[src/trunk]: src/sys/dev/sdmmc protect card detection with mutex.

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

details:   https://anonhg.NetBSD.org/src/rev/63bed603e857
branches:  trunk
changeset: 339778:63bed603e857
user:      mlelstv <mlelstv%NetBSD.org@localhost>
date:      Sun Aug 09 13:14:11 2015 +0000

description:
protect card detection with mutex.

diffstat:

 sys/dev/sdmmc/sdmmc.c |  44 ++++++++++++++++++++++++--------------------
 1 files changed, 24 insertions(+), 20 deletions(-)

diffs (81 lines):

diff -r 0de63a66a3ec -r 63bed603e857 sys/dev/sdmmc/sdmmc.c
--- a/sys/dev/sdmmc/sdmmc.c     Sun Aug 09 13:07:47 2015 +0000
+++ b/sys/dev/sdmmc/sdmmc.c     Sun Aug 09 13:14:11 2015 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: sdmmc.c,v 1.29 2015/08/03 10:08:51 jmcneill Exp $      */
+/*     $NetBSD: sdmmc.c,v 1.30 2015/08/09 13:14:11 mlelstv 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 1.29 2015/08/03 10:08:51 jmcneill Exp $");
+__KERNEL_RCSID(0, "$NetBSD: sdmmc.c,v 1.30 2015/08/09 13:14:11 mlelstv Exp $");
 
 #ifdef _KERNEL_OPT
 #include "opt_sdmmc.h"
@@ -315,19 +315,28 @@
 sdmmc_discover_task(void *arg)
 {
        struct sdmmc_softc *sc = (struct sdmmc_softc *)arg;
+       int card_detect, card_present;
 
-       if (sdmmc_chip_card_detect(sc->sc_sct, sc->sc_sch)) {
-               if (!ISSET(sc->sc_flags, SMF_CARD_PRESENT)) {
-                       SET(sc->sc_flags, SMF_CARD_PRESENT);
+       mutex_enter(&sc->sc_discover_task_mtx);
+       card_detect = sdmmc_chip_card_detect(sc->sc_sct, sc->sc_sch);
+       card_present = ISSET(sc->sc_flags, SMF_CARD_PRESENT);
+       if (card_detect)
+               SET(sc->sc_flags, SMF_CARD_PRESENT);
+       else
+               CLR(sc->sc_flags, SMF_CARD_PRESENT);
+       mutex_exit(&sc->sc_discover_task_mtx);
+
+       if (card_detect) {
+               if (!card_present) {
                        sdmmc_card_attach(sc);
+                       mutex_enter(&sc->sc_discover_task_mtx);
                        if (!ISSET(sc->sc_flags, SMF_CARD_ATTACHED))
                                CLR(sc->sc_flags, SMF_CARD_PRESENT);
+                       mutex_exit(&sc->sc_discover_task_mtx);
                }
        } else {
-               if (ISSET(sc->sc_flags, SMF_CARD_PRESENT)) {
-                       CLR(sc->sc_flags, SMF_CARD_PRESENT);
+               if (card_present)
                        sdmmc_card_detach(sc, DETACH_FORCE);
-               }
        }
 }
 
@@ -335,20 +344,15 @@
 sdmmc_polling_card(void *arg)
 {
        struct sdmmc_softc *sc = (struct sdmmc_softc *)arg;
-       int card_detect;
+       int card_detect, card_present;
 
-       mutex_enter(&sc->sc_mtx);
+       mutex_enter(&sc->sc_discover_task_mtx);
        card_detect = sdmmc_chip_card_detect(sc->sc_sct, sc->sc_sch);
-       if (card_detect) {
-               if (!ISSET(sc->sc_flags, SMF_CARD_PRESENT)) {
-                       sdmmc_needs_discover(sc->sc_dev);
-               }
-       } else {
-               if (ISSET(sc->sc_flags, SMF_CARD_PRESENT)) {
-                       sdmmc_needs_discover(sc->sc_dev);
-               }
-       }
-       mutex_exit(&sc->sc_mtx);
+       card_present = ISSET(sc->sc_flags, SMF_CARD_PRESENT);
+       mutex_exit(&sc->sc_discover_task_mtx);
+
+       if (card_detect != card_present)
+               sdmmc_needs_discover(sc->sc_dev);
 
        callout_schedule(&sc->sc_card_detect_ch, hz);
 }