From mboxrd@z Thu Jan 1 00:00:00 1970 From: Daniel Vetter Subject: Re: [PATCH] drm/i915: Fix crash when failing to parse MIPI VBT Date: Fri, 25 Jul 2014 09:50:10 +0200 Message-ID: <20140725075010.GL4747@phenom.ffwll.local> References: <1406211372-25120-1-git-send-email-rafael.barbalho@intel.com> <20140725074706.GK4747@phenom.ffwll.local> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from mail-wg0-f41.google.com (mail-wg0-f41.google.com [74.125.82.41]) by gabe.freedesktop.org (Postfix) with ESMTP id 54E496E7E2 for ; Fri, 25 Jul 2014 00:50:01 -0700 (PDT) Received: by mail-wg0-f41.google.com with SMTP id z12so3901023wgg.24 for ; Fri, 25 Jul 2014 00:50:00 -0700 (PDT) Content-Disposition: inline In-Reply-To: <20140725074706.GK4747@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: rafael.barbalho@intel.com Cc: intel-gfx@lists.freedesktop.org List-Id: intel-gfx@lists.freedesktop.org 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. -Daniel > -Daniel > > --- > > drivers/gpu/drm/i915/intel_bios.c | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > diff --git a/drivers/gpu/drm/i915/intel_bios.c b/drivers/gpu/drm/i915/intel_bios.c > > index 608ed30..a669550 100644 > > --- a/drivers/gpu/drm/i915/intel_bios.c > > +++ b/drivers/gpu/drm/i915/intel_bios.c > > @@ -878,7 +878,7 @@ err: > > > > /* error during parsing so set all pointers to null > > * because of partial parsing */ > > - memset(dev_priv->vbt.dsi.sequence, 0, MIPI_SEQ_MAX); > > + memset(dev_priv->vbt.dsi.sequence, 0, sizeof(dev_priv->vbt.dsi.sequence)); > > } > > > > static void parse_ddi_port(struct drm_i915_private *dev_priv, enum port port, > > -- > > 2.0.2 > > > > _______________________________________________ > > Intel-gfx mailing list > > Intel-gfx@lists.freedesktop.org > > http://lists.freedesktop.org/mailman/listinfo/intel-gfx > > -- > Daniel Vetter > Software Engineer, Intel Corporation > +41 (0) 79 365 57 48 - http://blog.ffwll.ch -- Daniel Vetter Software Engineer, Intel Corporation +41 (0) 79 365 57 48 - http://blog.ffwll.ch