pcmcia: improve check for same card in slot after resume

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>

4 files changed, 47 insertions, 36 deletions

diff --git a/drivers/pcmcia/cistpl.c b/drivers/pcmcia/cistpl.c
index 04bf1ba607f7..a8323cb2e34d 100644
--- a/drivers/pcmcia/cistpl.c
+++ b/drivers/pcmcia/cistpl.c
@@ -377,6 +377,7 @@ int verify_cis_cache(struct pcmcia_socket *s)
         kfree(buf);
         return 0;
 }
+EXPORT_SYMBOL(verify_cis_cache);
 
 /*======================================================================
 
diff --git a/drivers/pcmcia/cs.c b/drivers/pcmcia/cs.c
index 96d8d25c209d..8c51493d1f95 100644
--- a/drivers/pcmcia/cs.c
+++ b/drivers/pcmcia/cs.c
@@ -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;
 }
 
diff --git a/drivers/pcmcia/ds.c b/drivers/pcmcia/ds.c
index defa44c27b97..87e06395c129 100644
--- a/drivers/pcmcia/ds.c
+++ b/drivers/pcmcia/ds.c
@@ -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:
diff --git a/include/pcmcia/ss.h b/include/pcmcia/ss.h
index cbfba885eb85..b0ebd11130cc 100644
--- a/include/pcmcia/ss.h
+++ b/include/pcmcia/ss.h
@@ -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;