SGX 3.01.00.02 SDK Linuxfbwsegl issue/question

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1

I am running the latest opengl sdk (3.01.00.02) with the console-
image. I have set the framebuffer for triple buffering:

fbset -fb /dev/fb0 -xres 800 -yres 480 -vxres 800 -vyres 1440

I have also set up 800x480MR-16@60 in uboot.

I have set the window system to libpvrPVR2D_LINUXFBWSEGL, which
appears to produce the best picture but when running some demos i
still see what appears to be a horizontal hsync tearing issue across
the middle of the screen. The problem goes away when the demo is
paused. The coverflow demo is a good example of this.

The problem is also present for 640x480 resolution. Is this an issue
anyone else has seen? Anyone know what libpvrPVR2D_LINUXFBWSEGL does?
The documentation only states that it may give better performance than
FLIP which it does as FLIP causes a stuttering problem for me.

Thanks,

Paul

2

I am running the latest opengl sdk (3.01.00.02) with the console-
image. I have set the framebuffer for triple buffering:

fbset -fb /dev/fb0 -xres 800 -yres 480 -vxres 800 -vyres 1440

I have also set up 800x480MR-16@60 in uboot.

I have set the window system to libpvrPVR2D_LINUXFBWSEGL, which
appears to produce the best picture but when running some demos i
still see what appears to be a horizontal hsync tearing issue across
the middle of the screen. The problem goes away when the demo is
paused. The coverflow demo is a good example of this.

The problem is also present for 640x480 resolution. Is this an issue
anyone else has seen? Anyone know what libpvrPVR2D_LINUXFBWSEGL does?
The documentation only states that it may give better performance than
FLIP which it does as FLIP causes a stuttering problem for me.

Did you try FLIP with triple buffering?
http://tiexpressdsp.com/index.php/GSG:_AM35x_and_OMAP35x_Graphics_SDK_Additional_Procedures#Switching_between_FrontEGL_and_FlipEGL_Modes

regards,
Amit Pundir

3

I tried the FLIP driver and it is not as smooth as the LINUXFB driver.
I'm not sure why this is, but it looks as though there is a framerate
difference. I'd really like to understand why this is.
The OGLES2Coverflow demo has a problem with FLIP also, so maybe there
is a problem with this demo. You still get slight tearing so maybe
this demo does not work well with FLIP and LINUXFB. I have not looked
at the demo source code yet to see what it is doing though.
I did look at the steps in the link and this is what i am doing (i
tried the 640x480 resolution).

BTW - I've tried the development 2.6.29 and 2.6.31 kernel builds in OE
and both show the same problem. I've not tried the stable branch with
this SDK yet though.

Paul