[S390] 3215: Remove tasklet.
The 3215 console irq handler used to schedule a tasklet. However the
console irq handler also gets called from the infamous cio_tpi()
function. Which in turn does something like
local_bh_disable()
[call console irq handler]
_local_bh_enable()
_local_bh_enable() prevents execution of softirqs, which is intended
within cio_tpi(). However there might be a new softirq pending because
irq handler scheduled a tasklet.
In order to prevent this behaviour we just get rid of the tasklet.
It's not doing much anyway.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/drivers/s390/char/con3215.c b/drivers/s390/char/con3215.c
index 982cf62..9ab06e0 100644
--- a/drivers/s390/char/con3215.c
+++ b/drivers/s390/char/con3215.c
@@ -89,7 +89,6 @@
int count; /* number of bytes in output buffer */
int written; /* number of bytes in write requests */
struct tty_struct *tty; /* pointer to tty structure if present */
- struct tasklet_struct tasklet;
struct raw3215_req *queued_read; /* pointer to queued read requests */
struct raw3215_req *queued_write;/* pointer to queued write requests */
wait_queue_head_t empty_wait; /* wait queue for flushing */
@@ -342,21 +341,14 @@
}
/*
- * The bottom half handler routine for 3215 devices. It tries to start
- * the next IO and wakes up processes waiting on the tty.
+ * Try to start the next IO and wake up processes waiting on the tty.
*/
-static void
-raw3215_tasklet(void *data)
+static void raw3215_next_io(struct raw3215_info *raw)
{
- struct raw3215_info *raw;
struct tty_struct *tty;
- unsigned long flags;
- raw = (struct raw3215_info *) data;
- spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
raw3215_mk_write_req(raw);
raw3215_try_io(raw);
- spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
tty = raw->tty;
if (tty != NULL &&
RAW3215_BUFFER_SIZE - raw->count >= RAW3215_MIN_SPACE) {
@@ -381,7 +373,7 @@
cstat = irb->scsw.cmd.cstat;
dstat = irb->scsw.cmd.dstat;
if (cstat != 0)
- tasklet_schedule(&raw->tasklet);
+ raw3215_next_io(raw);
if (dstat & 0x01) { /* we got a unit exception */
dstat &= ~0x01; /* we can ignore it */
}
@@ -391,7 +383,7 @@
break;
/* Attention interrupt, someone hit the enter key */
raw3215_mk_read_req(raw);
- tasklet_schedule(&raw->tasklet);
+ raw3215_next_io(raw);
break;
case 0x08:
case 0x0C:
@@ -449,7 +441,7 @@
raw->queued_read == NULL) {
wake_up_interruptible(&raw->empty_wait);
}
- tasklet_schedule(&raw->tasklet);
+ raw3215_next_io(raw);
break;
default:
/* Strange interrupt, I'll do my best to clean up */
@@ -461,7 +453,7 @@
raw->flags &= ~RAW3215_WORKING;
raw3215_free_req(req);
}
- tasklet_schedule(&raw->tasklet);
+ raw3215_next_io(raw);
}
return;
}
@@ -675,9 +667,6 @@
kfree(raw);
return -ENOMEM;
}
- tasklet_init(&raw->tasklet,
- (void (*)(unsigned long)) raw3215_tasklet,
- (unsigned long) raw);
init_waitqueue_head(&raw->empty_wait);
cdev->dev.driver_data = raw;
@@ -863,9 +852,6 @@
cdev->handler = raw3215_irq;
raw->flags |= RAW3215_FIXED;
- tasklet_init(&raw->tasklet,
- (void (*)(unsigned long)) raw3215_tasklet,
- (unsigned long) raw);
init_waitqueue_head(&raw->empty_wait);
/* Request the console irq */