[PATCH 1/2] rockchip: misc: Only assign serial# variable if unset

[Heiko Stuebner <heiko.stuebner@theobroma-systems.com>]

Hi Paul,

On 03.12.19 16:46, Paul Kocialkowski wrote:
> The serial# environment variable is a read-only special variable, that
> can only be set once. As a result, if the environment was saved to a
> persistent storage location, attempting to set it again in
> rockchip_cpuid_set will fail and halt the boot with the following error:
>
> Solve this by checking whether the variable is already set before.
>
> Signed-off-by: Paul Kocialkowski <paul.kocialkowski@bootlin.com>

it looks like we're fixing the same problems a lot. Yesterday I
also got a patch from Miquel about the px30 iommu clocks ;-) .

Here it's the same as "rockchip: misc: protect serial# from getting 
overwritten"
from november 29 ;-)

Heiko

> ---
>   arch/arm/mach-rockchip/misc.c | 14 +++++++++-----
>   1 file changed, 9 insertions(+), 5 deletions(-)
>
> diff --git a/arch/arm/mach-rockchip/misc.c b/arch/arm/mach-rockchip/misc.c
> index bed4317f7ece..a0c6a1c0b266 100644
> --- a/arch/arm/mach-rockchip/misc.c
> +++ b/arch/arm/mach-rockchip/misc.c
> @@ -108,12 +108,16 @@ int rockchip_cpuid_set(const u8 *cpuid, const u32 cpuid_length)
>   		high[i] = cpuid[i << 1];
>   	}
>   
> -	serialno = crc32_no_comp(0, low, 8);
> -	serialno |= (u64)crc32_no_comp(serialno, high, 8) << 32;
> -	snprintf(serialno_str, sizeof(serialno_str), "%016llx", serialno);
> -
>   	env_set("cpuid#", cpuid_str);
> -	env_set("serial#", serialno_str);
> +
> +	if (!env_get("serial#")) {
> +		serialno = crc32_no_comp(0, low, 8);
> +		serialno |= (u64)crc32_no_comp(serialno, high, 8) << 32;
> +		snprintf(serialno_str, sizeof(serialno_str), "%016llx",
> +			 serialno);
> +
> +		env_set("serial#", serialno_str);
> +	}
>   
>   	return 0;
>   }