Display rotation

I saw in io-graphics documentatio that it is possible to rotate to 90 or 270 degrees the displays. This is suitable for me because I want to use an LCD display in portrait mode. The command is :

io-graphics -d “driver_name” hook=devg-rotate90.so xres=480,yres=640,bitpp=16 …

The documentation avdises that " You need to modify the X and Y resolution passed to io-graphics using the xres and yres options".

I made a test with a coral graphic card which runs correclty in 640x480, but it does not work in 480x640.

I made the same test with my own LCD driver which runs correctly in 320x240 but not in 240x320 with the hook=devg-rotate90.so option.

So I modified my LCD driver to manage 240x320 mode so it runs correctly (in portrait mode) but not with the hook=devg-rotate90.so option. With this option, I see 0 “Attached /dev/io-graphics/32FX00, id = 0” with sloginfo command but nothing is displayed and driver does nothing.

Is there anyone who experienced a correct result with devg-rotate90.so ?

What the interest of this option if it implies that the driver must manage the portrait mode itself ?

Is it a mistake on my side or a QNX bug ?

Thanks !!!