svn commit: r292409 - head/sys/dev/drm2/i915

[John Baldwin]

Author: jhb
Date: Thu Dec 17 20:33:20 2015
New Revision: 292409
URL: https://svnweb.freebsd.org/changeset/base/292409

Log:
  t seems certain Intel GPUs use GPIO bitbanging over a child device
  instead of GMBUS access for I2C transfers.  The GMBUS driver falls back
  to this mode when a transfer times out.  However, the first transfer to
  timeout was sending the request back to itself resulting in an panic due
  to recursing on a lock.  Fix it to forward the request on to the proper
  device.  This appears to have been accidentally changed in r277487.
  
  Reported by:	Joe Maloney <jmaloney at pcbsd.org>
  Reviewed by:	adrian, dumbbell, imp
  MFC after:	1 week
  Differential Revision:	https://reviews.freebsd.org/D4599

Modified:
  head/sys/dev/drm2/i915/intel_iic.c

Modified: head/sys/dev/drm2/i915/intel_iic.c
==============================================================================
--- head/sys/dev/drm2/i915/intel_iic.c	Thu Dec 17 19:36:25 2015	(r292408)
+++ head/sys/dev/drm2/i915/intel_iic.c	Thu Dec 17 20:33:20 2015	(r292409)
@@ -456,7 +456,7 @@ timeout:
 
 	/* Hardware may not support GMBUS over these pins? Try GPIO bitbanging instead. */
 	sc->force_bit_dev = true;
-	error = -IICBUS_TRANSFER(adapter, msgs, num);
+	error = -IICBUS_TRANSFER(dev_priv->bbbus[unit], msgs, num);
 
 out:
 	sx_xunlock(&dev_priv->gmbus_sx);