pcmcia: delay re-scanning and re-querying of PCMCIA bus

After a CIS update -- or the finalization of the resource database --,
proceed with the re-scanning or re-querying of PCMCIA cards only in
a separate thread to avoid deadlocks.

Tested-by: Wolfram Sang <w.sang@pengutronix.de>
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>

5 files changed, 59 insertions, 53 deletions

diff --git a/drivers/pcmcia/cistpl.c b/drivers/pcmcia/cistpl.c
index 14de287a8bf6..17a5da32cce1 100644
--- a/drivers/pcmcia/cistpl.c
+++ b/drivers/pcmcia/cistpl.c
@@ -1670,15 +1670,7 @@ static ssize_t pccard_store_cis(struct kobject *kobj,
         if (error)
                 return -EIO;
 
-        mutex_lock(&s->skt_mutex);
-        if ((s->callback) && (s->state & SOCKET_PRESENT) &&
-            !(s->state & SOCKET_CARDBUS)) {
-                if (try_module_get(s->callback->owner)) {
-                        s->callback->requery(s, 1);
-                        module_put(s->callback->owner);
-                }
-        }
-        mutex_unlock(&s->skt_mutex);
+        pcmcia_parse_uevents(s, PCMCIA_UEVENT_REQUERY);
 
         return count;
 }
diff --git a/drivers/pcmcia/cs.c b/drivers/pcmcia/cs.c
index 823ecda32216..d529e02c2d54 100644
--- a/drivers/pcmcia/cs.c
+++ b/drivers/pcmcia/cs.c
@@ -728,6 +728,11 @@ static int pccardd(void *__skt)
                                 if (!ret)
                                         socket_suspend(skt);
                         }
+                        if ((sysfs_events & PCMCIA_UEVENT_REQUERY) &&
+                                !(skt->state & SOCKET_CARDBUS)) {
+                                if (!ret && skt->callback)
+                                        skt->callback->requery(skt);
+                        }
                 }
                 mutex_unlock(&skt->skt_mutex);
 
@@ -783,7 +788,8 @@ EXPORT_SYMBOL(pcmcia_parse_events);
  * userspace-issued insert, eject, suspend and resume commands must be
  * handled by pccardd to avoid any sysfs-related deadlocks. Valid events
  * are PCMCIA_UEVENT_EJECT (for eject), PCMCIA_UEVENT__INSERT (for insert),
- * PCMCIA_UEVENT_RESUME (for resume) and PCMCIA_UEVENT_SUSPEND (for suspend).
+ * PCMCIA_UEVENT_RESUME (for resume), PCMCIA_UEVENT_SUSPEND (for suspend)
+ * and PCMCIA_UEVENT_REQUERY (for re-querying the PCMCIA card).
  */
 void pcmcia_parse_uevents(struct pcmcia_socket *s, u_int events)
 {
diff --git a/drivers/pcmcia/cs_internal.h b/drivers/pcmcia/cs_internal.h
index 127c97acf849..f95864c2191e 100644
--- a/drivers/pcmcia/cs_internal.h
+++ b/drivers/pcmcia/cs_internal.h
@@ -110,7 +110,7 @@ struct pcmcia_callback{
         struct module   *owner;
         int             (*event) (struct pcmcia_socket *s,
                                   event_t event, int priority);
-        void            (*requery) (struct pcmcia_socket *s, int new_cis);
+        void            (*requery) (struct pcmcia_socket *s);
         int             (*validate) (struct pcmcia_socket *s, unsigned int *i);
         int             (*suspend) (struct pcmcia_socket *s);
         int             (*resume) (struct pcmcia_socket *s);
@@ -129,6 +129,7 @@ void pcmcia_parse_uevents(struct pcmcia_socket *socket, unsigned int events);
 #define PCMCIA_UEVENT_INSERT    0x0002
 #define PCMCIA_UEVENT_SUSPEND   0x0004
 #define PCMCIA_UEVENT_RESUME    0x0008
+#define PCMCIA_UEVENT_REQUERY   0x0010
 
