Difference between revisions of "Jetson TX2/28 Display debug"

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(Tips)
(Tips)
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# set use_fallback = true; in tegra_edid_get_monspecs() under edid.c.
 
# set use_fallback = true; in tegra_edid_get_monspecs() under edid.c.
 
# fill in the known EDID to default_720p_edid[256].
 
# fill in the known EDID to default_720p_edid[256].
 +
 +
*Blank/Unblank window/display
 +
sudo  echo 4 > /sys/class/graphics/fb0/blank  #blank display and power down
 +
sudo  echo 1 > /sys/class/graphics/fb0/blank  #blank display and show the background color
 +
sudo  echo 0 > /sys/class/graphics/fb0/blank
  
 
==Known issues==
 
==Known issues==

Revision as of 00:03, 9 January 2018

Get prepared

This section focuses on debug display driver issue on rel-28.x release.
Drivers of tegra display controller are under kernel source: https://developer.nvidia.com/embedded/downloads
Location:
For T210(TX1)
kernel/display/drivers/video/tegra/dc/
For T186(TX2). Note that TX2 still uses driver code of T210.
kernel/t18x/drivers/video/tegra/dc

Tips

  • Print current mode in dc
sudo cat /sys/kernel/debug/tegradc.X/mode  #X=0,1,2.
  • Print current mode in fbcon
sudo cat /sys/class/graphics/fb0/mode  #if more than one fb, just change the fbX to whatever you want.
  • Capture edid
sudo cat /sys/kernel/debug/tegradc.X/edid  #X=0,1,2.
  • Forcing edid
  1. Prepare a known 256byte EDID.
  2. set use_fallback = true; in tegra_edid_get_monspecs() under edid.c.
  3. fill in the known EDID to default_720p_edid[256].
  • Blank/Unblank window/display
sudo  echo 4 > /sys/class/graphics/fb0/blank  #blank display and power down
sudo  echo 1 > /sys/class/graphics/fb0/blank  #blank display and show the background color
sudo  echo 0 > /sys/class/graphics/fb0/blank

Known issues