From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mark Zhang Subject: Re: Tegra DRM with HDMI support (\o/) Date: Thu, 18 Oct 2012 14:04:37 +0800 Message-ID: <507F9BF5.20002@nvidia.com> References: <20121011200705.GB27599@avionic-0098.mockup.avionic-design.de> <1350375538.2332.31.camel@markz-hp6200> <507D856C.1070708@wwwdotorg.org> <20121017054224.GA21783@avionic-0098.mockup.avionic-design.de> Mime-Version: 1.0 Content-Type: text/plain; charset="ISO-8859-1"; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20121017054224.GA21783-RM9K5IK7kjIQXX3q8xo1gnVAuStQJXxyR5q1nwbD4aMs9pC9oP6+/A@public.gmane.org> Sender: linux-tegra-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Thierry Reding Cc: Stephen Warren , "linux-tegra-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" List-Id: linux-tegra@vger.kernel.org On 10/17/2012 01:42 PM, Thierry Reding wrote: > * PGP Signed by an unknown key > > On Tue, Oct 16, 2012 at 10:03:56AM -0600, Stephen Warren wrote: >> On 10/16/2012 02:18 AM, Mark Zhang wrote: >>> Hi, >>> >>> I've made this drm driver worked on Tegra 3(LVDS and HDMI both). >>> But the code that Thierry >>> hosts(git://gitorious.org/thierryreding/linux.git) doesn't work >>> directly. If you build and run it, you'll get a white blank screen on >>> Tegra 3. I didn't find the root cause but I think this is not caused by >>> drm driver itself(maybe the PCIE codes?). The main symptom is: some >>> regulators can't be inited all the time. I tried to build drm driver as >>> kernel module, after kernel booted, modprobe the drm driver, and you'll >>> find there are a lot of error prints like this: >>> >>> ========================================================= >>> [ 21.383529] reg-fixed-voltage 1.regulator: Failed to find supply vin >>> [ 21.390299] reg-fixed-voltage 1.regulator: Failed to register >>> regulator: -517 >>> [ 21.397645] platform 1.regulator: Driver reg-fixed-voltage requests >>> probe deferral >>> [ 21.405604] platform 2.regulator: Driver reg-fixed-voltage requests >>> probe deferral >>> ========================================================= >> >> This is normal; it's probe deferral. You'll find that those regulators >> initialize correctly later. Hopefully tegra-drm handles this correctly, >> and passes that error code through as the result of its probe. > > I presume those regulators are for the vdd and pll supplies of the HDMI > output? Those should be properly handled by the tegra_hdmi_probe() > function. Also the way tegra-drm works right now, unless all of the > outputs are registered properly the DRM portion will never even be > initialized. > Not exactly. In hdmi driver, if I try to get/enable vdd & pll regulators which HDMI needs, error occurs. So currently to make HDMI working on Tegra 3, we need to temporarily remove these codes. In fact, there are a lot of this kind of errors, I just pasted some of them. So there is something in your changes which blocks these regulators correctly inited cause this issue doesn't exist in upstream codes. > Thierry > > * Unknown Key > * 0x7F3EB3A1 >