Re: [PATCH v2] ipmi:si: Add async init to ipmi_si

[Corey Minyard <corey@minyard.net>]

On Fri, Jul 03, 2026 at 05:09:55PM +0200, Michal Clapinski wrote:
> Added a new config option to allow offloading individual calls to
> try_smi_init(). Saves 100ms on my system.

This looks good.  In a few releases I may change the default to y, if I
can remember it by then :-).

It's in my next tree.

-corey

> 
> Signed-off-by: Michal Clapinski <mclapinski@google.com>
> ---
> v2:
> - instead of offloading the whole init function, offload just the
>   individual calls to try_smi_init()
> 
> I didn't implement the periodic retry feature that was talked about
> under v1 due to my lack of expertise. LMK if this is a deal-breaker.
> ---
>  drivers/char/ipmi/Kconfig        |  9 +++++++++
>  drivers/char/ipmi/ipmi_si_intf.c | 32 ++++++++++++++++++++++++++++----
>  2 files changed, 37 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/char/ipmi/Kconfig b/drivers/char/ipmi/Kconfig
> index 669f76000197..c8fa445c1c17 100644
> --- a/drivers/char/ipmi/Kconfig
> +++ b/drivers/char/ipmi/Kconfig
> @@ -67,6 +67,15 @@ config IPMI_SI
>  	  Currently, only KCS and SMIC are supported.  If
>  	  you are using IPMI, you should probably say "y" here.
>  
> +config IPMI_SI_ASYNC_INIT
> +	bool 'Asynchronous initialization of IPMI System Interface'
> +	depends on IPMI_SI
> +	default n
> +	help
> +	  Offloads invidual SMI inits. It speeds up the boot time.
> +	  It also introduces a very small risk that something else might fail
> +	  if it depends on synchronous IPMI init.
> +
>  config IPMI_SSIF
>  	tristate 'IPMI SMBus handler (SSIF)'
>  	depends on I2C
> diff --git a/drivers/char/ipmi/ipmi_si_intf.c b/drivers/char/ipmi/ipmi_si_intf.c
> index 9a9d12be9bf7..504d5b8636ba 100644
> --- a/drivers/char/ipmi/ipmi_si_intf.c
> +++ b/drivers/char/ipmi/ipmi_si_intf.c
> @@ -39,6 +39,7 @@
>  #include <linux/rcupdate.h>
>  #include <linux/ipmi.h>
>  #include <linux/ipmi_smi.h>
> +#include <linux/async.h>
>  #include "ipmi_si.h"
>  #include "ipmi_si_sm.h"
>  #include <linux/string.h>
> @@ -2174,6 +2175,17 @@ static bool __init ipmi_smi_info_same(struct smi_info *e1, struct smi_info *e2)
>  		e1->io.addr_data == e2->io.addr_data);
>  }
>  
> +static ASYNC_DOMAIN_EXCLUSIVE(ipmi_si_async_domain);
> +
> +static void __init async_try_smi_init(void *data, async_cookie_t cookie)
> +{
> +	struct smi_info *smi = data;
> +
> +	mutex_lock(&smi_infos_lock);
> +	try_smi_init(smi);
> +	mutex_unlock(&smi_infos_lock);
> +}
> +
>  static int __init init_ipmi_si(void)
>  {
>  	struct smi_info *e, *e2;
> @@ -2219,8 +2231,13 @@ static int __init init_ipmi_si(void)
>  				break;
>  			}
>  		}
> -		if (!dup)
> -			try_smi_init(e);
> +		if (!dup) {
> +			if (IS_ENABLED(CONFIG_IPMI_SI_ASYNC_INIT))
> +				async_schedule_domain(async_try_smi_init, e,
> +						      &ipmi_si_async_domain);
> +			else
> +				try_smi_init(e);
> +		}
>  	}
>  
>  	/*
> @@ -2253,8 +2270,13 @@ static int __init init_ipmi_si(void)
>  				break;
>  			}
>  		}
> -		if (!dup)
> -			try_smi_init(e);
> +		if (!dup) {
> +			if (IS_ENABLED(CONFIG_IPMI_SI_ASYNC_INIT))
> +				async_schedule_domain(async_try_smi_init, e,
> +						      &ipmi_si_async_domain);
> +			else
> +				try_smi_init(e);
> +		}
>  	}
>  
>  	initialized = true;
> @@ -2401,6 +2423,8 @@ static void cleanup_ipmi_si(void)
>  	if (!initialized)
>  		return;
>  
> +	async_synchronize_full_domain(&ipmi_si_async_domain);
> +
>  	ipmi_si_pci_shutdown();
>  
>  	ipmi_si_ls2k_shutdown();
> -- 
> 2.55.0.795.g602f6c329a-goog
>