 struct pcmcia_socket *pcmcia_get_socket(struct pcmcia_socket *skt);
 void pcmcia_put_socket(struct pcmcia_socket *skt);
diff --git a/drivers/pcmcia/ds.c b/drivers/pcmcia/ds.c
index 76a21638291b..5400e20c664e 100644
--- a/drivers/pcmcia/ds.c
+++ b/drivers/pcmcia/ds.c
@@ -432,16 +432,20 @@ static int pcmcia_device_query(struct pcmcia_device *p_dev)
 
         if (!pccard_read_tuple(p_dev->socket, BIND_FN_ALL,
                                CISTPL_MANFID, &manf_id)) {
+                mutex_lock(&p_dev->socket->ops_mutex);
                 p_dev->manf_id = manf_id.manf;
                 p_dev->card_id = manf_id.card;
                 p_dev->has_manf_id = 1;
                 p_dev->has_card_id = 1;
+                mutex_unlock(&p_dev->socket->ops_mutex);
         }
 
         if (!pccard_read_tuple(p_dev->socket, p_dev->func,
                                CISTPL_FUNCID, &func_id)) {
+                mutex_lock(&p_dev->socket->ops_mutex);
                 p_dev->func_id = func_id.func;
                 p_dev->has_func_id = 1;
+                mutex_unlock(&p_dev->socket->ops_mutex);
         } else {
                 /* rule of thumb: cards with no FUNCID, but with
                  * common memory device geometry information, are
@@ -458,14 +462,17 @@ static int pcmcia_device_query(struct pcmcia_device *p_dev)
                         dev_dbg(&p_dev->dev,
                                    "mem device geometry probably means "
                                    "FUNCID_MEMORY\n");
+                        mutex_lock(&p_dev->socket->ops_mutex);
                         p_dev->func_id = CISTPL_FUNCID_MEMORY;
                         p_dev->has_func_id = 1;
+                        mutex_unlock(&p_dev->socket->ops_mutex);
                 }
                 kfree(devgeo);
         }
 
         if (!pccard_read_tuple(p_dev->socket, BIND_FN_ALL, CISTPL_VERS_1,
                                vers1)) {
+                mutex_lock(&p_dev->socket->ops_mutex);
                 for (i = 0; i < min_t(unsigned int, 4, vers1->ns); i++) {
                         char *tmp;
                         unsigned int length;
@@ -484,6 +491,7 @@ static int pcmcia_device_query(struct pcmcia_device *p_dev)
                         p_dev->prod_id[i] = strncpy(p_dev->prod_id[i],
                                                     tmp, length);
                 }
+                mutex_unlock(&p_dev->socket->ops_mutex);
         }
 
         kfree(vers1);
@@ -660,7 +668,7 @@ static void pcmcia_delayed_add_device(struct work_struct *work)
         pcmcia_device_add(s, mfc_pfc);
 }
 
-static int pcmcia_requery(struct device *dev, void * _data)
+static int pcmcia_requery_callback(struct device *dev, void * _data)
 {
         struct pcmcia_device *p_dev = to_pcmcia_dev(dev);
         if (!p_dev->dev.driver) {
@@ -671,44 +679,57 @@ static int pcmcia_requery(struct device *dev, void * _data)
         return 0;
 }
 
-static void pcmcia_bus_rescan(struct pcmcia_socket *skt, int new_cis)
+static void pcmcia_requery(struct pcmcia_socket *s)
 {
-        int no_devices = 0;
-        int ret = 0;
-
-        /* must be called with skt_mutex held */
-        dev_dbg(&skt->dev, "re-scanning socket %d\n", skt->sock);
+        int present;
 
-        mutex_lock(&skt->ops_mutex);
-        if (list_empty(&skt->devices_list))
-                no_devices = 1;
-        mutex_unlock(&skt->ops_mutex);
+        mutex_lock(&s->ops_mutex);
+        present = s->pcmcia_state.present;
+        mutex_unlock(&s->ops_mutex);
 
-        /* If this is because of a CIS override, start over */
-        if (new_cis && !no_devices)
-                pcmcia_card_remove(skt, NULL);
+        if (!present)
+                return;
 
-        /* if no devices were added for this socket yet because of
-         * missing resource information or other trouble, we need to
-         * do this now. */
-        if (no_devices || new_cis) {
-                ret = pcmcia_card_add(skt);
-                if (ret)
-                        return;
+        if (s->functions == 0) {
+                pcmcia_card_add(s);
+                return;
         }
 
