1 files changed, 79 insertions, 39 deletions

diff --git a/drivers/s390/char/sclp_vt220.c b/drivers/s390/char/sclp_vt220.c
index a839aa531d7c..5518e24946aa 100644
--- a/drivers/s390/char/sclp_vt220.c
+++ b/drivers/s390/char/sclp_vt220.c
@@ -1,10 +1,9 @@
 /*
- *  drivers/s390/char/sclp_vt220.c
- *    SCLP VT220 terminal driver.
+ * SCLP VT220 terminal driver.
  *
- *  S390 version
- *    Copyright IBM Corp. 2003,2008
- *    Author(s): Peter Oberparleiter <Peter.Oberparleiter@de.ibm.com>
+ * Copyright IBM Corp. 2003, 2009
+ *
+ * Author(s): Peter Oberparleiter <Peter.Oberparleiter@de.ibm.com>
  */
 
 #include <linux/module.h>
@@ -69,8 +68,11 @@ static struct list_head sclp_vt220_empty;
 /* List of pending requests */
 static struct list_head sclp_vt220_outqueue;
 
-/* Number of requests in outqueue */
-static int sclp_vt220_outqueue_count;
+/* Suspend mode flag */
+static int sclp_vt220_suspended;
+
+/* Flag that output queue is currently running */
+static int sclp_vt220_queue_running;
 
 /* Timer used for delaying write requests to merge subsequent messages into
  * a single buffer */
@@ -92,6 +94,8 @@ static int __initdata sclp_vt220_init_count;
 static int sclp_vt220_flush_later;
 
 static void sclp_vt220_receiver_fn(struct evbuf_header *evbuf);
+static void sclp_vt220_pm_event_fn(struct sclp_register *reg,
+                                   enum sclp_pm_event sclp_pm_event);
 static int __sclp_vt220_emit(struct sclp_vt220_request *request);
 static void sclp_vt220_emit_current(void);
 
@@ -100,7 +104,8 @@ static struct sclp_register sclp_vt220_register = {
         .send_mask              = EVTYP_VT220MSG_MASK,
         .receive_mask           = EVTYP_VT220MSG_MASK,
         .state_change_fn        = NULL,
-        .receiver_fn            = sclp_vt220_receiver_fn
+        .receiver_fn            = sclp_vt220_receiver_fn,
+        .pm_event_fn            = sclp_vt220_pm_event_fn,
 };
 
 
@@ -120,15 +125,19 @@ sclp_vt220_process_queue(struct sclp_vt220_request *request)
                 spin_lock_irqsave(&sclp_vt220_lock, flags);
                 /* Move request from outqueue to empty queue */
                 list_del(&request->list);
-                sclp_vt220_outqueue_count--;
                 list_add_tail((struct list_head *) page, &sclp_vt220_empty);
                 /* Check if there is a pending buffer on the out queue. */
                 request = NULL;
                 if (!list_empty(&sclp_vt220_outqueue))
                         request = list_entry(sclp_vt220_outqueue.next,
                                              struct sclp_vt220_request, list);
+                if (!request || sclp_vt220_suspended) {
+                        sclp_vt220_queue_running = 0;
+                        spin_unlock_irqrestore(&sclp_vt220_lock, flags);
+                        break;
+                }
                 spin_unlock_irqrestore(&sclp_vt220_lock, flags);
-        } while (request && __sclp_vt220_emit(request));
+        } while (__sclp_vt220_emit(request));
         if (request == NULL && sclp_vt220_flush_later)
                 sclp_vt220_emit_current();
         /* Check if the tty needs a wake up call */
@@ -212,26 +221,7 @@ __sclp_vt220_emit(struct sclp_vt220_request *request)
 }
 
 /*
- * Queue and emit given request.
- */
-static void
-sclp_vt220_emit(struct sclp_vt220_request *request)
-{
-        unsigned long flags;
-        int count;
-
-        spin_lock_irqsave(&sclp_vt220_lock, flags);
-        list_add_tail(&request->list, &sclp_vt220_outqueue);
-        count = sclp_vt220_outqueue_count++;
-        spin_unlock_irqrestore(&sclp_vt220_lock, flags);
-        /* Emit only the first buffer immediately - callback takes care of
-         * the rest */
-        if (count == 0 && __sclp_vt220_emit(request))
-                sclp_vt220_process_queue(request);
-}
-
-/*
- * Queue and emit current request. Return zero on success, non-zero otherwise.
+ * Queue and emit current request.
  */
 static void
 sclp_vt220_emit_current(void)
@@ -241,22 +231,33 @@ sclp_vt220_emit_current(void)
         struct sclp_vt220_sccb *sccb;
 
