[Xen-changelog] [xen master] pl011: early_panic if baud rate not set in hardware

[patchbot@xxxxxxx]

commit 2050ad703c65ed997f1328af702054d1960fb168
Author:     Ian Campbell <ian.campbell@xxxxxxxxxx>
AuthorDate: Thu Aug 22 17:01:59 2013 +0100
Commit:     Ian Campbell <ian.campbell@xxxxxxxxxx>
CommitDate: Tue Aug 27 14:35:44 2013 +0100

    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 <ian.campbell@xxxxxxxxxx>
    Acked-by: Julien Grall <julien.grall@xxxxxxxxxx>
---
 xen/drivers/char/pl011.c |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)

diff --git a/xen/drivers/char/pl011.c b/xen/drivers/char/pl011.c
index e4bd702..3ea0d41 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. */
--
generated by git-patchbot for /home/xen/git/xen.git#master

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