[PATCH] isdn4linux: Siemens Gigaset drivers: make some variables non-atomic

With Hansjoerg Lipp <hjlipp@web.de>

Replace some atomic_t variables in the Gigaset drivers by non-atomic ones,
using spinlocks instead to assure atomicity, as proposed in discussions on the
linux-kernel mailing list.

Signed-off-by: Hansjoerg Lipp <hjlipp@web.de>
Signed-off-by: Tilman Schmidt <tilman@imap.cc>
Cc: Karsten Keil <kkeil@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 32 insertions, 32 deletions

diff --git a/drivers/isdn/gigaset/common.c b/drivers/isdn/gigaset/common.c
index f8e5759c636c..d00acddd6213 100644
--- a/drivers/isdn/gigaset/common.c
+++ b/drivers/isdn/gigaset/common.c
@@ -129,11 +129,6 @@ int gigaset_enterconfigmode(struct cardstate *cs)
 {
         int i, r;
 
-        if (!atomic_read(&cs->connected)) {
-                err("not connected!");
-                return -1;
-        }
-
         cs->control_state = TIOCM_RTS; //FIXME
 
         r = setflags(cs, TIOCM_DTR, 200);
@@ -176,7 +171,7 @@ static int test_timeout(struct at_state_t *at_state)
         }
 
         if (!gigaset_add_event(at_state->cs, at_state, EV_TIMEOUT, NULL,
-                               atomic_read(&at_state->timer_index), NULL)) {
+                               at_state->timer_index, NULL)) {
                 //FIXME what should we do?
         }
 
@@ -204,7 +199,7 @@ static void timer_tick(unsigned long data)
                 if (test_timeout(at_state))
                         timeout = 1;
 
-        if (atomic_read(&cs->running)) {
+        if (cs->running) {
                 mod_timer(&cs->timer, jiffies + msecs_to_jiffies(GIG_TICK));
                 if (timeout) {
                         gig_dbg(DEBUG_CMD, "scheduling timeout");
@@ -298,20 +293,22 @@ static void clear_events(struct cardstate *cs)
 {
         struct event_t *ev;
         unsigned head, tail;
+        unsigned long flags;
 
-        /* no locking needed (no reader/writer allowed) */
+        spin_lock_irqsave(&cs->ev_lock, flags);
 
-        head = atomic_read(&cs->ev_head);
-        tail = atomic_read(&cs->ev_tail);
+        head = cs->ev_head;
+        tail = cs->ev_tail;
 
         while (tail != head) {
                 ev = cs->events + head;
                 kfree(ev->ptr);
-
                 head = (head + 1) % MAX_EVENTS;
         }
 
-        atomic_set(&cs->ev_head, tail);
+        cs->ev_head = tail;
+
+        spin_unlock_irqrestore(&cs->ev_lock, flags);
 }
 
 struct event_t *gigaset_add_event(struct cardstate *cs,
@@ -324,9 +321,9 @@ struct event_t *gigaset_add_event(struct cardstate *cs,
 
         spin_lock_irqsave(&cs->ev_lock, flags);
 
-        tail = atomic_read(&cs->ev_tail);
+        tail = cs->ev_tail;
         next = (tail + 1) % MAX_EVENTS;
-        if (unlikely(next == atomic_read(&cs->ev_head)))
+        if (unlikely(next == cs->ev_head))
                 err("event queue full");
         else {
                 event = cs->events + tail;
@@ -336,7 +333,7 @@ struct event_t *gigaset_add_event(struct cardstate *cs,
                 event->ptr = ptr;
                 event->arg = arg;
                 event->parameter = parameter;
-                atomic_set(&cs->ev_tail, next);
+                cs->ev_tail = next;
         }
 
         spin_unlock_irqrestore(&cs->ev_lock, flags);
@@ -454,7 +451,7 @@ void gigaset_freecs(struct cardstate *cs)
                 goto f_bcs;
 
         spin_lock_irqsave(&cs->lock, flags);
-        atomic_set(&cs->running, 0);
+        cs->running = 0;
         spin_unlock_irqrestore(&cs->lock, flags); /* event handler and timer are
                                                      not rescheduled below */
 
