Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1422698AbbEOBJC (ORCPT ); Thu, 14 May 2015 21:09:02 -0400 Received: from mail-vn0-f42.google.com ([209.85.216.42]:46635 "EHLO mail-vn0-f42.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933661AbbEOBI5 (ORCPT ); Thu, 14 May 2015 21:08:57 -0400 MIME-Version: 1.0 In-Reply-To: References: <1431618016-2087-1-git-send-email-javier.martinez@collabora.co.uk> <1431618016-2087-8-git-send-email-javier.martinez@collabora.co.uk> Date: Fri, 15 May 2015 10:08:56 +0900 X-Google-Sender-Auth: klax6aoBsbDxTV1XvTTeQBOrm3E Message-ID: Subject: Re: [PATCH 7/9] ARM: multi_v7_defconfig: Enable options for Exynos display support From: Krzysztof Kozlowski To: Javier Martinez Canillas Cc: Krzysztof Kozlowski , Javier Martinez Canillas , arm@kernel.org, Arnd Bergmann , Olof Johansson , Kevin Hilman , Doug Anderson , Kukjin Kim , "linux-samsung-soc@vger.kernel.org" , Linux Kernel Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2964 Lines: 71 2015-05-15 9:58 GMT+09:00 Javier Martinez Canillas : > Hello Krzysztof, > > On Fri, May 15, 2015 at 2:36 AM, Krzysztof Kozlowski > wrote: >> 2015-05-15 0:40 GMT+09:00 Javier Martinez Canillas >> : >>> Many Exynos devices have devices attached to their display ports. >>> This patch enables the needed Kconfig options to support different >>> configuration such as simple panel, embedded DisplayPort (eDP) to >>> LVDS bridges and HDMI displays. >> >> Enabling the display would be nice but for some quite long time we had >> issues with DRM on Exynos. exynos_defconfig has it enabled and most of >> boards boot fine with it. Exception is Arndale 5250: > > Yes, like I said in the other thread, the fact that Exynos DRM is > working fine now on most boards is mostly because the bugs were > exposed when the Exynos DRM options were enabled. I saw your response in email 0/9 but let us stick to one thread. So these are my only concerns - instability in the past. >> http://storage.kernelci.org/next/next-20150514/arm-exynos_defconfig/lab-khilman/boot-exynos5250-arndale.html >> [ 1.630290] [drm:exynos_dp_bind] *ERROR* failed: of_get_videomode() : -22 >> [ 1.637071] exynos-drm exynos-drm: failed to bind >> 145b0000.dp-controller (ops exynos_dp_ops): -22 >> [ 1.646504] exynos-drm exynos-drm: master bind failed: -22 >> [ 1.651391] exynos-drm: probe of exynos-drm failed with error -22 >> > > Ajay Kumar changed the DT bindings for the Exynos DRM Display Panel > driver some time ago but it seems that the Arndale 5250 DTS was never > updated. Something along the lines of commit [0] is needed. Thanks, > >> Anyway it is not like I am against it... just wondering. On the other >> hand enabling it could help in early detection of errors. >> > > I think that not enabling these options will just make latent bugs to > not be exposed. As an example I found that module auto-loading was > broken for the driver of the PTN3460 eDP to LVDS bridge used in the > Exynos5250 Snow Chromebook and already posted a fix [1]. Right, enabling the options helps in exposing problems so they could be spotted and fixed. > I would had never found that bug if wouldn't had tried enabling these > options in multi_v7 as a module. Also remember that the consumer > version of these machines don't have a serial console so for users > building images with multi_v7, not having display support means that > the machine is pretty useless. That is indeed good reason. FWIW, I tested multi_v7 with your patches on Exynos4412 Trats2 board and it worked fine. Reviewed-by: Krzysztof Kozlowski Best regards, Krzysztof -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/