From mboxrd@z Thu Jan 1 00:00:00 1970 From: linux@arm.linux.org.uk (Russell King - ARM Linux) Date: Tue, 23 Jun 2015 21:58:37 +0100 Subject: mx6 hdmi resolution behaviour In-Reply-To: References: <20150623164443.GC7557@n2100.arm.linux.org.uk> <20150623204154.GD7557@n2100.arm.linux.org.uk> Message-ID: <20150623205837.GE7557@n2100.arm.linux.org.uk> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Tue, Jun 23, 2015 at 05:48:51PM -0300, Fabio Estevam wrote: > On Tue, Jun 23, 2015 at 5:41 PM, Russell King - ARM Linux > wrote: > > > I've just tried this (the HBi1 was booted previously with the HDMI socket > > disconnected). Just now, I turned the TV on, and then connected it to > > the HDMI. > > Thanks for testing it. > > > The TV reported a resolution of 1024x768, and the kernel log was silent. > > 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. You do get that behaviour if you have the X server running, and that's all down to the X server itself doing that (reacting to the hotplug event which DRM generates.) -- FTTC broadband for 0.8mile line: currently at 10.5Mbps down 400kbps up according to speedtest.net.