@@ -513,8 +510,8 @@ void gigaset_at_init(struct at_state_t *at_state, struct bc_state *bcs,
         at_state->pending_commands = 0;
         at_state->timer_expires = 0;
         at_state->timer_active = 0;
-        atomic_set(&at_state->timer_index, 0);
-        atomic_set(&at_state->seq_index, 0);
+        at_state->timer_index = 0;
+        at_state->seq_index = 0;
         at_state->ConState = 0;
         for (i = 0; i < STR_NUM; ++i)
                 at_state->str_var[i] = NULL;
@@ -665,6 +662,7 @@ struct cardstate *gigaset_initcs(struct gigaset_driver *drv, int channels,
                                  int cidmode, const char *modulename)
 {
         struct cardstate *cs = NULL;
+        unsigned long flags;
         int i;
 
         gig_dbg(DEBUG_INIT, "allocating cs");
@@ -685,11 +683,11 @@ struct cardstate *gigaset_initcs(struct gigaset_driver *drv, int channels,
         cs->onechannel = onechannel;
         cs->ignoreframes = ignoreframes;
         INIT_LIST_HEAD(&cs->temp_at_states);
-        atomic_set(&cs->running, 0);
+        cs->running = 0;
         init_timer(&cs->timer); /* clear next & prev */
         spin_lock_init(&cs->ev_lock);
-        atomic_set(&cs->ev_tail, 0);
-        atomic_set(&cs->ev_head, 0);
+        cs->ev_tail = 0;
+        cs->ev_head = 0;
         mutex_init(&cs->mutex);
         mutex_lock(&cs->mutex);
 
@@ -701,7 +699,7 @@ struct cardstate *gigaset_initcs(struct gigaset_driver *drv, int channels,
         cs->open_count = 0;
         cs->dev = NULL;
         cs->tty = NULL;
-        atomic_set(&cs->cidmode, cidmode != 0);
+        cs->cidmode = cidmode != 0;
 
         //if(onechannel) { //FIXME
                 cs->tabnocid = gigaset_tab_nocid_m10x;
@@ -737,7 +735,8 @@ struct cardstate *gigaset_initcs(struct gigaset_driver *drv, int channels,
         } else
                 gigaset_inbuf_init(cs->inbuf, NULL,    cs, INS_command);
 
-        atomic_set(&cs->connected, 0);
+        cs->connected = 0;
+        cs->isdn_up = 0;
 
         gig_dbg(DEBUG_INIT, "setting up cmdbuf");
         cs->cmdbuf = cs->lastcmdbuf = NULL;
@@ -761,7 +760,9 @@ struct cardstate *gigaset_initcs(struct gigaset_driver *drv, int channels,
 
         gigaset_if_init(cs);
 
-        atomic_set(&cs->running, 1);
+        spin_lock_irqsave(&cs->lock, flags);
+        cs->running = 1;
+        spin_unlock_irqrestore(&cs->lock, flags);
         setup_timer(&cs->timer, timer_tick, (unsigned long) cs);
         cs->timer.expires = jiffies + msecs_to_jiffies(GIG_TICK);
         /* FIXME: can jiffies increase too much until the timer is added?
@@ -871,10 +872,14 @@ static void cleanup_cs(struct cardstate *cs)
 
 int gigaset_start(struct cardstate *cs)
 {
+        unsigned long flags;
+
         if (mutex_lock_interruptible(&cs->mutex))
                 return 0;
 
-        atomic_set(&cs->connected, 1);
+        spin_lock_irqsave(&cs->lock, flags);
+        cs->connected = 1;
+        spin_unlock_irqrestore(&cs->lock, flags);
 
         if (atomic_read(&cs->mstate) != MS_LOCKED) {
                 cs->ops->set_modem_ctrl(cs, 0, TIOCM_DTR|TIOCM_RTS);
@@ -950,11 +955,6 @@ void gigaset_stop(struct cardstate *cs)
 {
         mutex_lock(&cs->mutex);
 
-        /* clear device sysfs */
-        gigaset_free_dev_sysfs(cs);
-
-        atomic_set(&cs->connected, 0);
-
         cs->waiting = 1;
 
         if (!gigaset_add_event(cs, &cs->at_state, EV_STOP, NULL, 0, NULL)) {
@@ -970,8 +970,8 @@ void gigaset_stop(struct cardstate *cs)
                 //FIXME
         }
 
-        /* Tell the LL that the device is not available .. */
-        gigaset_i4l_cmd(cs, ISDN_STAT_STOP); // FIXME move to event layer?
+        /* clear device sysfs */
+        gigaset_free_dev_sysfs(cs);
 
         cleanup_cs(cs);