[src/trunk]: src/sys/dev/sdmmc We can't block our interrupt while sdmmc_detac...

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

details:   https://anonhg.NetBSD.org/src/rev/b32dfe0fd7c6
branches:  trunk
changeset: 783457:b32dfe0fd7c6
user:      jakllsch <jakllsch%NetBSD.org@localhost>
date:      Sat Dec 22 21:24:49 2012 +0000

description:
We can't block our interrupt while sdmmc_detach_card is called, as
it can issue commands, and some host drivers have interrupt-driven
command completion.  Prevents assertion (or deadlock) upon detach
of sdhc(4) with inserted card.

diffstat:

 sys/dev/sdmmc/sdmmc.c |  13 ++++++++++---
 1 files changed, 10 insertions(+), 3 deletions(-)

diffs (35 lines):

diff -r 98e5d32bfb36 -r b32dfe0fd7c6 sys/dev/sdmmc/sdmmc.c
--- a/sys/dev/sdmmc/sdmmc.c     Sat Dec 22 20:21:09 2012 +0000
+++ b/sys/dev/sdmmc/sdmmc.c     Sat Dec 22 21:24:49 2012 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: sdmmc.c,v 1.19 2012/12/22 20:21:09 jakllsch Exp $      */
+/*     $NetBSD: sdmmc.c,v 1.20 2012/12/22 21:24:49 jakllsch Exp $      */
 /*     $OpenBSD: sdmmc.c,v 1.18 2009/01/09 10:58:38 jsg Exp $  */
 
 /*
@@ -49,7 +49,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: sdmmc.c,v 1.19 2012/12/22 20:21:09 jakllsch Exp $");
+__KERNEL_RCSID(0, "$NetBSD: sdmmc.c,v 1.20 2012/12/22 21:24:49 jakllsch Exp $");
 
 #ifdef _KERNEL_OPT
 #include "opt_sdmmc.h"
@@ -271,8 +271,15 @@
        }
        /* time to die. */
        sc->sc_dying = 0;
-       if (ISSET(sc->sc_flags, SMF_CARD_PRESENT))
+       if (ISSET(sc->sc_flags, SMF_CARD_PRESENT)) {
+               /*
+                * sdmmc_card_detach() may issue commands,
+                * so temporarily drop the interrupt-blocking lock.
+                */
+               mutex_exit(&sc->sc_tskq_mtx);
                sdmmc_card_detach(sc, DETACH_FORCE);
+               mutex_enter(&sc->sc_tskq_mtx);
+       }
        sc->sc_tskq_lwp = NULL;
        cv_broadcast(&sc->sc_tskq_cv);
        mutex_exit(&sc->sc_tskq_mtx);