[RFC PATCH] ARM: smp_twd: Fix twd_get_clock() to get clock from dts or clock framework

[Linus Walleij]

On Sat, Aug 10, 2013 at 12:35 AM,  <dinguyen at altera.com> wrote:

> From: Dinh Nguyen <dinguyen at altera.com>
>
> Some platforms have a clock for the smp_twd that goes through a fixed
> divider. Registering this smp_twd clocks is done by calling
> clk_register_fixed_factor().
>
> Fix up twd_get_clock() so that it can get the clock from the device
> tree node or clk_register_fixed_factor().
>
> Signed-off-by: Dinh Nguyen <dinguyen at altera.com>
(...)
>         if (np)
>                 twd_clk = of_clk_get(np, 0);
> -       else
> +
> +       /* Some platforms do not register the smp_twd clock in the device */
> +       /* node of the twd timer. */
> +       if (IS_ERR(twd_clk))
>                 twd_clk = clk_get_sys("smp_twd", NULL);

NACK.

The patch commit message and the patch itself does not match.
This has nothing to do with using fixed factor or whatever.

What it wants to do is use clk_get_sys() in case of_clk_get() fails,
so DT clocks take precedence.

But this patch is buggy. If you have only platform data, and boot
without device tree, np will be NULL, and twd_clk will also be
NULL and thus clk_get_sys() will not execute and the system
is bugged up.

Yours,
Linus Walleij