Re: [PATCH 3/3] tty: hvc: hvc_write() fix break condition

Commit 550ddadcc758 ("tty: hvc: hvc_write() may sleep") broke the
termination condition in case the driver stops accepting characters.
This can result in unnecessary polling of the busy driver.

Restore it by testing the hvc_push return code.

Fixes: 550ddadcc758 ("tty: hvc: hvc_write() may sleep")
Tested-by: Matteo Croce <redacted>
Tested-by: Leon Romanovsky <redacted>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 drivers/tty/hvc/hvc_console.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/tty/hvc/hvc_console.c b/drivers/tty/hvc/hvc_console.c
index bacf9b73ec98..c09a38fb0d66 100644
--- a/drivers/tty/hvc/hvc_console.c
+++ b/drivers/tty/hvc/hvc_console.c

@@ -522,6 +522,8 @@ static int hvc_write(struct tty_struct *tty, const unsigned char *buf, int count
 		return -EIO;
 
 	while (count > 0) {
+		int ret;
+
 		spin_lock_irqsave(&hp->lock, flags);
 
 		rsize = hp->outbuf_size - hp->n_outbuf;