[src/trunk]: src/sys/dev/pci Add WM_F_WA_I210_CLSEM flag for a workaround. Fr...

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

details:   https://anonhg.NetBSD.org/src/rev/88567f3ecaf5
branches:  trunk
changeset: 825654:88567f3ecaf5
user:      msaitoh <msaitoh%NetBSD.org@localhost>
date:      Thu Jul 27 03:21:42 2017 +0000

description:
Add WM_F_WA_I210_CLSEM flag for a workaround. FreeBSD/Linux drivers say
"In rare circumstances, the SW semaphore may already be held unintentionally."
on I21[01]. PXE boot is one of the case.

XXX pullup-[678].

diffstat:

 sys/dev/pci/if_wm.c    |  17 +++++++++++++++--
 sys/dev/pci/if_wmvar.h |   3 ++-
 2 files changed, 17 insertions(+), 3 deletions(-)

diffs (69 lines):

diff -r 97fc2ff0e85f -r 88567f3ecaf5 sys/dev/pci/if_wm.c
--- a/sys/dev/pci/if_wm.c       Thu Jul 27 02:11:24 2017 +0000
+++ b/sys/dev/pci/if_wm.c       Thu Jul 27 03:21:42 2017 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: if_wm.c,v 1.532 2017/07/26 08:09:59 msaitoh Exp $      */
+/*     $NetBSD: if_wm.c,v 1.533 2017/07/27 03:21:42 msaitoh Exp $      */
 
 /*
  * Copyright (c) 2001, 2002, 2003, 2004 Wasabi Systems, Inc.
@@ -83,7 +83,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: if_wm.c,v 1.532 2017/07/26 08:09:59 msaitoh Exp $");
+__KERNEL_RCSID(0, "$NetBSD: if_wm.c,v 1.533 2017/07/27 03:21:42 msaitoh Exp $");
 
 #ifdef _KERNEL_OPT
 #include "opt_net_mpsafe.h"
@@ -2215,6 +2215,8 @@
                break;
        case WM_T_I210:
        case WM_T_I211:
+               /* Allow a single clear of the SW semaphore on I210 and newer*/
+               sc->sc_flags |= WM_F_WA_I210_CLSEM;
                if (wm_nvm_get_flash_presence_i210(sc)) {
                        sc->nvm.read = wm_nvm_read_eerd;
                        /* Don't use WM_F_LOCK_EECD because we use EERD */
@@ -12704,6 +12706,7 @@
                device_xname(sc->sc_dev), __func__));
        KASSERT(sc->sc_nvm_wordsize > 0);
 
+retry:
        /* Get the SW semaphore. */
        timeout = sc->sc_nvm_wordsize + 1;
        while (timeout) {
@@ -12717,6 +12720,16 @@
        }
 
        if (timeout == 0) {
+               if ((sc->sc_flags & WM_F_WA_I210_CLSEM) != 0) {
+                       /*
+                        * In rare circumstances, the SW semaphore may already
+                        * be held unintentionally. Clear the semaphore once
+                        * before giving up.
+                        */
+                       sc->sc_flags &= ~WM_F_WA_I210_CLSEM;
+                       wm_put_swsm_semaphore(sc);
+                       goto retry;
+               }
                aprint_error_dev(sc->sc_dev,
                    "could not acquire SWSM SMBI\n");
                return 1;
diff -r 97fc2ff0e85f -r 88567f3ecaf5 sys/dev/pci/if_wmvar.h
--- a/sys/dev/pci/if_wmvar.h    Thu Jul 27 02:11:24 2017 +0000
+++ b/sys/dev/pci/if_wmvar.h    Thu Jul 27 03:21:42 2017 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: if_wmvar.h,v 1.36 2017/07/26 06:48:49 msaitoh Exp $    */
+/*     $NetBSD: if_wmvar.h,v 1.37 2017/07/27 03:21:42 msaitoh Exp $    */
 
 /*
  * Copyright (c) 2001, 2002, 2003, 2004 Wasabi Systems, Inc.
@@ -96,6 +96,7 @@
 #define WM_F_80003_MDIC_WA     0x01000000 /* 80003 MDIC workaround */
 #define        WM_F_PCS_DIS_AUTONEGO   0x02000000 /* PCS Disable Autonego */
 #define        WM_F_PLL_WA_I210        0x04000000 /* I21[01] PLL workaround */
+#define        WM_F_WA_I210_CLSEM      0x08000000 /* I21[01] Semaphore workaround */
 
 #define WM_FLAGS "\20" \
        "\1" "HAS_MII"  "\2" "LOCK_EECD" "\3" "_B02"    "\4" "_B03"     \