         /* some device information might have changed because of a CIS
          * update or because we can finally read it correctly... so
          * determine it again, overwriting old values if necessary. */
-        bus_for_each_dev(&pcmcia_bus_type, NULL, NULL, pcmcia_requery);
+        bus_for_each_dev(&pcmcia_bus_type, NULL, NULL, pcmcia_requery_callback);
+
+        /* if the CIS changed, we need to check whether the number of
+         * functions changed. */
+        if (s->fake_cis) {
+                int old_funcs, new_funcs;
+                cistpl_longlink_mfc_t mfc;
+
+                /* does this cis override add or remove functions? */
+                old_funcs = s->functions;
+
+                if (!pccard_read_tuple(s, BIND_FN_ALL, CISTPL_LONGLINK_MFC,
+                                        &mfc))
+                        new_funcs = mfc.nfn;
+                else
+                        new_funcs = 1;
+                if (old_funcs > new_funcs) {
+                        pcmcia_card_remove(s, NULL);
+                        pcmcia_card_add(s);
+                } else if (new_funcs > old_funcs) {
+                        s->functions = new_funcs;
+                        pcmcia_device_add(s, 1);
+                }
+        }
 
         /* we re-scan all devices, not just the ones connected to this
          * socket. This does not matter, though. */
-        ret = bus_rescan_devices(&pcmcia_bus_type);
-        if (ret)
-                printk(KERN_INFO "pcmcia: bus_rescan_devices failed\n");
+        if (bus_rescan_devices(&pcmcia_bus_type))
+                dev_warn(&s->dev, "rescanning the bus failed\n");
 }
 
+
 #ifdef CONFIG_PCMCIA_LOAD_CIS
 
 /**
@@ -1085,7 +1106,6 @@ static ssize_t pcmcia_store_allow_func_id_match(struct device *dev,
                 struct device_attribute *attr, const char *buf, size_t count)
 {
         struct pcmcia_device *p_dev = to_pcmcia_dev(dev);
-        int ret;
 
         if (!count)
                 return -EINVAL;
@@ -1093,11 +1113,7 @@ static ssize_t pcmcia_store_allow_func_id_match(struct device *dev,
         mutex_lock(&p_dev->socket->ops_mutex);
         p_dev->allow_func_id_match = 1;
         mutex_unlock(&p_dev->socket->ops_mutex);
-
-        ret = bus_rescan_devices(&pcmcia_bus_type);
-        if (ret)
-                printk(KERN_INFO "pcmcia: bus_rescan_devices failed after "
-                       "allowing func_id matches\n");
+        pcmcia_parse_uevents(p_dev->socket, PCMCIA_UEVENT_REQUERY);
 
         return count;
 }
@@ -1359,7 +1375,7 @@ EXPORT_SYMBOL(pcmcia_dev_present);
 static struct pcmcia_callback pcmcia_bus_callback = {
         .owner = THIS_MODULE,
         .event = ds_event,
-        .requery = pcmcia_bus_rescan,
+        .requery = pcmcia_requery,
         .validate = pccard_validate_cis,
         .suspend = pcmcia_bus_suspend,
         .resume = pcmcia_bus_resume,
diff --git a/drivers/pcmcia/socket_sysfs.c b/drivers/pcmcia/socket_sysfs.c
index fba0e30183f4..08278016e58d 100644
--- a/drivers/pcmcia/socket_sysfs.c
+++ b/drivers/pcmcia/socket_sysfs.c
@@ -201,16 +201,7 @@ static ssize_t pccard_store_resource(struct device *dev,
                 s->resource_setup_done = 1;
         mutex_unlock(&s->ops_mutex);
 
-        mutex_lock(&s->skt_mutex);
-        if ((s->callback) &&
-            (s->state & SOCKET_PRESENT) &&
-            !(s->state & SOCKET_CARDBUS)) {
-                if (try_module_get(s->callback->owner)) {
-                        s->callback->requery(s, 0);
-                        module_put(s->callback->owner);
-                }
-        }
-        mutex_unlock(&s->skt_mutex);
+        pcmcia_parse_uevents(s, PCMCIA_UEVENT_REQUERY);
 
         return count;
 }