Setting HDMI output frame rate is controlled by framebuffer

[840764397]

Hi,
I use Jetson-Xavier. Jetpack4.4-r32.4.3
Can I set the frame rate of HDMI output to be controlled by framebuffer? When the framebuffer is updated, let HDMI output the framebuffer. When the framebuffer is not updated, HDMI does not output data.
If it can be modified, how to modify it?

[WayneWWW]

Sorry that not quite understand what you are asking here… The frame rate is changed through the display kernel driver.

And the update of the monitor is through our SOR driver. These two follows the upper layer graphic driver to take their action.

[840764397]

Thank you for your reply.
We use /dev/fb0 memory mapped image file in the application and output it through HDMI interface.
The HDMI output is fixed at 30fps.
Can I set the frame rate of HDMI output to be controlled by /dev/fb0? When the framebuffer memory is updated, let HDMI output the framebuffer memory.
Can this be done?
Thank you very much.

[WayneWWW]

No, this node is not able to control the framerate.

You can set the frame rate from /sys/class/graphisc/fb0/mode. Something like that.

[840764397]

Thank you for your replay
cat /sys/class/graphics/fb0/modes

I want to add my own mode in /sys/class/graphics/fb0/modes. Can I add it? If yes, how to add it? Thank you very much.

[WayneWWW]

Cannot add. We only accept mode from edid.