From 402661daa9557841addb936fdb9a71b0d45a241c Mon Sep 17 00:00:00 2001 From: =?utf8?q?David=20M=C3=BCller?= Date: Wed, 27 Apr 2016 11:58:32 +0200 Subject: [PATCH] serial: 8250_pci: fix divide error bug if baud rate is 0 MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Orabug: 25256918 [ Upstream commit 6f210c18c1c0f016772c8cd51ae12a02bfb9e7ef ] Since commit 21947ba654a6 ("serial: 8250_pci: replace switch-case by formula"), the 8250 driver crashes in the byt_set_termios() function with a divide error. This is caused by the fact that a baud rate of 0 (B0) is not handled properly. Fix it by falling back to B9600 in this case. Signed-off-by: David Müller Fixes: 21947ba654a6 ("serial: 8250_pci: replace switch-case by formula") Cc: stable@vger.kernel.org Suggested-by: Andy Shevchenko Reviewed-by: Andy Shevchenko Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin (cherry picked from commit c91d8c2d38843168a5b58bdc6b809495f5f31863) Signed-off-by: Dhaval Giani --- drivers/tty/serial/8250/8250_pci.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/tty/serial/8250/8250_pci.c b/drivers/tty/serial/8250/8250_pci.c index 9373cca121d3..9d25198cad96 100644 --- a/drivers/tty/serial/8250/8250_pci.c +++ b/drivers/tty/serial/8250/8250_pci.c @@ -1399,6 +1399,9 @@ byt_set_termios(struct uart_port *p, struct ktermios *termios, unsigned long m, n; u32 reg; + /* Gracefully handle the B0 case: fall back to B9600 */ + fuart = fuart ? fuart : 9600 * 16; + /* Get Fuart closer to Fref */ fuart *= rounddown_pow_of_two(fref / fuart); -- 2.50.1