pcmcia: improve check for same card in slot after resume
Dominik Brodowski [Sat, 2 Jan 2010 13:14:23 +0000 (14:14 +0100)]
During a suspend/resume cycle, an user may change the card in the
PCMCIA/CardBus slot. The pcmcia_core can at least look at the
socket state to check whether it is the same.

For PCMCIA devices, move the detection and handling of such a
change to ds.c.

For CardBus devices, the PCI hotplug interface doesn't offer a "rescan"
facility which also _removes_ devices no longer to be found behind a
bridge. Therefore, remove and re-add all devices unconditionally.

CC: Jesse Barnes <jbarnes@virtuousgeek.org>
CC: Linus Torvalds <torvalds@linux-foundation.org>
Tested-by: Wolfram Sang <w.sang@pengutronix.de>
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>

drivers/pcmcia/cistpl.c
drivers/pcmcia/cs.c
drivers/pcmcia/ds.c
include/pcmcia/ss.h

index 04bf1ba..a8323cb 100644 (file)
@@ -377,6 +377,7 @@ int verify_cis_cache(struct pcmcia_socket *s)
        kfree(buf);
        return 0;
 }
+EXPORT_SYMBOL(verify_cis_cache);
 
 /*======================================================================
 
index 96d8d25..8c51493 100644 (file)
@@ -328,7 +328,7 @@ static int send_event(struct pcmcia_socket *s, event_t event, int priority)
 {
        int ret;
 
-       if (s->state & SOCKET_CARDBUS)
+       if ((s->state & SOCKET_CARDBUS) && (event != CS_EVENT_CARD_REMOVAL))
                return 0;
 
        dev_dbg(&s->dev, "send_event(event %d, pri %d, callback 0x%p)\n",
@@ -346,13 +346,6 @@ static int send_event(struct pcmcia_socket *s, event_t event, int priority)
        return ret;
 }
 
-static void socket_remove_drivers(struct pcmcia_socket *skt)
-{
-       dev_dbg(&skt->dev, "remove_drivers\n");
-
-       send_event(skt, CS_EVENT_CARD_REMOVAL, CS_EVENT_PRI_HIGH);
-}
-
 static int socket_reset(struct pcmcia_socket *skt)
 {
        int status, i;
@@ -395,7 +388,7 @@ static void socket_shutdown(struct pcmcia_socket *s)
 
        dev_dbg(&s->dev, "shutdown\n");
 
-       socket_remove_drivers(s);
+       send_event(s, CS_EVENT_CARD_REMOVAL, CS_EVENT_PRI_HIGH);
        s->state &= SOCKET_INUSE | SOCKET_PRESENT;
        msleep(shutdown_delay * 10);
        s->state &= SOCKET_INUSE;
@@ -462,7 +455,8 @@ static int socket_setup(struct pcmcia_socket *skt, int initial_delay)
                        return -EINVAL;
                }
                skt->state |= SOCKET_CARDBUS;
-       }
+       } else
+               skt->state &= ~SOCKET_CARDBUS;
 
        /*
         * Decode the card voltage requirements, and apply power to the card.
@@ -544,6 +538,8 @@ static int socket_suspend(struct pcmcia_socket *skt)
        if (skt->state & SOCKET_SUSPEND)
                return -EBUSY;
 
+       skt->suspended_state = skt->state;
+
        send_event(skt, CS_EVENT_PM_SUSPEND, CS_EVENT_PRI_LOW);
        skt->socket = dead_socket;
        skt->ops->set_socket(skt, &skt->socket);
@@ -566,38 +562,37 @@ static int socket_early_resume(struct pcmcia_socket *skt)
 
 static int socket_late_resume(struct pcmcia_socket *skt)
 {
-       if (!(skt->state & SOCKET_PRESENT)) {
-               skt->state &= ~SOCKET_SUSPEND;
+       skt->state &= ~SOCKET_SUSPEND;
+
+       if (!(skt->state & SOCKET_PRESENT))
                return socket_insert(skt);
+
+       if (skt->resume_status) {
+               socket_shutdown(skt);
+               return 0;
        }
 
-       if (skt->resume_status == 0) {
-               /*
-                * FIXME: need a better check here for cardbus cards.
-                */
-               if (verify_cis_cache(skt) != 0) {
-                       dev_dbg(&skt->dev, "cis mismatch - different card\n");
-                       socket_remove_drivers(skt);
-                       destroy_cis_cache(skt);
-                       kfree(skt->fake_cis);
-                       skt->fake_cis = NULL;
-                       /*
-                        * Workaround: give DS time to schedule removal.
-                        * Remove me once the 100ms delay is eliminated
-                        * in ds.c
-                        */
-                       msleep(200);
-                       send_event(skt, CS_EVENT_CARD_INSERTION, CS_EVENT_PRI_LOW);
-               } else {
-                       dev_dbg(&skt->dev, "cis matches cache\n");
-                       send_event(skt, CS_EVENT_PM_RESUME, CS_EVENT_PRI_LOW);
-               }
-       } else {
+       if (skt->suspended_state != skt->state) {
+               dev_dbg(&skt->dev,
+                       "suspend state 0x%x != resume state 0x%x\n",
+                       skt->suspended_state, skt->state);
+
                socket_shutdown(skt);
+               return socket_insert(skt);
        }
 
-       skt->state &= ~SOCKET_SUSPEND;
+#ifdef CONFIG_CARDBUS
+       if (skt->state & SOCKET_CARDBUS) {
+               /* We can't be sure the CardBus card is the same
+                * as the one previously inserted. Therefore, remove
+                * and re-add... */
+               cb_free(skt);
+               cb_alloc(skt);
+               return 0;
+       }
+#endif
 
+       send_event(skt, CS_EVENT_PM_RESUME, CS_EVENT_PRI_LOW);
        return 0;
 }
 
index defa44c..87e0639 100644 (file)
@@ -1252,8 +1252,22 @@ static int ds_event(struct pcmcia_socket *skt, event_t event, int priority)
        case CS_EVENT_EJECTION_REQUEST:
                break;
 
-       case CS_EVENT_PM_SUSPEND:
        case CS_EVENT_PM_RESUME:
+               if (verify_cis_cache(skt) != 0) {
+                       dev_dbg(&skt->dev, "cis mismatch - different card\n");
+                       /* first, remove the card */
+                       ds_event(skt, CS_EVENT_CARD_REMOVAL, CS_EVENT_PRI_HIGH);
+                       destroy_cis_cache(skt);
+                       kfree(skt->fake_cis);
+                       skt->fake_cis = NULL;
+                       /* now, add the new card */
+                       ds_event(skt, CS_EVENT_CARD_INSERTION,
+                                CS_EVENT_PRI_LOW);
+               }
+               handle_event(skt, event);
+               break;
+
+       case CS_EVENT_PM_SUSPEND:
        case CS_EVENT_RESET_PHYSICAL:
        case CS_EVENT_CARD_RESET:
        default:
index cbfba88..b0ebd11 100644 (file)
@@ -137,6 +137,7 @@ struct pcmcia_socket {
        spinlock_t                      lock;
        socket_state_t                  socket;
        u_int                           state;
+       u_int                           suspended_state;        /* state before suspend */
        u_short                         functions;
        u_short                         lock_count;
        pccard_mem_map                  cis_mem;