[PATCH v2] riscv: Skip riscv_cpu_setup() when CPU driver is disabled

[Michal Simek]

Hi Rick, cc: Tom,

On 5/11/26 10:31, Michal Simek wrote:
> Building on commit c64fc632a86a ("riscv: cpu: Use CONFIG_IS_ENABLED(CPU)
> instead of plain ifdef"), add an early return in riscv_cpu_setup() when
> CONFIG_CPU is not enabled. This allows platforms to save code space in
> SPL by disabling CONFIG_SPL_CPU.
> 
> Without this patch, building U-Boot with CONFIG_CPU=n and CONFIG_EVENT=y
> is broken: riscv_cpu_setup() is registered as an EVT_DM_POST_INIT_F event
> spy, and when the CPU uclass is unavailable uclass_find_first_device()
> returns no device, so the function returns -ENODEV. That in turn makes
> event_notify_null() in dm_init_and_scan() fail and triggers a boot hang
> ("initcall initf_dm() failed"). Returning 0 early avoids that failure.
> 
> The compiler's dead-code elimination combined with --gc-sections
> removes the unreachable code and all associated static data,
> achieving significant size reduction without preprocessor guards:
> 
>    spl/u-boot-spl:all -4332 spl/u-boot-spl:rodata -2872
>    spl/u-boot-spl:text -1460
> 
> Signed-off-by: Michal Simek <michal.simek at amd.com>
> Reviewed-by: Yao Zi <me at ziyao.cc>
> ---
> 
> Changes in v2:
> - extend commit message
> 
>   arch/riscv/cpu/cpu.c | 3 +++
>   1 file changed, 3 insertions(+)
> 
> diff --git a/arch/riscv/cpu/cpu.c b/arch/riscv/cpu/cpu.c
> index bbadd0c9a469..3bec7c7cb6d0 100644
> --- a/arch/riscv/cpu/cpu.c
> +++ b/arch/riscv/cpu/cpu.c
> @@ -638,6 +638,9 @@ int riscv_cpu_setup(void)
>   	const char *isa, **exts;
>   	struct udevice *dev;
>   
> +	if (!CONFIG_IS_ENABLED(CPU))
> +		return 0;
> +
>   	uclass_find_first_device(UCLASS_CPU, &dev);
>   	if (!dev) {
>   		debug("unable to find the RISC-V cpu device\n");

Rick: Can you apply this patch?

Thanks,
Michal