From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Kumar, Shobhit" Subject: Re: [PATCH] drm/i915: Fix crash when failing to parse MIPI VBT Date: Fri, 25 Jul 2014 15:11:17 +0530 Message-ID: <53D2263D.7080006@intel.com> References: <1406211372-25120-1-git-send-email-rafael.barbalho@intel.com> <20140725074706.GK4747@phenom.ffwll.local> <20140725075010.GL4747@phenom.ffwll.local> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Content-Transfer-Encoding: 7bit Return-path: Received: from mga03.intel.com (mga03.intel.com [143.182.124.21]) by gabe.freedesktop.org (Postfix) with ESMTP id 62B9F6E02A for ; Fri, 25 Jul 2014 02:41:20 -0700 (PDT) In-Reply-To: <20140725075010.GL4747@phenom.ffwll.local> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" To: Daniel Vetter , rafael.barbalho@intel.com Cc: intel-gfx@lists.freedesktop.org List-Id: intel-gfx@lists.freedesktop.org On 7/25/2014 1:20 PM, Daniel Vetter wrote: > On Fri, Jul 25, 2014 at 09:47:06AM +0200, Daniel Vetter wrote: >> On Thu, Jul 24, 2014 at 03:16:12PM +0100, rafael.barbalho@intel.com wrote: >>> From: Rafael Barbalho >>> >>> This particular nasty presented itself while trying to register the >>> intelfb device (intel_fbdev.c). During the process of registering the device >>> the driver will disable the crtc via i9xx_crtc_disable. These will >>> also disable the panel using the generic mipi panel functions in >>> dsi_mod_vbt_generic.c. The stale MIPI generic data sequence pointers would >>> cause a crash within those functions. However, all of this is happening >>> while console_lock is held from do_register_framebuffer inside fbcon.c. Which >>> means that you got kernel log and just the device appearing to reboot/hang for >>> no apparent reason. >> >> CONFIG_I915_FBDEV=n for when the console_lock gets in the way. >> >>> The fault started from the FB_EVENT_FB_REGISTERED event using the >>> fb_notifier_call_chain call in fbcon.c. >>> >>> Cc: Shobhit Kumar >>> Signed-off-by: Rafael Barbalho >> >> Queued for -next, thanks for the patch. > > Actually this is for fixes since 3.16 has dsi support. Also for > regressions please cite the commit that introduced the offending > behaviour. I've added that. Also this reminds me that there is still a WARN dump in 3.16 which will be fixed by - [v2] drm/i915: Add correct hw/sw config check for DSI encoder Assuming this can go in -fixes if it okay, this is waiting for review Regards Shobhit