         spin_lock_irqsave(&sclp_vt220_lock, flags);
-        request = NULL;
-        if (sclp_vt220_current_request != NULL) {
+        if (sclp_vt220_current_request) {
                 sccb = (struct sclp_vt220_sccb *) 
                                 sclp_vt220_current_request->sclp_req.sccb;
                 /* Only emit buffers with content */
                 if (sccb->header.length != sizeof(struct sclp_vt220_sccb)) {
-                        request = sclp_vt220_current_request;
+                        list_add_tail(&sclp_vt220_current_request->list,
+                                      &sclp_vt220_outqueue);
                         sclp_vt220_current_request = NULL;
                         if (timer_pending(&sclp_vt220_timer))
                                 del_timer(&sclp_vt220_timer);
                 }
                 sclp_vt220_flush_later = 0;
         }
+        if (sclp_vt220_queue_running || sclp_vt220_suspended)
+                goto out_unlock;
+        if (list_empty(&sclp_vt220_outqueue))
+                goto out_unlock;
+        request = list_first_entry(&sclp_vt220_outqueue,
+                                   struct sclp_vt220_request, list);
+        sclp_vt220_queue_running = 1;
+        spin_unlock_irqrestore(&sclp_vt220_lock, flags);
+
+        if (__sclp_vt220_emit(request))
+                sclp_vt220_process_queue(request);
+        return;
+out_unlock:
         spin_unlock_irqrestore(&sclp_vt220_lock, flags);
-        if (request != NULL)
-                sclp_vt220_emit(request);
 }
 
 #define SCLP_NORMAL_WRITE       0x00
@@ -396,7 +397,7 @@ __sclp_vt220_write(const unsigned char *buf, int count, int do_schedule,
                 if (sclp_vt220_current_request == NULL) {
                         while (list_empty(&sclp_vt220_empty)) {
                                 spin_unlock_irqrestore(&sclp_vt220_lock, flags);
-                                if (may_fail)
+                                if (may_fail || sclp_vt220_suspended)
                                         goto out;
                                 else
                                         sclp_sync_wait();
@@ -531,7 +532,7 @@ sclp_vt220_put_char(struct tty_struct *tty, unsigned char ch)
 static void
 sclp_vt220_flush_chars(struct tty_struct *tty)
 {
-        if (sclp_vt220_outqueue_count == 0)
+        if (!sclp_vt220_queue_running)
                 sclp_vt220_emit_current();
         else
                 sclp_vt220_flush_later = 1;
@@ -635,7 +636,6 @@ static int __init __sclp_vt220_init(int num_pages)
         init_timer(&sclp_vt220_timer);
         sclp_vt220_current_request = NULL;
         sclp_vt220_buffered_chars = 0;
-        sclp_vt220_outqueue_count = 0;
         sclp_vt220_tty = NULL;
         sclp_vt220_flush_later = 0;
 
@@ -736,7 +736,7 @@ static void __sclp_vt220_flush_buffer(void)
         spin_lock_irqsave(&sclp_vt220_lock, flags);
         if (timer_pending(&sclp_vt220_timer))
                 del_timer(&sclp_vt220_timer);
-        while (sclp_vt220_outqueue_count > 0) {
+        while (sclp_vt220_queue_running) {
                 spin_unlock_irqrestore(&sclp_vt220_lock, flags);
                 sclp_sync_wait();
                 spin_lock_irqsave(&sclp_vt220_lock, flags);
@@ -744,6 +744,46 @@ static void __sclp_vt220_flush_buffer(void)
         spin_unlock_irqrestore(&sclp_vt220_lock, flags);
 }
 
+/*
+ * Resume console: If there are cached messages, emit them.
+ */
+static void sclp_vt220_resume(void)
+{
+        unsigned long flags;
+
+        spin_lock_irqsave(&sclp_vt220_lock, flags);
+        sclp_vt220_suspended = 0;
+        spin_unlock_irqrestore(&sclp_vt220_lock, flags);
+        sclp_vt220_emit_current();
+}
+
+/*
+ * Suspend console: Set suspend flag and flush console
+ */
+static void sclp_vt220_suspend(void)
+{
+        unsigned long flags;
+
+        spin_lock_irqsave(&sclp_vt220_lock, flags);
+        sclp_vt220_suspended = 1;
+        spin_unlock_irqrestore(&sclp_vt220_lock, flags);
+        __sclp_vt220_flush_buffer();
+}
+
+static void sclp_vt220_pm_event_fn(struct sclp_register *reg,
+                                   enum sclp_pm_event sclp_pm_event)
+{
+        switch (sclp_pm_event) {
+        case SCLP_PM_EVENT_FREEZE:
+                sclp_vt220_suspend();
+                break;
+        case SCLP_PM_EVENT_RESTORE:
+        case SCLP_PM_EVENT_THAW:
+                sclp_vt220_resume();
+                break;
+        }
+}
+
 static int
 sclp_vt220_notify(struct notifier_block *self,
                           unsigned long event, void *data)