current-speed property in serial devices causes kernel panic

[Kumar Gala]

On Jun 29, 2007, at 11:26 PM, Timur Tabi wrote:

> I see this code in function of_platform_serial_setup():
>
> static int __devinit of_platform_serial_setup(struct of_device *ofdev,
>                                         int type, struct uart_port  
> *port)
> {
>         struct resource resource;
>         struct device_node *np = ofdev->node;
>         const unsigned int *clk, *spd;
>         int ret;
>
>         memset(port, 0, sizeof *port);
>         spd = of_get_property(np, "current-speed", NULL);
> ...
>         port->custom_divisor = *clk / (16 * (*spd));
>
>         return 0;
> }
>
> There is no check in this code to make sure spd is not null.  And  
> sure enough, in most DTS files, current-speed does not exist.  So  
> whenever this function is called on a node like this, the kernel  
> panics.

I'm wondering why we set port->custom_divisor instead of setting port- 
 >speed. (plus the null check).

- k