[PATCH 2.6] PPC64: janitorial HVSI use wait_event_timeout()

[Linas Vepstas]

Hi,

I seem to be dragging around the following janitorial patch, it was 
submitted upstream to LKML on March 6 2005, but seems not to have made 
it in.  Hollis, please review; I've been running with it for months.

--linas

Use wait_event_timeout() in place of custom wait-queue code. The
code is not changed in any way (I don't think), but is cleaned up quite a bit
(will get expanded to almost identical code).

Acked-by: Linas Vepstas <linas at austin.ibm.com>
Signed-off-by: Nishanth Aravamudan <nacc at us.ibm.com>
Signed-off-by: Domen Puncer <domen at coderock.org>

--- linux-2.6.11.8/drivers/char/hvsi.c.linas-orig	2005-04-29 20:29:25.000000000 -0500
+++ linux-2.6.11.8/drivers/char/hvsi.c	2005-05-06 12:28:43.000000000 -0500
@@ -44,6 +44,7 @@
 #include <linux/sysrq.h>
 #include <linux/tty.h>
 #include <linux/tty_flip.h>
+#include <linux/wait.h>
 #include <asm/hvcall.h>
 #include <asm/hvconsole.h>
 #include <asm/prom.h>
@@ -631,27 +632,9 @@ static int __init poll_for_state(struct 
 /* wait for irq handler to change our state */
 static int wait_for_state(struct hvsi_struct *hp, int state)
 {
-	unsigned long end_jiffies = jiffies + HVSI_TIMEOUT;
-	unsigned long timeout;
-	int ret = 0;
-
-	DECLARE_WAITQUEUE(myself, current);
-	set_current_state(TASK_INTERRUPTIBLE);
-	add_wait_queue(&hp->stateq, &myself);
-
-	for (;;) {
-		set_current_state(TASK_INTERRUPTIBLE);
-		if (hp->state == state)
-			break;
-		timeout = end_jiffies - jiffies;
-		if (time_after(jiffies, end_jiffies)) {
-			ret = -EIO;
-			break;
-		}
-		schedule_timeout(timeout);
-	}
-	remove_wait_queue(&hp->stateq, &myself);
-	set_current_state(TASK_RUNNING);
+	int ret=0;
+	if(!wait_event_timeout(hp->stateq, (hp->state == state), jiffies +
+									 HVSI_TIMEOUT)) ret = -EIO;
 
 	return ret;
 }
@@ -868,24 +851,8 @@ static int hvsi_open(struct tty_struct *
 /* wait for hvsi_write_worker to empty hp->outbuf */
 static void hvsi_flush_output(struct hvsi_struct *hp)
 {
-	unsigned long end_jiffies = jiffies + HVSI_TIMEOUT;
-	unsigned long timeout;
-
-	DECLARE_WAITQUEUE(myself, current);
-	set_current_state(TASK_UNINTERRUPTIBLE);
-	add_wait_queue(&hp->emptyq, &myself);
-
-	for (;;) {
-		set_current_state(TASK_UNINTERRUPTIBLE);
-		if (hp->n_outbuf <= 0)
-			break;
-		timeout = end_jiffies - jiffies;
-		if (time_after(jiffies, end_jiffies))
-			break;
-		schedule_timeout(timeout);
-	}
-	remove_wait_queue(&hp->emptyq, &myself);
-	set_current_state(TASK_RUNNING);
+	wait_event_timeout(hp->emptyq, (hp->n_outbuf <= 0), jiffies +
+						  HVSI_TIMEOUT);
 
 	/* 'writer' could still be pending if it didn't see n_outbuf = 0 yet */
 	cancel_delayed_work(&hp->writer);