On 7/24/2014 7:46 PM, rafael.barbalho@xxxxxxxxx wrote:
From: Rafael Barbalho <rafael.barbalho@xxxxxxxxx> 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. Cc: Shobhit Kumar <shobhit.kumar@xxxxxxxxx> Signed-off-by: Rafael Barbalho <rafael.barbalho@xxxxxxxxx> --- 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));
Ouch !! This mistake hurts. This is manifesting now because the VBT probably you tested had sequences not supported by the driver. I am influencing a TLV based VBT structure design for the sequence which when done will ensure proper parsing for all that is known and unknown pointers will remain NULL. But for now
Reviewed-by: Shobhit Kumar <shobhit.kumar@xxxxxxxxx> Regards Shobhit _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/intel-gfx
