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-rw-r--r--drivers/s390/char/sclp_vt220.c27
1 files changed, 7 insertions, 20 deletions
diff --git a/drivers/s390/char/sclp_vt220.c b/drivers/s390/char/sclp_vt220.c
index 35707c04e613..62576af36f47 100644
--- a/drivers/s390/char/sclp_vt220.c
+++ b/drivers/s390/char/sclp_vt220.c
@@ -71,9 +71,6 @@ static struct list_head sclp_vt220_outqueue;
71/* Number of requests in outqueue */ 71/* Number of requests in outqueue */
72static int sclp_vt220_outqueue_count; 72static int sclp_vt220_outqueue_count;
73 73
74/* Wait queue used to delay write requests while we've run out of buffers */
75static wait_queue_head_t sclp_vt220_waitq;
76
77/* Timer used for delaying write requests to merge subsequent messages into 74/* Timer used for delaying write requests to merge subsequent messages into
78 * a single buffer */ 75 * a single buffer */
79static struct timer_list sclp_vt220_timer; 76static struct timer_list sclp_vt220_timer;
@@ -133,7 +130,6 @@ sclp_vt220_process_queue(struct sclp_vt220_request *request)
133 } while (request && __sclp_vt220_emit(request)); 130 } while (request && __sclp_vt220_emit(request));
134 if (request == NULL && sclp_vt220_flush_later) 131 if (request == NULL && sclp_vt220_flush_later)
135 sclp_vt220_emit_current(); 132 sclp_vt220_emit_current();
136 wake_up(&sclp_vt220_waitq);
137 /* Check if the tty needs a wake up call */ 133 /* Check if the tty needs a wake up call */
138 if (sclp_vt220_tty != NULL) { 134 if (sclp_vt220_tty != NULL) {
139 tty_wakeup(sclp_vt220_tty); 135 tty_wakeup(sclp_vt220_tty);
@@ -383,7 +379,7 @@ sclp_vt220_timeout(unsigned long data)
383 */ 379 */
384static int 380static int
385__sclp_vt220_write(const unsigned char *buf, int count, int do_schedule, 381__sclp_vt220_write(const unsigned char *buf, int count, int do_schedule,
386 int convertlf, int may_schedule) 382 int convertlf, int may_fail)
387{ 383{
388 unsigned long flags; 384 unsigned long flags;
389 void *page; 385 void *page;
@@ -395,15 +391,14 @@ __sclp_vt220_write(const unsigned char *buf, int count, int do_schedule,
395 overall_written = 0; 391 overall_written = 0;
396 spin_lock_irqsave(&sclp_vt220_lock, flags); 392 spin_lock_irqsave(&sclp_vt220_lock, flags);
397 do { 393 do {
398 /* Create a sclp output buffer if none exists yet */ 394 /* Create an sclp output buffer if none exists yet */
399 if (sclp_vt220_current_request == NULL) { 395 if (sclp_vt220_current_request == NULL) {
400 while (list_empty(&sclp_vt220_empty)) { 396 while (list_empty(&sclp_vt220_empty)) {
401 spin_unlock_irqrestore(&sclp_vt220_lock, flags); 397 spin_unlock_irqrestore(&sclp_vt220_lock, flags);
402 if (in_interrupt() || !may_schedule) 398 if (may_fail)
403 sclp_sync_wait(); 399 goto out;
404 else 400 else
405 wait_event(sclp_vt220_waitq, 401 sclp_sync_wait();
406 !list_empty(&sclp_vt220_empty));
407 spin_lock_irqsave(&sclp_vt220_lock, flags); 402 spin_lock_irqsave(&sclp_vt220_lock, flags);
408 } 403 }
409 page = (void *) sclp_vt220_empty.next; 404 page = (void *) sclp_vt220_empty.next;
@@ -437,6 +432,7 @@ __sclp_vt220_write(const unsigned char *buf, int count, int do_schedule,
437 add_timer(&sclp_vt220_timer); 432 add_timer(&sclp_vt220_timer);
438 } 433 }
439 spin_unlock_irqrestore(&sclp_vt220_lock, flags); 434 spin_unlock_irqrestore(&sclp_vt220_lock, flags);
435out:
440 return overall_written; 436 return overall_written;
441} 437}
442 438
@@ -520,19 +516,11 @@ sclp_vt220_close(struct tty_struct *tty, struct file *filp)
520 * character to the tty device. If the kernel uses this routine, 516 * character to the tty device. If the kernel uses this routine,
521 * it must call the flush_chars() routine (if defined) when it is 517 * it must call the flush_chars() routine (if defined) when it is
522 * done stuffing characters into the driver. 518 * done stuffing characters into the driver.
523 *
524 * NOTE: include/linux/tty_driver.h specifies that a character should be
525 * ignored if there is no room in the queue. This driver implements a different
526 * semantic in that it will block when there is no more room left.
527 *
528 * FIXME: putchar can currently be called from BH and other non blocking
529 * handlers so this semantic isn't a good idea.
530 */ 519 */
531static int 520static int
532sclp_vt220_put_char(struct tty_struct *tty, unsigned char ch) 521sclp_vt220_put_char(struct tty_struct *tty, unsigned char ch)
533{ 522{
534 __sclp_vt220_write(&ch, 1, 0, 0, 1); 523 return __sclp_vt220_write(&ch, 1, 0, 0, 1);
535 return 1;
536} 524}
537 525
538/* 526/*
@@ -653,7 +641,6 @@ static int __init __sclp_vt220_init(void)
653 spin_lock_init(&sclp_vt220_lock); 641 spin_lock_init(&sclp_vt220_lock);
654 INIT_LIST_HEAD(&sclp_vt220_empty); 642 INIT_LIST_HEAD(&sclp_vt220_empty);
655 INIT_LIST_HEAD(&sclp_vt220_outqueue); 643 INIT_LIST_HEAD(&sclp_vt220_outqueue);
656 init_waitqueue_head(&sclp_vt220_waitq);
657 init_timer(&sclp_vt220_timer); 644 init_timer(&sclp_vt220_timer);
658 sclp_vt220_current_request = NULL; 645 sclp_vt220_current_request = NULL;
659 sclp_vt220_buffered_chars = 0; 646 sclp_vt220_buffered_chars = 0;