Subject: Re: [PATCH v2 01/17] firmware: arm_scmi: Define a common SCMI_MAX_PROTOCOLS value

From: Jonathan Cameron <[email-masked]>
Date: Mon, 19 Jan 2026 11:18:27 +0000

On Wed, 14 Jan 2026 11:46:05 +0000
Cristian Marussi <[email-masked]> wrote:

> Add a common definition of SCMI_MAX_PROTOCOLS and use it all over the
> SCMI stack.
> 
> Signed-off-by: Cristian Marussi <[email-masked]>
Hi Cristian,

Mention the introduction of SCMI_PROTOCOL_LAST in the patch description
and probably say why it takes that value (which is much less than
the SCMI_MAX_PROTOCOLS value).

Jonathan

> ---
>  drivers/firmware/arm_scmi/notify.c | 4 +---
>  include/linux/scmi_protocol.h      | 3 +++
>  2 files changed, 4 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/firmware/arm_scmi/notify.c b/drivers/firmware/arm_scmi/notify.c
> index dee9f238f6fd..78e9e27dc9ec 100644
> --- a/drivers/firmware/arm_scmi/notify.c
> +++ b/drivers/firmware/arm_scmi/notify.c
> @@ -94,8 +94,6 @@
>  #include "common.h"
>  #include "notify.h"
>  
> -#define SCMI_MAX_PROTO		256
> -
>  #define PROTO_ID_MASK		GENMASK(31, 24)
>  #define EVT_ID_MASK		GENMASK(23, 16)
>  #define SRC_ID_MASK		GENMASK(15, 0)
> @@ -1673,7 +1671,7 @@ int scmi_notification_init(struct scmi_handle *handle)
>  	ni->gid = gid;
>  	ni->handle = handle;
>  
> -	ni->registered_protocols = devm_kcalloc(handle->dev, SCMI_MAX_PROTO,
> +	ni->registered_protocols = devm_kcalloc(handle->dev, SCMI_MAX_PROTOCOLS,
>  						sizeof(char *), GFP_KERNEL);
>  	if (!ni->registered_protocols)
>  		goto err;
> diff --git a/include/linux/scmi_protocol.h b/include/linux/scmi_protocol.h
> index aafaac1496b0..c6efe4f371ac 100644
> --- a/include/linux/scmi_protocol.h
> +++ b/include/linux/scmi_protocol.h
> @@ -926,8 +926,11 @@ enum scmi_std_protocol {
>  	SCMI_PROTOCOL_VOLTAGE = 0x17,
>  	SCMI_PROTOCOL_POWERCAP = 0x18,
>  	SCMI_PROTOCOL_PINCTRL = 0x19,
> +	SCMI_PROTOCOL_LAST = 0x7f,
>  };
>  
> +#define SCMI_MAX_PROTOCOLS	256
> +
>  enum scmi_system_events {
>  	SCMI_SYSTEM_SHUTDOWN,
>  	SCMI_SYSTEM_COLDRESET,