[PCMCIA] Add work-around for bouncy card detect signals.

Add work-around for i82365-based socket drivers to the core PCMCIA
code.  Since insert processing is not a time critical event, we can
afford to delay (by sleeping) these for everyone.

diff --git a/drivers/pcmcia/cs.c b/drivers/pcmcia/cs.c
index 14352eaa04053c644e402408719af75d482f55d0..6e94e86be1bffd5134844b19a4a06f71014aa461 100644 (file)
--- a/drivers/pcmcia/cs.c
+++ b/drivers/pcmcia/cs.c
@@ -794,6 +794,37 @@ static void socket_remove(struct pcmcia_socket *skt)
        module_put(skt->owner);
 }
 
+/*
+ * Process a socket card detect status change.
+ *
+ * If we don't have a card already present, delay the detect event for
+ * about 20ms (to be on the safe side) before reading the socket status.
+ *
+ * Some i82365-based systems send multiple SS_DETECT events during card
+ * insertion, and the "card present" status bit seems to bounce.  This
+ * will probably be true with GPIO-based card detection systems after
+ * the product has aged.
+ */
+static void socket_detect_change(struct pcmcia_socket *skt)
+{
+       if (!(skt->state & SOCKET_SUSPEND)) {
+               int status;
+
+               if (!(skt->state & SOCKET_PRESENT)) {
+                       set_current_state(TASK_UNINTERRUPTIBLE);
+                       schedule_timeout(cs_to_timeout(2));
+               }
+
+               get_socket_status(skt, &status);
+               if ((skt->state & SOCKET_PRESENT) &&
+                    !(status & SS_DETECT))
+                       socket_remove(skt);
+               if (!(skt->state & SOCKET_PRESENT) &&
+                   (status & SS_DETECT))
+                       socket_insert(skt);
+       }
+}
+
 static int pccardd(void *__skt)
 {
        struct pcmcia_socket *skt = __skt;
@@ -817,17 +848,8 @@ static int pccardd(void *__skt)
 
                if (events) {
                        down(&skt->skt_sem);
-                       if (events & SS_DETECT && !(skt->state & SOCKET_SUSPEND)) {
-                               int status;
-
-                               get_socket_status(skt, &status);
-                               if ((skt->state & SOCKET_PRESENT) &&
-                                    !(status & SS_DETECT))
-                                       socket_remove(skt);
-                               if (!(skt->state & SOCKET_PRESENT) &&
-                                   (status & SS_DETECT))
-                                       socket_insert(skt);
-                       }
+                       if (events & SS_DETECT)
+                               socket_detect_change(skt);
                        if (events & SS_BATDEAD)
                                send_event(skt, CS_EVENT_BATTERY_DEAD, CS_EVENT_PRI_LOW);
                        if (events & SS_BATWARN)