Difference between revisions of "LVDS"

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If the LVDS display card has been created, it would create a sysfs debug directory.
 
If the LVDS display card has been created, it would create a sysfs debug directory.
<pre><code>$ ls /sys/class/drm/card0-LVDS-1</code>
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<pre>$ ls /sys/class/drm/card0-LVDS-1</code>
 
</pre>
 
</pre>
  
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== Check LVDS display card status: status, enabled, modes ==
 
== Check LVDS display card status: status, enabled, modes ==
<pre><code>$ cd /sys/class/drm/card0-LVDS-1
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<pre>$ cd /sys/class/drm/card0-LVDS-1
 
$ cat status  # should printed "connected" or "disconnected"
 
$ cat status  # should printed "connected" or "disconnected"
 
$ cat enabled # should printed "enabled" or "disabled"
 
$ cat enabled # should printed "enabled" or "disabled"
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*Check the LVDS panel power supply.  
 
*Check the LVDS panel power supply.  
 
*Check the panel datasheet, ensure you have configured the timing and data format rightly.  
 
*Check the panel datasheet, ensure you have configured the timing and data format rightly.  
*Check the hardware connected status, or test the panel on workable board.  
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*Check the hardware connected status, or test the panel on workable board.
 
 
=== &nbsp; ===
 

Latest revision as of 07:37, 11 October 2017

References

source code

device-tree document

 

Tips

Whether LVDS display card has been registered successfully

If the LVDS display card has been created, it would create a sysfs debug directory.

$ ls /sys/class/drm/card0-LVDS-1</code>

So you just need to check that directory. If that directory is missing in your machine board, please check:

  • Whether LVDS have been enabled in DTS files.
  • Whether LVDS panel have been registered successfully.
  • Whether you have available VOP module for LVDS.
  • Check the kernel log for more detail (dmesg | grep lvds)

Check LVDS display card status: status, enabled, modes

$ cd /sys/class/drm/card0-LVDS-1
$ cat status  # should printed "connected" or "disconnected"
$ cat enabled # should printed "enabled" or "disabled"
$ cat modes   # should printed the available mode list, like 1536x2048</code>

If you still have no picture on LVDS panel, please check bellow information:

  • Check the LVDS panel power supply.
  • Check the panel datasheet, ensure you have configured the timing and data format rightly.
  • Check the hardware connected status, or test the panel on workable board.