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I have a Motorola Atrix Lapdock connected to my Raspberry Pi using the instructions provided on various web sites including http://rpidock.blogspot.com/.

The HDMI output initially displays on the Lapdock, but if I close the Lapdock and reopen it the video will not display. I find that sometimes rebooting the Pi or completely disconnecting the Lapdock (both USB and HDMI connections) will cause the display to work again.

I've even tried setting "hdmi_safe=1" to get the display to consistently work after closing and reopening the Lapdock or rebooting the Pi.

Could I just have a flaky Lapdock? I guess that I need to connect the Lapdock to a different HDMI source to see it behaves opening and closing the Lapdock.

Are there any other config.txt commands that I should try?

Are there any command line commands that I can run while SSH'ed into my Pi to check the status of the HDMI output?



Update (2013-07-16):

Can anyone with a working Lapdock perform the tvservice -d edit.out command parsing the output using edidparser edid.out posting your results here for comparison?

Using the tvservice -d edid.outcommand I was able to dump the EDID information from my Lapdoc, here is what that was returned:

johnma@raspberrypi:~$ edidparser edid.out
Enabling fuzzy format match...
Parsing d.out...
HDMI:EDID version 1.3, 1 extensions, screen size 26x14 cm
HDMI:EDID features - videodef 0x80 !standby !suspend !active off; colour encoding:RGB444|YCbCr422; sRGB is not default colourspace; preferred format is native; does not support GTF
HDMI:EDID found monitor S/N descriptor tag 0xff
HDMI:EDID found monitor range descriptor tag 0xfd
HDMI:EDID monitor range offsets: V min=0, V max=0, H min=0, H max=0
HDMI:EDID monitor range: vertical is 50-75 Hz, horizontal is 30-85 kHz, max pixel clock is 150 MHz
HDMI:EDID monitor range does not support GTF
HDMI:EDID found monitor name descriptor tag 0xfc
HDMI:EDID monitor name is MotoAttach
HDMI:EDID found preferred DMT detail timing format: 1366x768p @ 60 Hz (86)
HDMI:EDID established timing I/II bytes are 00 00 00
HDMI:EDID standard timings block x 8: 0x0101 0101 0101 0101 0101 0101 0101 0101
HDMI:EDID parsing v3 CEA extension 0
HDMI:EDID monitor support - underscan IT formats:no, basic audio:yes, yuv444:yes, yuv422:yes, #native DTD:1
HDMI:EDID found DMT detail timing format: 1366x768p @ 60 Hz (86)
HDMI:EDID failed to find a matching detail format for 0x720p hfp:110 hs:40 hbp:-134 vfp:5 vs:5 vbp:20 pixel clock:0 MHz
HDMI:EDID calculated refresh rate is 0 Hz
HDMI:EDID guessing the format to be 0x720p @24 Hz
HDMI:EDID found unknown detail timing format: 0x720p hfp:110 hs:40 hbp:-134 vfp:5 vs:5 vbp:20 pixel clock:0 MHz
HDMI:EDID failed to find a matching detail format for 0x1080i hfp:88 hs:44 hbp:-116 vfp:2 vs:5 vbp:16 pixel clock:0 MHz
HDMI:EDID calculated refresh rate is 0 Hz
HDMI:EDID guessing the format to be 0x1080i @24 Hz
HDMI:EDID found unknown detail timing format: 0x1080i hfp:88 hs:44 hbp:-116 vfp:2 vs:5 vbp:16 pixel clock:0 MHz
HDMI:EDID found CEA format: code 1, 640x480p @ 60Hz
HDMI:EDID found CEA format: code 3, 720x480p @ 60Hz
HDMI:EDID found CEA format: code 18, 720x576p @ 50Hz
HDMI:EDID found audio format 2 channels PCM, sample rate: 32|44|48|96|192 kHz, sample size: 16|20|24 bits
HDMI:EDID found HDMI VSDB length 5
HDMI:EDID HDMI VSDB has physical address 1.0.0.0
HDMI:EDID HDMI VSDB has no extension fields
HDMI:EDID adding mandatory support for DMT (4) 640x480p @ 60Hz
HDMI:EDID adding mandatory support for CEA (2) 720x480p @ 60Hz
HDMI:EDID adding mandatory support for CEA (17) 720x576p @ 50Hz
HDMI:EDID filtering formats with pixel clock > 162 MHz or h. blanking > 1023
HDMI:EDID best score mode initialised to DMT (4) 640x480p @ 60 Hz with pixel clock 25 MHz (score 0)
HDMI:EDID best score mode is now CEA (1) 640x480p @ 60 Hz with pixel clock 25 MHz (score 43432)
HDMI:EDID best score mode is now CEA (2) 720x480p @ 60 Hz with pixel clock 27 MHz (score 45736)
HDMI:EDID CEA mode (3) 720x480p @ 60 Hz with pixel clock 27 MHz has a score of 45736
HDMI:EDID DMT mode (4) 640x480p @ 60 Hz with pixel clock 25 MHz has a score of 36864
HDMI:EDID CEA mode (17) 720x576p @ 50 Hz with pixel clock 27 MHz has a score of 45736
HDMI:EDID CEA mode (18) 720x576p @ 50 Hz with pixel clock 27 MHz has a score of 45736
HDMI:EDID best score mode is now DMT (86) 1366x768p @ 60 Hz with pixel clock 72 MHz (score 5188835)
HDMI:EDID preferred mode remained as DMT (86) 1366x768p @ 60 Hz with pixel clock 72 MHz
HDMI:EDID has HDMI support and audio support
edid_parser exited with code 0



