pcmcia: use state machine for extended requery

The requery callback now also handles the addition of a second pseudo
multifunction device. Avoids messing with dev_{g,s}et_drvdata(), and
fixes any workqueue <-> skt_mutex deadlock.

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

2 files changed, 25 insertions, 78 deletions

diff --git a/drivers/pcmcia/ds.c b/drivers/pcmcia/ds.c
index 5400e20c664e..9968c0d3a5fb 100644
--- a/drivers/pcmcia/ds.c
+++ b/drivers/pcmcia/ds.c
@@ -244,23 +244,11 @@ static void pcmcia_release_dev(struct device *dev)
         kfree(p_dev);
 }
 
-static void pcmcia_add_device_later(struct pcmcia_socket *s, int mfc)
-{
-        if (!s->pcmcia_state.device_add_pending) {
-                dev_dbg(&s->dev, "scheduling to add %s secondary"
-                       " device to %d\n", mfc ? "mfc" : "pfc", s->sock);
-                s->pcmcia_state.device_add_pending = 1;
-                s->pcmcia_state.mfc_pfc = mfc;
-                schedule_work(&s->device_add);
-        }
-        return;
-}
 
 static int pcmcia_device_probe(struct device *dev)
 {
         struct pcmcia_device *p_dev;
         struct pcmcia_driver *p_drv;
-        struct pcmcia_device_id *did;
         struct pcmcia_socket *s;
         cistpl_config_t cis_config;
         int ret = 0;
@@ -273,18 +261,6 @@ static int pcmcia_device_probe(struct device *dev)
         p_drv = to_pcmcia_drv(dev->driver);
         s = p_dev->socket;
 
-        /* The PCMCIA code passes the match data in via dev_set_drvdata(dev)
-         * which is an ugly hack. Once the driver probe is called it may
-         * and often will overwrite the match data so we must save it first
-         *
-         * handle pseudo multifunction devices:
-         * there are at most two pseudo multifunction devices.
-         * if we're matching against the first, schedule a
-         * call which will then check whether there are two
-         * pseudo devices, and if not, add the second one.
-         */
-        did = dev_get_drvdata(&p_dev->dev);
-
         dev_dbg(dev, "trying to bind to %s\n", p_drv->drv.name);
 
         if ((!p_drv->probe) || (!p_dev->function_config) ||
@@ -314,9 +290,9 @@ static int pcmcia_device_probe(struct device *dev)
         }
 
         mutex_lock(&s->ops_mutex);
-        if (did && (did->match_flags & PCMCIA_DEV_ID_MATCH_DEVICE_NO) &&
+        if ((s->pcmcia_state.has_pfc) &&
             (p_dev->socket->device_count == 1) && (p_dev->device_no == 0))
-                pcmcia_add_device_later(p_dev->socket, 0);
+                pcmcia_parse_uevents(s, PCMCIA_UEVENT_REQUERY);
         mutex_unlock(&s->ops_mutex);
 
 put_module:
@@ -369,7 +345,6 @@ static int pcmcia_device_remove(struct device *dev)
 {
         struct pcmcia_device *p_dev;
         struct pcmcia_driver *p_drv;
-        struct pcmcia_device_id *did;
         int i;
 
         p_dev = to_pcmcia_dev(dev);
@@ -381,8 +356,7 @@ static int pcmcia_device_remove(struct device *dev)
          * pseudo multi-function card, we need to unbind
          * all devices
          */
-        did = dev_get_drvdata(&p_dev->dev);
-        if (did && (did->match_flags & PCMCIA_DEV_ID_MATCH_DEVICE_NO) &&
+        if ((p_dev->socket->pcmcia_state.has_pfc) &&
             (p_dev->socket->device_count > 0) &&
             (p_dev->device_no == 0))
                 pcmcia_card_remove(p_dev->socket, p_dev);
@@ -528,8 +502,8 @@ struct pcmcia_device *pcmcia_device_add(struct pcmcia_socket *s, unsigned int fu
         p_dev->device_no = (s->device_count++);
         mutex_unlock(&s->ops_mutex);
 
-        /* max of 4 devices per card */
-        if (p_dev->device_no >= 4)
+        /* max of 2 devices per card */
+        if (p_dev->device_no >= 2)
                 goto err_free;
 
         p_dev->socket = s;
@@ -652,22 +626,6 @@ static int pcmcia_card_add(struct pcmcia_socket *s)
 }
 
 
-static void pcmcia_delayed_add_device(struct work_struct *work)
-{
-        struct pcmcia_socket *s =
-                container_of(work, struct pcmcia_socket, device_add);
-        u8 mfc_pfc;
-
-        mutex_lock(&s->ops_mutex);
-        mfc_pfc = s->pcmcia_state.mfc_pfc;
-        s->pcmcia_state.device_add_pending = 0;
-        s->pcmcia_state.mfc_pfc = 0;
-        mutex_unlock(&s->ops_mutex);
-
-        dev_dbg(&s->dev, "adding additional device to %d\n", s->sock);
-        pcmcia_device_add(s, mfc_pfc);
-}
-
 static int pcmcia_requery_callback(struct device *dev, void * _data)
 {
         struct pcmcia_device *p_dev = to_pcmcia_dev(dev);
@@ -679,9 +637,10 @@ static int pcmcia_requery_callback(struct device *dev, void * _data)
         return 0;
 }
 
