Re: [PATCH] [RFC] ARM: shmobile: koelsch-reference: Work around core clock issues

[Laurent Pinchart <laurent.pinchart@ideasonboard.com>]

Hi Geert,

Thank you for the patch.

On Thursday 13 March 2014 15:29:30 Geert Uytterhoeven wrote:
> From: Geert Uytterhoeven <geert+renesas@linux-m68k.org>
> 
> Due to issues with runtime PM clock management, clocks not explicitly
> managed by their drivers may not be enabled at all, or be inadvertently
> disabled by the clk_disable_unused() late initcall.
> 
> Until this is fixed, add a temporary workaround, calling
> shmobile_clk_workaround() with enable = true.
> 
> For now this enables the clocks for: ether, i2c2, msiof0, qspi_mod, and
> thermal. More clocks can be added if needed.

This should do the job, but as you mentioned, it's a crude hack. As we're 
targeting v3.16, is there a chance we could fix the problem properly instead ?

> Signed-off-by: Geert Uytterhoeven <geert+renesas@linux-m68k.org>
> ---
> Tested with and without CONFIG_PM_RUNTIME
> 
>  arch/arm/mach-shmobile/board-koelsch-reference.c |   12 ++++++++++++
>  1 file changed, 12 insertions(+)
> 
> diff --git a/arch/arm/mach-shmobile/board-koelsch-reference.c
> b/arch/arm/mach-shmobile/board-koelsch-reference.c index
> a760f7f19bc9..040c6b99cde2 100644
> --- a/arch/arm/mach-shmobile/board-koelsch-reference.c
> +++ b/arch/arm/mach-shmobile/board-koelsch-reference.c
> @@ -107,9 +107,21 @@ static const struct clk_name clk_names[] = {
>  	{ "lvds0", "lvds.0", "rcar-du-r8a7791" },
>  };
> 
> +/*
> + * This is a really crude hack to work around core platform clock issues
> + */
> +static const struct clk_name clk_enables[] = {
> +	{ "ether", NULL, "ee700000.ethernet" },
> +	{ "i2c2", NULL, "e6530000.i2c" },
> +	{ "msiof0", NULL, "e6e20000.spi" },
> +	{ "qspi_mod", NULL, "e6b10000.spi" },
> +	{ "thermal", NULL, "e61f0000.thermal" },
> +};
> +
>  static void __init koelsch_add_standard_devices(void)
>  {
>  	shmobile_clk_workaround(clk_names, ARRAY_SIZE(clk_names), false);
> +	shmobile_clk_workaround(clk_enables, ARRAY_SIZE(clk_enables), true);
>  	r8a7791_add_dt_devices();
>  	of_platform_populate(NULL, of_default_bus_match_table, NULL, NULL);

-- 
Regards,

Laurent Pinchart