[src/trunk]: src/sys/dev/pci Add comment to ICH/PCH's lock stuff in wm_reset().

[msaitoh <msaitoh%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/53c1fb46ac31
branches:  trunk
changeset: 372036:53c1fb46ac31
user:      msaitoh <msaitoh%NetBSD.org@localhost>
date:      Wed Oct 26 06:36:39 2022 +0000

description:
Add comment to ICH/PCH's lock stuff in wm_reset().

diffstat:

 sys/dev/pci/if_wm.c |  9 +++++++--
 1 files changed, 7 insertions(+), 2 deletions(-)

diffs (30 lines):

diff -r b677b2ea501f -r 53c1fb46ac31 sys/dev/pci/if_wm.c
--- a/sys/dev/pci/if_wm.c       Tue Oct 25 23:39:13 2022 +0000
+++ b/sys/dev/pci/if_wm.c       Wed Oct 26 06:36:39 2022 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: if_wm.c,v 1.765 2022/10/19 06:37:25 msaitoh Exp $      */
+/*     $NetBSD: if_wm.c,v 1.766 2022/10/26 06:36:39 msaitoh Exp $      */
 
 /*
  * Copyright (c) 2001, 2002, 2003, 2004 Wasabi Systems, Inc.
@@ -82,7 +82,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: if_wm.c,v 1.765 2022/10/19 06:37:25 msaitoh Exp $");
+__KERNEL_RCSID(0, "$NetBSD: if_wm.c,v 1.766 2022/10/26 06:36:39 msaitoh Exp $");
 
 #ifdef _KERNEL_OPT
 #include "opt_if_wm.h"
@@ -5579,6 +5579,11 @@
                CSR_WRITE(sc, WMREG_CTRL, reg);
                /* Don't insert a completion barrier when reset */
                delay(20*1000);
+               /*
+                * The EXTCNFCTR_MDIO_SW_OWNERSHIP bit is cleared by the reset,
+                * so don't use sc->phy.release(sc). Release sc_ich_phymtx
+                * only. See also wm_get_swflag_ich8lan().
+                */
                mutex_exit(sc->sc_ich_phymtx);
                break;
        case WM_T_82580: