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SubjectRe: [PATCH 1/4] arm: pxa: change clocks init sequence
Date
Quoting Robert Jarzmik (2014-12-27 05:55:25)
> Since pxa clocks were ported to the clock framework, an ordering issue
> appears between clocks and clocksource initialization. As a consequence,
> the pxa timer clock cannot be acquired in pxa_timer, and is disabled by
> clock framework because it is "unused".
>
> The ordering issue is that in the kernel boot sequence :
> start_kernel()
> ...
> time_init()
> -> pxa_timer()
> -> here the clocksource is initialized
> ...
> rest_init()
> kernel_init()
> initcalls
> -> here the clocks are initialized
>
> In the current sequence, the clocks are initialized way after pxa_timer,
> which cannot acquire the OSTIMER0 clock.
>
> To solve this issue, the clocks initialization is moved to pxa_timer(),
> so that clocks are initialized before clocksource for non device-tree.
> For device-tree, the standard arm time_init() will take care of the
> ordering.
>
> Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr>

Reviewed-by: Michael Turquette <mturquette@linaro.org>

> ---
> arch/arm/mach-pxa/generic.c | 4 ++++
> arch/arm/mach-pxa/generic.h | 2 ++
> drivers/clk/pxa/clk-pxa27x.c | 3 +--
> 3 files changed, 7 insertions(+), 2 deletions(-)
>
> diff --git a/arch/arm/mach-pxa/generic.c b/arch/arm/mach-pxa/generic.c
> index 04b013f..d988c53 100644
> --- a/arch/arm/mach-pxa/generic.c
> +++ b/arch/arm/mach-pxa/generic.c
> @@ -63,6 +63,10 @@ EXPORT_SYMBOL(get_clock_tick_rate);
> */
> void __init pxa_timer_init(void)
> {
> + if (cpu_is_pxa25x())
> + pxa25x_clocks_init();
> + if (cpu_is_pxa27x())
> + pxa27x_clocks_init();
> pxa_timer_nodt_init(IRQ_OST0, io_p2v(0x40a00000),
> get_clock_tick_rate());
> }
> diff --git a/arch/arm/mach-pxa/generic.h b/arch/arm/mach-pxa/generic.h
> index 7a9fa1a..149087c 100644
> --- a/arch/arm/mach-pxa/generic.h
> +++ b/arch/arm/mach-pxa/generic.h
> @@ -26,11 +26,13 @@ extern void pxa_timer_init(void);
> #define ARRAY_AND_SIZE(x) (x), ARRAY_SIZE(x)
>
> #define pxa25x_handle_irq icip_handle_irq
> +extern int __init pxa25x_clocks_init(void);
> extern void __init pxa25x_init_irq(void);
> extern void __init pxa25x_map_io(void);
> extern void __init pxa26x_init_irq(void);
>
> #define pxa27x_handle_irq ichp_handle_irq
> +extern int __init pxa27x_clocks_init(void);
> extern void __init pxa27x_dt_init_irq(void);
> extern unsigned pxa27x_get_clk_frequency_khz(int);
> extern void __init pxa27x_init_irq(void);
> diff --git a/drivers/clk/pxa/clk-pxa27x.c b/drivers/clk/pxa/clk-pxa27x.c
> index 5f9b54b..2b8343a 100644
> --- a/drivers/clk/pxa/clk-pxa27x.c
> +++ b/drivers/clk/pxa/clk-pxa27x.c
> @@ -362,12 +362,11 @@ static void __init pxa27x_base_clocks_init(void)
> clk_register_clk_pxa27x_lcd_base();
> }
>
> -static int __init pxa27x_clocks_init(void)
> +int __init pxa27x_clocks_init(void)
> {
> pxa27x_base_clocks_init();
> return clk_pxa_cken_init(pxa27x_clocks, ARRAY_SIZE(pxa27x_clocks));
> }
> -postcore_initcall(pxa27x_clocks_init);
>
> static void __init pxa27x_dt_clocks_init(struct device_node *np)
> {
> --
> 2.1.0
>


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