Re: mx6 hdmi resolution behaviour

On Tue, Jun 23, 2015 at 5:58 PM, Russell King - ARM Linux linux@arm.linux.org.uk wrote:

...

That's the point that makes me confused: shouldn't it report a higher resolution like 1080p?

No - it won't go higher than the initial mode that was set. See drm_fb_helper_hotplug_event():

    max_width = fb_helper->fb->width;
    max_height = fb_helper->fb->height;

    drm_fb_helper_probe_connector_modes(fb_helper, max_width, max_height);

This calls connector->funcs->fill_modes with the max width/height, which calls down into drm_helper_probe_single_connector_modes_merge_bits() and there's limitations in there which means that we won't try to increase the size of the framebuffer.

Got it, thanks for the clarification, Russell.