Update (2013-07-28):

Partial success! I am able to get the display to work consistently if I execute the following commands:

tvservice -e "DMT 4"

That commands sets the following profile:

tvservice -s 
state 0x12001a [HDMI DMT (4) RGB full 4:3], 640x480 @ 60Hz, progressive

Then to get the display to appear I need to execute the following frame buffer command:

fbset 640x480-60

fbset --show

mode "640x480-60"
    # D: 25.175 MHz, H: 31.469 kHz, V: 59.940 Hz
    geometry 640 480 640 480 8
    timings 39722 48 16 33 10 96 2
    accel true
    rgba 8/0,8/0,8/0,0/0
endmode

I am, however, unable to get the display to work consistently at its native resolution of 1366x768. My /etc/fb.modes file does not contain any entry for 1366x768.

Can someone with a working Atrix lapdock post the output of the following command:

fbset --show

Thank you!



Update (2013-07-30):

More success!

I am able to reliably get the Lapdock to display HDMI video using 1280x720 resolution. I achieve this using the following parameters in my /boot/config.txt file:

# Force DMT mode 85 HDMI
hdmi_group=2
hdmi_mode=85
hdmi_drive=2

# Ignore the devices EDID information
hdmi_ignore_edid=0xa5000080


tvservice -s returns:

state 0x12001a [HDMI DMT (85) RGB full 16:9], 1280x720 @ 60Hz, progressive


fbset --show returns:

mode "1280x720"
    geometry 1280 720 1280 720 16
    timings 0 0 0 0 0 0 0
    rgba 5/11,6/5,5/0,0/16
endmode

I get no video display when using DMT mode (86) 1366x768 @ 60Hz which is supposed to be the native size of the display.

Could this be a problem with my HDMI cable connection? Could my exising HDMI cable and HDMI micro adapter have some bandwidth limitation that is preventing 1366x768 resolution from being displayed?

3

I got my lapdock (100 model) to work in mode 81 regardless of whether I used a micro-hdmi coupler with cable or just an adaptor.

## 1366x768 @ 60Hz ##
hdmi_force_hotplug=1
hdmi_group=2
hdmi_mode=81

I have yet to get it working in 720p mode, which is apparently the only way to get audio working over HDMI (according to this page - https://motorola-global-portal.custhelp.com/app/answers/prod_answer_detail/a_id/71856/p/7980,8212/action/auth)

For comparison, here is my EDID parser output ...

