[U-Boot] [PATCH] sunxi: Fix sun5i mbus speed when booting old kernels

[Siarhei Siamashka <siarhei.siamashka@gmail.com>]

On Thu, 19 Feb 2015 14:59:16 +0100
Hans de Goede <hdegoede@redhat.com> wrote:

> Older linux-sunxi-3.4 kernels override our PLL6 setting with 300 MHz,
> halving the mbus frequency, so set it to 300 MHz ourselves and base the
> mbus divider on that.
> 
> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
> ---
>  arch/arm/include/asm/arch-sunxi/clock_sun4i.h | 9 +++++++++
>  1 file changed, 9 insertions(+)
> 
> diff --git a/arch/arm/include/asm/arch-sunxi/clock_sun4i.h b/arch/arm/include/asm/arch-sunxi/clock_sun4i.h
> index d297ed0..c28ee05 100644
> --- a/arch/arm/include/asm/arch-sunxi/clock_sun4i.h
> +++ b/arch/arm/include/asm/arch-sunxi/clock_sun4i.h
> @@ -144,7 +144,16 @@ struct sunxi_ccm_reg {
>  
>  #define PLL1_CFG_DEFAULT	0xa1005000
>  
> +#if defined CONFIG_OLD_SUNXI_KERNEL_COMPAT && defined CONFIG_MACH_SUN5I
> +/*
> + * Older linux-sunxi-3.4 kernels override our PLL6 setting with 300 MHz,
> + * halving the mbus frequency, so set it to 300 MHz ourselves and base the
> + * mbus divider on that.
> + */
> +#define PLL6_CFG_DEFAULT	0xa1009900
> +#else
>  #define PLL6_CFG_DEFAULT	0xa1009911
> +#endif
>  
>  /* nand clock */
>  #define NAND_CLK_SRC_OSC24		0

Are there any good reasons to use 600MHz instead of 300MHz for PLL6 in
the default u-boot build?

Maybe PLL6 can be just set to 300MHz for sun5i in all cases, regardless
of the CONFIG_OLD_SUNXI_KERNEL_COMPAT define?

-- 
Best regards,
Siarhei Siamashka