From 2050ad703c65ed997f1328af702054d1960fb168 Mon Sep 17 00:00:00 2001 From: Ian Campbell Date: Thu, 22 Aug 2013 17:01:59 +0100 Subject: pl011: early_panic if baud rate not set in hardware Now that the driver defaults to BAUD_AUTO this can happen if the early uart != console or if early printk isn't in use. The following division by zero causes a trap but that uses regular printk and not early_printk, so it is never seen. Signed-off-by: Ian Campbell Acked-by: Julien Grall --- xen/drivers/char/pl011.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'xen/drivers') diff --git a/xen/drivers/char/pl011.c b/xen/drivers/char/pl011.c index e4bd702f3f..3ea0d41f8c 100644 --- a/xen/drivers/char/pl011.c +++ b/xen/drivers/char/pl011.c @@ -104,6 +104,8 @@ static void __init pl011_init_preirq(struct serial_port *port) { /* Baud rate already set: read it out from the divisor latch. */ divisor = (pl011_read(uart, IBRD) << 6) | (pl011_read(uart, FBRD)); + if (!divisor) + early_panic("pl011: No Baud rate configured\n"); uart->baud = (uart->clock_hz << 2) / divisor; } /* This write must follow FBRD and IBRD writes. */ -- cgit v1.2.3