CAPI: Rework capi_ctr_ready/down

This step prepares the application of proper controller locking: Push
all state changing work into the notify handler that are called by
capi_ctr_ready and capi_ctr_down, switch detach_capi_ctr to issue a
synchronous ctr_down. Also ensure that we do not go through any action
if the state did not change.

Signed-off-by: Jan Kiszka <jan.kiszka@web.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 50 insertions, 45 deletions

diff --git a/drivers/isdn/capi/kcapi.c b/drivers/isdn/capi/kcapi.c
index c46964fc17c7..9362a7a66aa1 100644
--- a/drivers/isdn/capi/kcapi.c
+++ b/drivers/isdn/capi/kcapi.c
@@ -169,44 +169,74 @@ static void release_appl(struct capi_ctr *ctr, u16 applid)
 
 static void notify_up(u32 contr)
 {
-        struct capi_ctr *ctr = get_capi_ctr_by_nr(contr);
         struct capi20_appl *ap;
+        struct capi_ctr *ctr;
         u16 applid;
 
-        if (showcapimsgs & 1) {
+        if (showcapimsgs & 1)
                 printk(KERN_DEBUG "kcapi: notify up contr %d\n", contr);
-        }
-        if (!ctr) {
+
+        ctr = get_capi_ctr_by_nr(contr);
+        if (ctr) {
+                if (ctr->state == CAPI_CTR_RUNNING)
+                        return;
+
+                ctr->state = CAPI_CTR_RUNNING;
+
+                for (applid = 1; applid <= CAPI_MAXAPPL; applid++) {
+                        ap = get_capi_appl_by_nr(applid);
+                        if (!ap || ap->release_in_progress)
+                                continue;
+                        register_appl(ctr, applid, &ap->rparam);
+                        if (ap->callback && !ap->release_in_progress)
+                                ap->callback(KCI_CONTRUP, contr,
+                                             &ctr->profile);
+                }
+        } else
                 printk(KERN_WARNING "%s: invalid contr %d\n", __func__, contr);
-                return;
-        }
-        for (applid = 1; applid <= CAPI_MAXAPPL; applid++) {
-                ap = get_capi_appl_by_nr(applid);
-                if (!ap || ap->release_in_progress) continue;
-                register_appl(ctr, applid, &ap->rparam);
-                if (ap->callback && !ap->release_in_progress)
-                        ap->callback(KCI_CONTRUP, contr, &ctr->profile);
-        }
 }
 
 /* -------- KCI_CONTRDOWN ------------------------------------- */
 
-static void notify_down(u32 contr)
+static void ctr_down(struct capi_ctr *ctr)
 {
         struct capi20_appl *ap;
         u16 applid;
 
-        if (showcapimsgs & 1) {
-                printk(KERN_DEBUG "kcapi: notify down contr %d\n", contr);
-        }
+        if (ctr->state == CAPI_CTR_DETECTED)
+                return;
+
+        ctr->state = CAPI_CTR_DETECTED;
+
+        memset(ctr->manu, 0, sizeof(ctr->manu));
+        memset(&ctr->version, 0, sizeof(ctr->version));
+        memset(&ctr->profile, 0, sizeof(ctr->profile));
+        memset(ctr->serial, 0, sizeof(ctr->serial));
 
         for (applid = 1; applid <= CAPI_MAXAPPL; applid++) {
                 ap = get_capi_appl_by_nr(applid);
-                if (ap && ap->callback && !ap->release_in_progress)
-                        ap->callback(KCI_CONTRDOWN, contr, NULL);
+                if (ap && !ap->release_in_progress) {
+                        if (ap->callback)
+                                ap->callback(KCI_CONTRDOWN, ctr->cnr, NULL);
+                        capi_ctr_put(ctr);
+                }
         }
 }
 
+static void notify_down(u32 contr)
+{
+        struct capi_ctr *ctr;
+
+        if (showcapimsgs & 1)
+                printk(KERN_DEBUG "kcapi: notify down contr %d\n", contr);
+
+        ctr = get_capi_ctr_by_nr(contr);
+        if (ctr)
+                ctr_down(ctr);
+        else
+                printk(KERN_WARNING "%s: invalid contr %d\n", __func__, contr);
+}
+
 static void notify_handler(struct work_struct *work)
 {
         struct capi_notifier *np =
@@ -368,8 +398,6 @@ EXPORT_SYMBOL(capi_ctr_handle_message);
 
 void capi_ctr_ready(struct capi_ctr *ctr)
 {
-        ctr->state = CAPI_CTR_RUNNING;
-
         printk(KERN_NOTICE "kcapi: controller [%03d] \"%s\" ready.\n",
                ctr->cnr, ctr->name);
 
@@ -388,28 +416,6 @@ EXPORT_SYMBOL(capi_ctr_ready);
 
 void capi_ctr_down(struct capi_ctr *ctr)
 {
-        u16 appl;
-
-        DBG("");
-
-        if (ctr->state == CAPI_CTR_DETECTED)
-                return;
-
-        ctr->state = CAPI_CTR_DETECTED;
-
-        memset(ctr->manu, 0, sizeof(ctr->manu));
-        memset(&ctr->version, 0, sizeof(ctr->version));
-        memset(&ctr->profile, 0, sizeof(ctr->profile));
-        memset(ctr->serial, 0, sizeof(ctr->serial));
-
-        for (appl = 1; appl <= CAPI_MAXAPPL; appl++) {
-                struct capi20_appl *ap = get_capi_appl_by_nr(appl);
-                if (!ap || ap->release_in_progress)
-                        continue;
-
-                capi_ctr_put(ctr);
-        }
-
         printk(KERN_NOTICE "kcapi: controller [%03d] down.\n", ctr->cnr);
 
         notify_push(KCI_CONTRDOWN, ctr->cnr, 0, 0);
@@ -513,8 +519,7 @@ EXPORT_SYMBOL(attach_capi_ctr);
 
 int detach_capi_ctr(struct capi_ctr *ctr)
 {
-        if (ctr->state != CAPI_CTR_DETECTED)
-                capi_ctr_down(ctr);
+        ctr_down(ctr);
 
         ncontrollers--;