From ed3b6679936801fa2dab47e7a6ef74e383400ed9 Mon Sep 17 00:00:00 2001 From: Rafael Barbalho Date: Thu, 24 Jul 2014 15:16:12 +0100 Subject: [PATCH] drm/i915: Fix crash when failing to parse MIPI VBT 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. The fault started from the FB_EVENT_FB_REGISTERED event using the fb_notifier_call_chain call in fbcon.c. This regression has been introduced in commit d3b542fcfc72d7724585e3fd2c5e75351bc3df47 Author: Shobhit Kumar Date: Mon Apr 14 11:00:34 2014 +0530 drm/i915: Add parsing support for new MIPI blocks in VBT Cc: Shobhit Kumar Signed-off-by: Rafael Barbalho Reviewed-by: Shobhit Kumar [danvet: Add regression citation.] Cc: stable@vger.kernel.org Signed-off-by: Daniel Vetter --- 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, -- 2.7.4