[linux-yocto] Yocto xrandr output two different resolution will cause monitor abnormal

[shadow.yang]

Hello,

 

System:Bay trail-I E3826/E3827

DP to VGA bridge:CHRONTEL_CH7517A-BFI (DP1)

OS : Yocto fido 1.8 x86

Driver:I915 driver V1.6 20141121

Monitor:ViewSonic x2 VGA

BIOS mode:Legacy

Kernel 3.19.5

 

We want to output different resolution for two monitors in clone mode, one
is VGA and another is DP to VGA. if we use xrandr to output the same
resolution, the two resolutions are fine to use, but the DP to VGA screen
will fail when we set different resolution.

 

xrandr --output VGA1 --mode 1920x1024 --output DP1 --mode 1024x768 => fail

xrandr --output VGA1 --mode 1920x1024 --output DP1 --mode 1920x1024 => OK

 

attached:

DSC_0267.jpg => Overview two the same monitor

DSC_02671.jpg => Normal status

DSC_02681.jpg => Abnormal status

 

 

Regards,

shadow

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.yoctoproject.org/pipermail/linux-yocto/attachments/20150911/92dd7913/attachment.html>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: DSC_0267.jpg
Type: image/jpeg
Size: 179870 bytes
Desc: not available
URL: <http://lists.yoctoproject.org/pipermail/linux-yocto/attachments/20150911/92dd7913/attachment.jpg>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: DSC_02671.jpg
Type: image/jpeg
Size: 197711 bytes
Desc: not available
URL: <http://lists.yoctoproject.org/pipermail/linux-yocto/attachments/20150911/92dd7913/attachment-0001.jpg>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: DSC_02681.jpg
Type: image/jpeg
Size: 217487 bytes
Desc: not available
URL: <http://lists.yoctoproject.org/pipermail/linux-yocto/attachments/20150911/92dd7913/attachment-0002.jpg>