tty: make tty_operations::write_room return uint

Line disciplines expect a positive value or zero returned from
tty->ops->write_room (invoked by tty_write_room). So make this
assumption explicit by using unsigned int as a return value. Both of
tty->ops->write_room and tty_write_room.

Signed-off-by: Jiri Slaby <[email protected]>
Acked-by: Laurentiu Tudor <[email protected]>
Acked-by: Alex Elder <[email protected]>
Acked-by: Max Filippov <[email protected]> # xtensa
Acked-by: David Sterba <[email protected]>
Acked-By: Anton Ivanov <[email protected]>
Acked-by: Geert Uytterhoeven <[email protected]>
Cc: Richard Henderson <[email protected]>
Cc: Ivan Kokshaysky <[email protected]>
Cc: Matt Turner <[email protected]>
Cc: "James E.J. Bottomley" <[email protected]>
Cc: Helge Deller <[email protected]>
Cc: Jeff Dike <[email protected]>
Cc: Richard Weinberger <[email protected]>
Cc: Chris Zankel <[email protected]>
Cc: Arnd Bergmann <[email protected]>
Cc: Samuel Iglesias Gonsalvez <[email protected]>
Cc: Jens Taprogge <[email protected]>
Cc: Karsten Keil <[email protected]>
Cc: Scott Branden <[email protected]>
Cc: Ulf Hansson <[email protected]>
Cc: "David S. Miller" <[email protected]>
Cc: Jakub Kicinski <[email protected]>
Cc: Heiko Carstens <[email protected]>
Cc: Vasily Gorbik <[email protected]>
Cc: Christian Borntraeger <[email protected]>
Cc: David Lin <[email protected]>
Cc: Johan Hovold <[email protected]>
Cc: Jiri Kosina <[email protected]>
Cc: Shawn Guo <[email protected]>
Cc: Sascha Hauer <[email protected]>
Cc: Oliver Neukum <[email protected]>
Cc: Felipe Balbi <[email protected]>
Cc: Mathias Nyman <[email protected]>
Cc: Marcel Holtmann <[email protected]>
Cc: Johan Hedberg <[email protected]>
Cc: Luiz Augusto von Dentz <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

1 files changed, 1 insertions, 1 deletions

diff --git a/drivers/mmc/core/sdio_uart.c b/drivers/mmc/core/sdio_uart.c
index dbcac2b7f2fe..c8f4eca7aad4 100644
--- a/drivers/mmc/core/sdio_uart.c
+++ b/drivers/mmc/core/sdio_uart.c
@@ -797,7 +797,7 @@ static int sdio_uart_write(struct tty_struct *tty, const unsigned char *buf,
 	return ret;
 }
 
-static int sdio_uart_write_room(struct tty_struct *tty)
+static unsigned int sdio_uart_write_room(struct tty_struct *tty)
 {
 	struct sdio_uart_port *port = tty->driver_data;
 	return FIFO_SIZE - kfifo_len(&port->xmit_fifo);