From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Warren Subject: Re: [PATCH] drm: tegra: Use framebuffer pitch as line stride Date: Tue, 27 Nov 2012 14:39:30 -0700 Message-ID: <50B53312.7040000@wwwdotorg.org> References: <1353613037-15808-1-git-send-email-thierry.reding@avionic-design.de> <50B3EF29.6000308@wwwdotorg.org> <50B43096.4060302@nvidia.com> <50B503C5.6010208@wwwdotorg.org> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <50B503C5.6010208-3lzwWm7+Weoh9ZMKESR00Q@public.gmane.org> Sender: linux-tegra-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Mark Zhang Cc: Thierry Reding , Dave Airlie , "dri-devel-PD4FTy7X32lNgt0PjOBp9y5qC8QIuHrW@public.gmane.org" , "linux-tegra-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , Marc Dietrich , Jon Mayo List-Id: linux-tegra@vger.kernel.org On 11/27/2012 11:17 AM, Stephen Warren wrote: > On 11/26/2012 08:16 PM, Mark Zhang wrote: >> On 11/27/2012 06:37 AM, Stephen Warren wrote: >>> On 11/22/2012 12:37 PM, Thierry Reding wrote: >>>> Instead of using the stride derived from the display mode, use the pitch >>>> associated with the currently active framebuffer. This fixes a bug where >>>> the LCD display content would be skewed when enabling HDMI with a video >>>> mode different from that of the LCD. >>> >>> This patch certainly doesn't cause any additional issues for me, so: >>> >>> Tested-by: Stephen Warren >>> >>> Howwever, it still doesn't allow both Cardhu's LCD panel and external >>> HDMI port (1080p) to be active at once. If I boot with both enabled, or >>> boot with just the LCD enabled and hot-plug HDMI, as soon as both heads >>> are active, then some kind of display corruption starts; it looks like a >>> clocking issue or perhaps memory underflow. >> >> I haven't observed this issue. What kind of display corruption you mean? >> Did it recover after some seconds or the display in LVDS panel was >> always corrupted? >> >> During my testing, I connected HDMI while booting cardhu and I can see >> the LVDS and HDMI working with no corruptions. > > For your viewing pleasure (and playing with my new phone) :-) > http://www.youtube.com/watch?v=ZJxJnONz7DA > > The external monitor is 1920x1200 I believe. Jon Mayo says the corruption in the video is display (memory fetch) underflow. Perhaps this is because (IIRC) the BCT I'm using on Cardhu programs the memory controller at a slow rate, and the bootloader and/or kernel is supposed to bump up the rate to the max, but that's not implemented anywhere yet upstream. If you're testing with "fastboot" instead of U-Boot, that might be re-programming the memory frequencies, and hence avoiding this. I guess we have a fun time ahead of us with mode validation and memory controller programming.