| From | Greg Kroah-Hartman <> | Subject | [PATCH 3.16 024/357] drm/i915: Fix crash when failing to parse MIPI VBT | Date | Fri, 3 Oct 2014 14:26:50 -0700 |
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3.16-stable review patch. If anyone has any objections, please let me know.
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From: Rafael Barbalho <rafael.barbalho@intel.com>
commit ed3b6679936801fa2dab47e7a6ef74e383400ed9 upstream.
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 <shobhit.kumar@intel.com> Date: Mon Apr 14 11:00:34 2014 +0530
drm/i915: Add parsing support for new MIPI blocks in VBT
Cc: Shobhit Kumar <shobhit.kumar@intel.com> Signed-off-by: Rafael Barbalho <rafael.barbalho@intel.com> Reviewed-by: Shobhit Kumar <shobhit.kumar@intel.com> [danvet: Add regression citation.] Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- drivers/gpu/drm/i915/intel_bios.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/drivers/gpu/drm/i915/intel_bios.c +++ b/drivers/gpu/drm/i915/intel_bios.c @@ -877,7 +877,7 @@ 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,
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