s390/sclp: avoid merged message output

The sclp console and tty code currently uses several message text
objects in a single message event to print several lines with one
SCCB. This causes the output of these lines to be fused into a
block which is noticeable when selecting text in the operating system
message panel.

Instead use several message events with a single message text object
each to print every line on its own. This changes the SCCB layout
from

    struct sccb_header
        struct evbuf_header
            struct mdb_header
                struct go
                struct mto
		...
		struct mto

to

    struct sccb_header
        struct evbuf_header
            struct mdb_header
                struct go
                struct mto
	...
        struct evbuf_header
            struct mdb_header
                struct go
                struct mto

Reviewed-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

1 files changed, 4 insertions, 4 deletions

diff --git a/drivers/s390/char/sclp_tty.c b/drivers/s390/char/sclp_tty.c
index 003663288e29..3c6e174e19b6 100644
--- a/drivers/s390/char/sclp_tty.c
+++ b/drivers/s390/char/sclp_tty.c
@@ -84,8 +84,8 @@ sclp_tty_close(struct tty_struct *tty, struct file *filp)
  * to change as output buffers get emptied, or if the output flow
  * control is acted. This is not an exact number because not every
  * character needs the same space in the sccb. The worst case is
- * a string of newlines. Every newlines creates a new mto which
- * needs 8 bytes.
+ * a string of newlines. Every newline creates a new message which
+ * needs 82 bytes.
  */
 static int
 sclp_tty_write_room (struct tty_struct *tty)
@@ -97,9 +97,9 @@ sclp_tty_write_room (struct tty_struct *tty)
 	spin_lock_irqsave(&sclp_tty_lock, flags);
 	count = 0;
 	if (sclp_ttybuf != NULL)
-		count = sclp_buffer_space(sclp_ttybuf) / sizeof(struct mto);
+		count = sclp_buffer_space(sclp_ttybuf) / sizeof(struct msg_buf);
 	list_for_each(l, &sclp_tty_pages)
-		count += NR_EMPTY_MTO_PER_SCCB;
+		count += NR_EMPTY_MSG_PER_SCCB;
 	spin_unlock_irqrestore(&sclp_tty_lock, flags);
 	return count;
 }