svn commit: r227534 - releng/9.0/sys/dev/mfi

[Xin LI]

Author: delphij
Date: Tue Nov 15 17:42:00 2011
New Revision: 227534
URL: http://svn.freebsd.org/changeset/base/227534

Log:
  MFC r227409:
  
  Do a dummy read to flush the interrupt ACK that we just performed,
  ensuring that everything is really, truly consistent.
  
  This fixes certain cases where one will see various:
    mfi0: COMMAND 0xffffffXXXXXXXXXX TIMEOUT AFTER XX SECONDS
  
  Submitted by:	scottl
  Ok'ed by:	jhb
  Approved by:	re (kib)

Modified:
  releng/9.0/sys/dev/mfi/mfi.c
Directory Properties:
  releng/9.0/sys/   (props changed)

Modified: releng/9.0/sys/dev/mfi/mfi.c
==============================================================================
--- releng/9.0/sys/dev/mfi/mfi.c	Tue Nov 15 17:30:03 2011	(r227533)
+++ releng/9.0/sys/dev/mfi/mfi.c	Tue Nov 15 17:42:00 2011	(r227534)
@@ -932,6 +932,12 @@ mfi_intr(void *arg)
 	if (sc->mfi_check_clear_intr(sc))
 		return;
 
+	/*
+	 * Do a dummy read to flush the interrupt ACK that we just performed,
+	 * ensuring that everything is really, truly consistent.
+	 */
+	(void)sc->mfi_read_fw_status(sc);
+
 	pi = sc->mfi_comms->hw_pi;
 	ci = sc->mfi_comms->hw_ci;
 	mtx_lock(&sc->mfi_io_lock);