CAPI: Clean up capiminors_lock

Use a plain spin lock for capiminors_lock, drop inconsistent irqsafe
acquisitions (it's only used in process context anyway).

Signed-off-by: Jan Kiszka <jan.kiszka@web.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/isdn/capi/capi.c b/drivers/isdn/capi/capi.c
index cf5e996..0b264b4 100644
--- a/drivers/isdn/capi/capi.c
+++ b/drivers/isdn/capi/capi.c
@@ -149,7 +149,7 @@
 
 #ifdef CONFIG_ISDN_CAPI_MIDDLEWARE
 
-static DEFINE_RWLOCK(capiminors_lock);
+static DEFINE_SPINLOCK(capiminors_lock);
 static struct capiminor **capiminors;
 
 static struct tty_driver *capinc_tty_driver;
@@ -218,7 +218,6 @@
 	struct capiminor *mp;
 	struct device *dev;
 	unsigned int minor;
-	unsigned long flags;
 
 	mp = kzalloc(sizeof(*mp), GFP_KERNEL);
   	if (!mp) {
@@ -242,13 +241,13 @@
 	mp->port.ops = &capiminor_port_ops;
 
 	/* Allocate the least unused minor number. */
-	write_lock_irqsave(&capiminors_lock, flags);
+	spin_lock(&capiminors_lock);
 	for (minor = 0; minor < capi_ttyminors; minor++)
 		if (!capiminors[minor]) {
 			capiminors[minor] = mp;
 			break;
 		}
-	write_unlock_irqrestore(&capiminors_lock, flags);
+	spin_unlock(&capiminors_lock);
 
 	if (minor == capi_ttyminors) {
 		printk(KERN_NOTICE "capi: out of minors\n");
@@ -264,9 +263,9 @@
 	return mp;
 
 err_out2:
-	write_lock_irqsave(&capiminors_lock, flags);
+	spin_lock(&capiminors_lock);
 	capiminors[minor] = NULL;
-	write_unlock_irqrestore(&capiminors_lock, flags);
+	spin_unlock(&capiminors_lock);
 
 err_out1:
 	kfree(mp);
@@ -288,11 +287,11 @@
 {
 	struct capiminor *mp;
 
-	read_lock(&capiminors_lock);
+	spin_lock(&capiminors_lock);
 	mp = capiminors[minor];
 	if (mp)
 		kref_get(&mp->kref);
-	read_unlock(&capiminors_lock);
+	spin_unlock(&capiminors_lock);
 
 	return mp;
 }
@@ -304,13 +303,11 @@
 
 static void capiminor_free(struct capiminor *mp)
 {
-	unsigned long flags;
-
 	tty_unregister_device(capinc_tty_driver, mp->minor);
 
-	write_lock_irqsave(&capiminors_lock, flags);
+	spin_lock(&capiminors_lock);
 	capiminors[mp->minor] = NULL;
-	write_unlock_irqrestore(&capiminors_lock, flags);
+	spin_unlock(&capiminors_lock);
 
 	capiminor_put(mp);
 }