks Peter,

On 05/27/2014 11:51 PM, Peter Bergin wrote:
> Hi Eric,
>
> On 05/27/2014 11:11 PM, Eric Nelson wrote:
>> 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 have previously have the Nitrogen board running against this monitor
> and also other boards such as cgtqmx6. Your thought about silicon
> revision could be the case and the cause why we do not see the same
> behavior. Can someone at Freescale give us a hint if there are anything
> changed in this region that can cause this and if this is a valid guess?
>
> If the "old revision" guess is a probable one we don't need to spend
> more time on this (from my point of view).
>

I'd certainly like to know, since we have lots of other customers with
TO.1.0 silicon.

With this information and your EDID blob, I should be able to reproduce
things, and I'm sure I have an older board around somewhere.

>> 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 do running with only_cea flag. I think my kernel command line was cut
> in the log-file for some reason. My kernel command line looks like this:
>
> root@nitrogen6x:~# cat /proc/cmdline
> enable_wait_mode=off video=mxcfb0:dev=hdmi,1920x1080M@60,if=RGB24
> video=mxcfb1:off video=mxcfb2:off video=mxcfb3:off fbmem=28M
> dyndbg="module mxc_hdmi +pf;module mxc_hdmi_core +pf;module mxc_ipu
> +pf;module mxc_ipuv3_fb +pf" console=ttymxc1,115200 vmalloc=400M
> consoleblank=0 rootwait root=/dev/mmcblk0p2 mxc_hdmi.only_cea=1
>
> When looking in the driver code what the only_cea mode flag does is that
> it will only add CEA modes to the mode list. This is the cause why in
> the first case had 15 "standard" timings but in the second run after
> enabling the only_cea flag only have 8.
>

Okay. I'm still confused about why the kernel decided to use
"DVI" mode.

Because of this, the kernel didn't configure an audio channel
as shown in my equivalent output:

nitrogen6x user.debug kernel: mxc_hdmi_setup: mxc_hdmi 
20e0000.hdmi_video: mxc_hdmi_setup CEA mode
nitrogen6x user.debug kernel: hdmi_set_clk_regenerator: 
hdmi_set_clk_regenerator: samplerate=48000  ratio=100 
pixelclk=148500000  N=6144  cts=148500
nitrogen6x user.debug kernel: hdmi_enable_audio_clk: mxc_hdmi 
20e0000.hdmi_video: hdmi_enable_audio_clk
nitrogen6x user.debug kernel: hdmi_config_AVI: mxc_hdmi 
20e0000.hdmi_video: set up AVI frame
nitrogen6x user.debug kernel: mxc_hdmi_setup: mxc_hdmi 
20e0000.hdmi_video: mxc_hdmi_setup exit

>>> 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.
> Here is a dump of EDID from my monitor. It is a Samsung SyncMaster B2440.
>

Thanks. This is helpful.

> U-Boot > i2c dev 1
> Setting bus to 1
> U-Boot > i2c md 50 0.1 200
> 0000: 00 ff ff ff ff ff ff 00 4c 2d 9f 06 34 32 42 43    ........L-..42BC
> 0010: 2c 14 01 03 80 34 1d 78 2a ee d1 a5 55 48 9b 26    ,....4.x*...UH.&
> 0020: 12 50 54 bf ef 80 81 00 81 40 81 80 95 00 a9 40    .PT......@.....@
> 0030: b3 00 71 4f 95 0f 02 3a 80 18 71 38 2d 40 58 2c    ..qO...:..q8-@X,
> 0040: 45 00 09 25 21 00 00 1e 00 00 00 fd 00 38 4b 1e    E..%!........8K.
> 0050: 51 11 00 0a 20 20 20 20 20 20 00 00 00 fc 00 53    Q...      .....S
> 0060: 4d 42 32 34 34 30 4c 0a 20 20 20 20 00 00 00 ff    MB2440L.    ....
> 0070: 00 48 39 58 5a 42 30 30 34 37 35 0a 20 20 01 a1    .H9XZB00475.  ..
> 0080: 02 01 04 00 02 3a 80 d0 72 38 2d 40 10 2c 45 80    .....:..r8-@.,E.
> 0090: 09 25 21 00 00 1e 01 1d 00 72 51 d0 1e 20 6e 28    .%!......rQ.. n(
> 00a0: 55 00 09 25 21 00 00 1e 01 1d 00 bc 52 d0 1e 20    U..%!.......R..
> 00b0: b8 28 55 40 09 25 21 00 00 1e 8c 0a d0 90 20 40    .(U@.%!....... @
> 00c0: 31 20 0c 40 55 00 09 25 21 00 00 18 8c 0a d0 8a    1 .@U..%!.......
> 00d0: 20 e0 2d 10 10 3e 96 00 09 25 21 00 00 18 00 00     .-..>...%!.....
> 00e0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00    ................
> 00f0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 5e    ...............^
> 0100: 00 ff ff ff ff ff ff 00 4c 2d 9f 06 34 32 42 43    ........L-..42BC
> 0110: 2c 14 01 03 80 34 1d 78 2a ee d1 a5 55 48 9b 26    ,....4.x*...UH.&
> 0120: 12 50 54 bf ef 80 81 00 81 40 81 80 95 00 a9 40    .PT......@.....@
> 0130: b3 00 71 4f 95 0f 02 3a 80 18 71 38 2d 40 58 2c    ..qO...:..q8-@X,
> 0140: 45 00 09 25 21 00 00 1e 00 00 00 fd 00 38 4b 1e    E..%!........8K.
> 0150: 51 11 00 0a 20 20 20 20 20 20 00 00 00 fc 00 53    Q...      .....S
> 0160: 4d 42 32 34 34 30 4c 0a 20 20 20 20 00 00 00 ff    MB2440L.    ....
> 0170: 00 48 39 58 5a 42 30 30 34 37 35 0a 20 20 01 a1    .H9XZB00475.  ..
> 0180: 02 01 04 00 02 3a 80 d0 72 38 2d 40 10 2c 45 80    .....:..r8-@.,E.
> 0190: 09 25 21 00 00 1e 01 1d 00 72 51 d0 1e 20 6e 28    .%!......rQ.. n(
> 01a0: 55 00 09 25 21 00 00 1e 01 1d 00 bc 52 d0 1e 20    U..%!.......R..
> 01b0: b8 28 55 40 09 25 21 00 00 1e 8c 0a d0 90 20 40    .(U@.%!....... @
> 01c0: 31 20 0c 40 55 00 09 25 21 00 00 18 8c 0a d0 8a    1 .@U..%!.......
> 01d0: 20 e0 2d 10 10 3e 96 00 09 25 21 00 00 18 00 00     .-..>...%!.....
> 01e0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00    ................
> 01f0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 5e    ...............^
> U-Boot >
>
>
>>> 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.
>>>
>
> One further observation I have done is regarding the clock source in the
> IPU. When running the working 640x480 resolution the IPU clock is
> internal but when running other non-working resolution the clock source
> is external (PLL5 ?). Could this be something that cause my problem?
>

Perhaps, but the clock divisors appeared to be the same as what
I saw in a working unit.

Regards,


Eric