I update texture by glTexDirectVIVMap, there may be tearing on screen.
I check the message from
I test kernel version 3.14.28 and 3.14.52 with different number of FB-buffers.
bellow are my test result:
kernel=3.14.28 FB_MULTI_BUFFER=1 HSYNC abnormal
kernel=3.14.28 FB_MULTI_BUFFER=2 HSYNC ok
kernel=3.14.28 FB_MULTI_BUFFER=3 HSYNC ok
kernel=3.14.52 FB_MULTI_BUFFER=1 HSYNC abnormal
kernel=3.14.52 FB_MULTI_BUFFER=2 HSYNC abnormal
kernel=3.14.52 FB_MULTI_BUFFER=3 HSYNC ok
It's seems the GPU performance is turn to bad while upgrade it's version to
The question is : Why the new GPU version need one more buffer to solve the HSYNC problem?
One more buffer mean bad frame delay.
How to solve this problem with FB_MULTI_BUFFER=2 on new GPU version?