This is a note to let you know that I've just added the patch titled serial: 8250_pci: fix divide error bug if baud rate is 0 to the 4.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: serial-8250_pci-fix-divide-error-bug-if-baud-rate-is-0.patch and it can be found in the queue-4.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 6f210c18c1c0f016772c8cd51ae12a02bfb9e7ef Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?David=20M=C3=BCller?= <d.mueller@xxxxxxxxx> Date: Wed, 27 Apr 2016 11:58:32 +0200 Subject: serial: 8250_pci: fix divide error bug if baud rate is 0 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: David Müller <d.mueller@xxxxxxxxx> 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 <d.mueller@xxxxxxxxx> Fixes: 21947ba654a6 ("serial: 8250_pci: replace switch-case by formula") Suggested-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx> Reviewed-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/tty/serial/8250/8250_pci.c | 3 +++ 1 file changed, 3 insertions(+) --- 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, str 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); Patches currently in stable-queue which might be from d.mueller@xxxxxxxxx are queue-4.4/serial-8250_pci-fix-divide-error-bug-if-baud-rate-is-0.patch -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html