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: firefly_0821_release~176^2~4^2~43^2~20 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=1401ebda89ebf3156984c175209f630e0844f6ce;p=firefly-linux-kernel-4.4.55.git serial: 8250_pci: fix divide error bug if baud rate is 0 commit 6f210c18c1c0f016772c8cd51ae12a02bfb9e7ef upstream. 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") Suggested-by: Andy Shevchenko Reviewed-by: Andy Shevchenko Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/tty/serial/8250/8250_pci.c b/drivers/tty/serial/8250/8250_pci.c index 7cd6f9a90542..c1d4a8fa9be8 100644 --- a/drivers/tty/serial/8250/8250_pci.c +++ b/drivers/tty/serial/8250/8250_pci.c @@ -1401,6 +1401,9 @@ 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);