[PATCH] powerpc/powernv: Return for invalid IMC domain

[Michael Ellerman]

Anju T Sudhakar <anju at linux.vnet.ibm.com> writes:
> Currently init_imc_pmu() can be failed either because
> an IMC unit with invalid domain(i.e an IMC node not
> supported by the kernel) is attempted a pmu-registration
> or something went wrong while registering a valid IMC unit.
> In both the cases kernel provides a 'Registration failed'
> error message.
>
> Example:
> Log message, when trace-imc node is not supported by the kernel, and the
> skiboot supports trace-imc node.
>
> So for kernel, trace-imc node is now an unknown domain.
>
> [    1.731870] nest_phb5_imc performance monitor hardware support registered
> [    1.731944] nest_powerbus0_imc performance monitor hardware support registered
> [    1.734458] thread_imc performance monitor hardware support registered
> [    1.734460] IMC Unknown Device type
> [    1.734462] IMC PMU (null) Register failed
> [    1.734558] nest_xlink0_imc performance monitor hardware support registered
> [    1.734614] nest_xlink1_imc performance monitor hardware support registered
> [    1.734670] nest_xlink2_imc performance monitor hardware support registered
> [    1.747043] Initialise system trusted keyrings
> [    1.747054] Key type blacklist registered
>
>
> To avoid ambiguity on the error message, return for invalid domain
> before attempting a pmu registration. 

What do we print once the patch is applied?

cheers

> Fixes: 8f95faaac56c1 (`powerpc/powernv: Detect and create IMC device`)
> Reported-by: Pavaman Subramaniyam <pavsubra at in.ibm.com>
> Signed-off-by: Anju T Sudhakar <anju at linux.vnet.ibm.com>
> ---
>  arch/powerpc/platforms/powernv/opal-imc.c | 4 ++++
>  1 file changed, 4 insertions(+)
>
> diff --git a/arch/powerpc/platforms/powernv/opal-imc.c b/arch/powerpc/platforms/powernv/opal-imc.c
> index 58a0794..4e8b0e1 100644
> --- a/arch/powerpc/platforms/powernv/opal-imc.c
> +++ b/arch/powerpc/platforms/powernv/opal-imc.c
> @@ -161,6 +161,10 @@ static int imc_pmu_create(struct device_node *parent, int pmu_index, int domain)
>  	struct imc_pmu *pmu_ptr;
>  	u32 offset;
>  
> +	/* Return for unknown domain */
> +	if (domain < 0)
> +		return -EINVAL;
> +
>  	/* memory for pmu */
>  	pmu_ptr = kzalloc(sizeof(*pmu_ptr), GFP_KERNEL);
>  	if (!pmu_ptr)
> -- 
> 1.8.3.1