From: David Müller Date: Wed, 27 Apr 2016 09:58:32 +0000 (+0200) Subject: serial: 8250_pci: fix divide error bug if baud rate is 0 X-Git-Tag: v4.1.12-92~15^2~151 X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=402661daa9557841addb936fdb9a71b0d45a241c;p=users%2Fjedix%2Flinux-maple.git serial: 8250_pci: fix divide error bug if baud rate is 0 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 --- diff --git a/drivers/tty/serial/8250/8250_pci.c b/drivers/tty/serial/8250/8250_pci.c index 9373cca121d33..9d25198cad96f 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);