Enabling fuzzy format match...
Parsing edid.dat2...
HDMI:EDID version 1.3, 1 extensions, screen size 22x13 cm
HDMI:EDID features - videodef 0x80 standby suspend active off; colour encoding:RGB444|YCbCr422; sRGB is not default colourspace; preferred format is native; does not support GTF
HDMI:EDID found monitor S/N descriptor tag 0xff
HDMI:EDID found monitor name descriptor tag 0xfc
HDMI:EDID monitor name is MotoLD2S_____þ
HDMI:EDID does not yet know monitor vertical range, setting to default 24 to 120Hz
HDMI:EDID failed to find a matching detail format for 1366x768p hfp:59 hs:39 hbp:96 vfp:5 vs:9 vbp:24 pixel clock:72 MHz
HDMI:EDID calculated refresh rate is 57 Hz
HDMI:EDID guessing the format to be 1366x768p @60 Hz
HDMI:EDID found preferred DMT detail timing format: 1366x768p @ 60 Hz (81)
HDMI:EDID failed to find a matching detail format for 1366x768p hfp:59 hs:39 hbp:96 vfp:5 vs:9 vbp:24 pixel clock:75 MHz
HDMI:EDID calculated refresh rate is 60 Hz
HDMI:EDID guessing the format to be 1366x768p @60 Hz
HDMI:EDID found DMT detail timing format: 1366x768p @ 60 Hz (81)
HDMI:EDID established timing I/II bytes are 00 00 00
HDMI:EDID standard timings block x 8: 0x0101 0101 0101 0101 0101 0101 0101 0101 
HDMI:EDID parsing v3 CEA extension 0
HDMI:EDID monitor support - underscan IT formats:no, basic audio:yes, yuv444:yes, yuv422:yes, #native DTD:0
HDMI:EDID failed to find a matching detail format for 1366x768p hfp:59 hs:39 hbp:96 vfp:5 vs:9 vbp:24 pixel clock:72 MHz
HDMI:EDID calculated refresh rate is 57 Hz
HDMI:EDID guessing the format to be 1366x768p @60 Hz
HDMI:EDID found DMT detail timing format: 1366x768p @ 60 Hz (81)
HDMI:EDID failed to find a matching detail format for 1366x768p hfp:59 hs:39 hbp:96 vfp:5 vs:9 vbp:24 pixel clock:75 MHz
HDMI:EDID calculated refresh rate is 60 Hz
HDMI:EDID guessing the format to be 1366x768p @60 Hz
HDMI:EDID found DMT detail timing format: 1366x768p @ 60 Hz (81)
HDMI:EDID failed to find a matching detail format for 1366x768p hfp:59 hs:39 hbp:96 vfp:5 vs:9 vbp:24 pixel clock:72 MHz
HDMI:EDID calculated refresh rate is 57 Hz
HDMI:EDID guessing the format to be 1366x768p @60 Hz
HDMI:EDID found DMT detail timing format: 1366x768p @ 60 Hz (81)
HDMI:EDID failed to find a matching detail format for 1366x768p hfp:59 hs:39 hbp:96 vfp:5 vs:9 vbp:24 pixel clock:72 MHz
HDMI:EDID calculated refresh rate is 57 Hz
HDMI:EDID guessing the format to be 1366x768p @60 Hz
HDMI:EDID found DMT detail timing format: 1366x768p @ 60 Hz (81)
HDMI:EDID failed to find a matching detail format for 1366x768p hfp:59 hs:39 hbp:96 vfp:5 vs:9 vbp:24 pixel clock:72 MHz
HDMI:EDID calculated refresh rate is 57 Hz
HDMI:EDID guessing the format to be 1366x768p @60 Hz
HDMI:EDID found DMT detail timing format: 1366x768p @ 60 Hz (81)
HDMI:EDID found CEA format: code 2, 720x480p @ 60Hz 
HDMI:EDID found audio format 2 channels PCM, sample rate: 44 kHz, sample size: 16 bits
HDMI:EDID found HDMI VSDB length 5
HDMI:EDID HDMI VSDB has physical address 1.0.0.0
HDMI:EDID HDMI VSDB has no extension fields
HDMI:EDID adding mandatory support for DMT (4) 640x480p @ 60Hz
HDMI:EDID adding mandatory support for CEA (1) 640x480p @ 60Hz
HDMI:EDID adding mandatory support for CEA (3) 720x480p @ 60Hz
HDMI:EDID filtering formats with pixel clock > 162 MHz or h. blanking > 1023
HDMI:EDID best score mode initialised to DMT (4) 640x480p @ 60 Hz with pixel clock 25 MHz (score 0)
HDMI:EDID best score mode is now CEA (1) 640x480p @ 60 Hz with pixel clock 25 MHz (score 43432)
HDMI:EDID best score mode is now CEA (2) 720x480p @ 60 Hz with pixel clock 27 MHz (score 45736)
HDMI:EDID CEA mode (3) 720x480p @ 60 Hz with pixel clock 27 MHz has a score of 45736
HDMI:EDID DMT mode (4) 640x480p @ 60 Hz with pixel clock 25 MHz has a score of 36864
HDMI:EDID best score mode is now DMT (81) 1366x768p @ 60 Hz with pixel clock 85 MHz (score 5188835)
HDMI:EDID preferred mode remained as DMT (81) 1366x768p @ 60 Hz with pixel clock 85 MHz
HDMI:EDID has HDMI support and audio support
edid_parser exited with code 0
1

The micro female HDMI to micro male HDMI cable that I was using was the root cause of my problem.
enter image description here

When using that cable I could only achieve a maximum resolution of 1280x720.

Using only this adapter I am able to use the native resolution of the lapdock which is 1366x768. I am also able to reliably get a video display after closing and reopening the lapdock.

enter image description here

I also updated my firmware to version #518 PREEMPT Fri Aug 2 11:39:53 BST 2013 armv6l.

1
  • This post has helped me a lot. Thx. What precisely was wrong with the wiring of the cable? Have you dissected it to find out. Was it a missing GND? Feb 16 '15 at 20:15

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