Linux/DRA724: Use drmModeSetPlane to display with full fps get tearing on GLSDK7.04

Hi Sid,

I have forwarded your question to graphics experts.

Regards,
Yordan

Hi Sid,

As discussed in the following thread, you should use drmModePageFlip to flip the buffer to display and wait for vsync:
e2e.ti.com/.../611021

To update multiple planes, atomic mode setting should be used. This is supported as part of Processor SDK Linux automotive v3.x on K4.4. You can move to the latest release v3.02 to utilize atomic mode setting:
processors.wiki.ti.com/.../Category:Processor_SDK_Linux_Automotive

Regards,
Anand

Hi Anand,
Thanks for your reply angin.
This was another project use GLSDK7.04，it will SOP in this mouth, dont have much time move to PSDK 3.02.
But we use the drmModeSetPlane ,and get tearing when the lcd refresh is 30fps, and the video in for display is 25fps .
I see some example in dual-camera-demo for glsdk , it use drmModeSetPlane like following code:
"
/* Delay queuing the buffer back to capture driver for two display buffer timing */
/* This is because drmSetModePlane() API is async and doesn't acknowldege when */
/* the buffer is done displaying. Assuming that two capture frame delays should */
/* be sufficient to ensure consumption of buffer by display and safe to be queued*/
/* to capture driver pool */
if(v4l2_device->b[0] != NULL){
v4l2_queue_buffer(v4l2_device, v4l2_device->b[0]);
}

/* Request a capture buffer from the driver that can be copied to framebuffer */
buf = v4l2_dequeue_buffer(v4l2_device);

v4l2_device->b[NBUF-1] = buf;
i = 0;
do{
v4l2_device->b[i] = v4l2_device->b[i+1];
i++;
}while(i != (NBUF-1));


if(pip) {
ret = drmModeSetPlane(drm_device->fd, drm_device->plane_id[pip],
drm_device->crtc_id, buf->fb_id, 0,
/* dst_x, dst_y, dst_w, dst_h */
25, 25, drm_device->width/3, drm_device->height/3,
/* src_x, src_y, src_w, src_h*/
0, 0, v4l2_device->width << 16, v4l2_device->height << 16);
} else {
ret = drmModeSetPlane(drm_device->fd, drm_device->plane_id[pip],
drm_device->crtc_id, buf->fb_id, 0,
/* make video fullscreen: */
/* dst_x, dst_y, dst_w, dst_h */
0, 0, drm_device->width, drm_device->height,
/* src_x, src_y, src_w, src_h*/
0, 0 , v4l2_device->width << 16, v4l2_device->height << 16);
}

if (ret) {
ERROR("failed to enable plane %d: %s",
drm_device->plane_id[pip], strerror(errno));
}
"

I want also use three bufferes to do ping-pong circle in kmscube, but cause i am a newbee to gpu program, i dont know how to modify the code, in kmscube code on glsdk , there only use two bufferes do ping-pong circle, just like my project was done. I think add more buffer to play circle will reduce the tearing effect .
Do you know how to use three bufferes to do ping-pong circle in kmscube(GLSDK)?

Best regards
Sid