+
 static void pcmcia_requery(struct pcmcia_socket *s)
 {
-        int present;
+        int present, has_pfc;
 
         mutex_lock(&s->ops_mutex);
         present = s->pcmcia_state.present;
@@ -723,6 +682,15 @@ static void pcmcia_requery(struct pcmcia_socket *s)
                 }
         }
 
+        /* If the PCMCIA device consists of two pseudo devices,
+         * call pcmcia_device_add() -- which will fail if both
+         * devices are already registered. */
+        mutex_lock(&s->ops_mutex);
+        has_pfc = s->pcmcia_state.has_pfc;
+        mutex_unlock(&s->ops_mutex);
+        if (has_pfc)
+                pcmcia_device_add(s, 0);
+
         /* we re-scan all devices, not just the ones connected to this
          * socket. This does not matter, though. */
         if (bus_rescan_devices(&pcmcia_bus_type))
@@ -746,9 +714,6 @@ static int pcmcia_load_firmware(struct pcmcia_device *dev, char * filename)
         struct pcmcia_socket *s = dev->socket;
         const struct firmware *fw;
         int ret = -ENOMEM;
-        int no_funcs;
-        int old_funcs;
-        cistpl_longlink_mfc_t mfc;
 
         if (!filename)
                 return -EINVAL;
@@ -775,22 +740,8 @@ static int pcmcia_load_firmware(struct pcmcia_device *dev, char * filename)
                 /* update information */
                 pcmcia_device_query(dev);
 
-                /* does this cis override add or remove functions? */
-                old_funcs = s->functions;
-
-                if (!pccard_read_tuple(s, BIND_FN_ALL, CISTPL_LONGLINK_MFC, &mfc))
-                        no_funcs = mfc.nfn;
-                else
-                        no_funcs = 1;
-                s->functions = no_funcs;
-
-                if (old_funcs > no_funcs)
-                        pcmcia_card_remove(s, dev);
-                else if (no_funcs > old_funcs) {
-                        mutex_lock(&s->ops_mutex);
-                        pcmcia_add_device_later(s, 1);
-                        mutex_unlock(&s->ops_mutex);
-                }
+                /* requery (as number of functions might have changed) */
+                pcmcia_parse_uevents(s, PCMCIA_UEVENT_REQUERY);
         }
  release:
         release_firmware(fw);
@@ -857,6 +808,9 @@ static inline int pcmcia_devmatch(struct pcmcia_device *dev,
         if (did->match_flags & PCMCIA_DEV_ID_MATCH_DEVICE_NO) {
                 if (dev->device_no != did->device_no)
                         return 0;
+                mutex_lock(&dev->socket->ops_mutex);
+                dev->socket->pcmcia_state.has_pfc = 1;
+                mutex_unlock(&dev->socket->ops_mutex);
         }
 
         if (did->match_flags & PCMCIA_DEV_ID_MATCH_FUNC_ID) {
@@ -905,8 +859,6 @@ static inline int pcmcia_devmatch(struct pcmcia_device *dev,
                         return 0;
         }
 
-        dev_set_drvdata(&dev->dev, did);
-
         return 1;
 }
 
@@ -1300,6 +1252,7 @@ static int ds_event(struct pcmcia_socket *skt, event_t event, int priority)
 
         case CS_EVENT_CARD_INSERTION:
                 mutex_lock(&s->ops_mutex);
+                s->pcmcia_state.has_pfc = 0;
                 s->pcmcia_state.present = 1;
                 destroy_cis_cache(s); /* to be on the safe side... */
                 mutex_unlock(&s->ops_mutex);
@@ -1411,7 +1364,6 @@ static int __devinit pcmcia_bus_add_socket(struct device *dev,
         init_waitqueue_head(&socket->queue);
 #endif
         INIT_LIST_HEAD(&socket->devices_list);
-        INIT_WORK(&socket->device_add, pcmcia_delayed_add_device);
         memset(&socket->pcmcia_state, 0, sizeof(u8));
         socket->device_count = 0;
 
diff --git a/include/pcmcia/ss.h b/include/pcmcia/ss.h
index ea5dec8c0d76..32896a773910 100644
--- a/include/pcmcia/ss.h
+++ b/include/pcmcia/ss.h
@@ -230,18 +230,13 @@ struct pcmcia_socket {
                 u8                      busy:1;
                 /* pcmcia module is being unloaded */
                 u8                      dead:1;
-                /* a multifunction-device add event is pending */
-                u8                      device_add_pending:1;
-                /* the pending event adds a mfc (1) or pfc (0) */
-                u8                      mfc_pfc:1;
+                /* the PCMCIA card consists of two pseudo devices */
+                u8                      has_pfc:1;
 
-                u8                      reserved:3;
+                u8                      reserved:4;
         } pcmcia_state;
 
 
-        /* for adding further pseudo-multifunction devices */
-        struct work_struct              device_add;
-
 #ifdef CONFIG_PCMCIA_IOCTL
         struct user_info_t              *user;
         wait_queue_head_t               queue;