About tearing issue with OpenGL + X11 in i.MX6DQ.

[keitanagashima]

Dear All,

Hello. I have a question about tearing issue with OpenGL + X11 in i.MX6DQ.

BSP : L3.14.28_1.0.0

Environment : OpenGL + X11

[Issue]

The tearing occurs when waiting for VSYNC and displaying.

  #define MXCFB_WAIT_FOR_VSYNC    _IOW('F', 0x20, u_int32_t)

  ioctl(fd_, MXCFB_WAIT_FOR_VSYNC, 0);

This Phenomenon looks below issue.

Refer to 6.1.7  Tearing in i.MX 6 Graphics User’s Guide, Rev. 0, 12/2015

There is description of "This tearing free feature will be described in next release.".

But, the below information seem to already fix this issue.

See Comment 4.

https://bugzilla.yoctoproject.org/show_bug.cgi?id=6760

[Question]

When is this tearing issue fixed?

(Or, which BSP version was it fixed?)

Best regards,

Keita

[Bio_TICFSL · Accepted solution]

Hi Keita,

Tearing is a known X11 problem, in fact it is an X11 architecture problem. So far there is no any official fix for X11 tearing issue with vsync, however several gpu bug fixed have been added to 3.14.28-1.0.1 patch such as: gitorious.org Git - efikamx:linux-kernel.git/commit  using export FB_MULTIBUFFER option, however X11 EGL is single buffered and there is no support for VSYNC.

Please check the 3.14.28-1.0.1 patch release notes for more information

http://www.nxp.com/files/32bit/doc/support_info/IMX6L31428101RN.pdf

Regards