AnsweredAssumed Answered

HDMI hotplug issue

Question asked by Bala Subramaniyam on May 29, 2018
Latest reply on Jun 11, 2018 by Bala Subramaniyam

HI,

I am using the yocto Morty release and Linux 4.9 kernel.

I am booting the device without connecting HDMI. When I connect the HDMI display to the device after device is booted, the HDMI display screen is streached or corrupted.
Note:
* In u-boot, display boot args is set for HDMI display

 

To debug this issue I'm checking the HDMI supported video modes from xrandr and sys.

 

Video modes before HDMI connected:

$ cat /sys/class/graphics/fb0/modes$ xrandr
U:1920x1080p-60
V:1152x864p-75
V:1280x1024p-60
V:1024x768p-75
V:1024x768p-60
V:800x600p-75
V:800x600p-60
V:640x480p-75
V:640x480p-60
U:1280x720p-120
U:1280x720p-100
U:1920x1080p-30
U:1920x1080p-25
U:1920x1080p-24
U:1920x1080p-50
U:1440x576p-50
U:1440x576p-50
U:1440x288p-50
U:1440x288p-50
U:1280x720p-50
U:720x576p-50
U:720x576p-50
U:1920x1080p-60
U:1440x480p-60
U:1440x480p-60
U:1440x240p-60
U:1440x240p-60
U:1280x720p-60
U:720x480p-60
U:720x480p-60
U:640x480p-60
Screen 0: minimum 240 x 240, current 1920 x 1080, maximum 8192 x 8192
DISP3 BG connected 1920x1080+0+0 (normal left inverted right x axis y axis) 0mm x 0mm
U:1920x1080p-60 60.00*+
U:1920x1080p-50 50.00
U:1920x1080p-30 30.00
U:1920x1080p-25 25.00
U:1920x1080p-24 24.00
V:1280x1024p-60 60.02
V:1152x864p-75 75.00
U:1280x720p-120 120.00
U:1280x720p-100 100.00
U:1280x720p-50 50.00
U:1280x720p-60 60.00
U:1440x576p-50 50.00
V:1024x768p-75 75.08
V:1024x768p-60 60.01
U:1440x480p-60 60.00
V:800x600p-75 75.00
V:800x600p-60 60.32
U:1440x288p-50 50.08
U:720x576p-50 50.00
U:720x480p-60 59.94
U:1440x240p-60 59.94
V:640x480p-75 75.00
V:640x480p-60 60.00
U:640x480p-60 59.94

 

 

Video modes after HDMI connected:

Video modes in sys entry updated after HDMI connected, but Xrandr is not updating. Is that make any HDMI display screen streched issue.

$ cat /sys/class/graphics/fb0/modes
S:1920x1080p-50
S:1280x720p-50
S:720x576p-50
S:720x576p-50
S:1920x1080p-60
S:1280x720p-60
S:720x480p-60
S:720x480p-60
S:640x480p-60
S:1152x864p-75
S:1280x1024p-60
V:1024x768p-60
V:800x600p-60
V:640x480p-60
D:1920x1080p-60
V:640x480p-60

 

After I restarted the Xserver, both xrandr & sys entry video modes are common and now the hotplug issue is not recreating untill reboot the device.

 

Is it a know issue or is there any patch is available to solve this issue.

 

Best regarsd,

Bala

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