linux-kernel - Re: [PATCH] ipmi: add retry in try_get_dev

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Message-ID: <20200916140126.GE3674@minyard.net>
Date:   Wed, 16 Sep 2020 09:01:26 -0500
From:   Corey Minyard <minyard@....org>
To:     Xianting Tian <tian.xianting@....com>
Cc:     arnd@...db.de, gregkh@...uxfoundation.org,
        openipmi-developer@...ts.sourceforge.net,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH] ipmi: add retry in try_get_dev_id()

On Wed, Sep 16, 2020 at 02:21:29PM +0800, Xianting Tian wrote:
> Use retry machanism to give device more opportunitys to correctly response
> kernel when we received specific completion codes.
> 
> This is similar to what we done in __get_device_id().

Thanks.  I moved GET_DEVICE_ID_MAX_RETRY to include/linux/ipmi.h since
uapi is for things exported to userspace.  But this is good, it's in my
next tree.

-corey

> 
> Signed-off-by: Xianting Tian <tian.xianting@....com>
> ---
>  drivers/char/ipmi/ipmi_msghandler.c |  2 --
>  drivers/char/ipmi/ipmi_si_intf.c    | 17 +++++++++++++++++
>  include/uapi/linux/ipmi.h           |  2 ++
>  3 files changed, 19 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/char/ipmi/ipmi_msghandler.c b/drivers/char/ipmi/ipmi_msghandler.c
> index b9685093e..75cb7e062 100644
> --- a/drivers/char/ipmi/ipmi_msghandler.c
> +++ b/drivers/char/ipmi/ipmi_msghandler.c
> @@ -62,8 +62,6 @@ enum ipmi_panic_event_op {
>  #define IPMI_PANIC_DEFAULT IPMI_SEND_PANIC_EVENT_NONE
>  #endif
>  
> -#define GET_DEVICE_ID_MAX_RETRY	5
> -
>  static enum ipmi_panic_event_op ipmi_send_panic_event = IPMI_PANIC_DEFAULT;
>  
>  static int panic_op_write_handler(const char *val,
> diff --git a/drivers/char/ipmi/ipmi_si_intf.c b/drivers/char/ipmi/ipmi_si_intf.c
> index 77b8d551a..beeb705f1 100644
> --- a/drivers/char/ipmi/ipmi_si_intf.c
> +++ b/drivers/char/ipmi/ipmi_si_intf.c
> @@ -1316,6 +1316,7 @@ static int try_get_dev_id(struct smi_info *smi_info)
>  	unsigned char         *resp;
>  	unsigned long         resp_len;
>  	int                   rv = 0;
> +	unsigned int          retry_count = 0;
>  
>  	resp = kmalloc(IPMI_MAX_MSG_LENGTH, GFP_KERNEL);
>  	if (!resp)
> @@ -1327,6 +1328,8 @@ static int try_get_dev_id(struct smi_info *smi_info)
>  	 */
>  	msg[0] = IPMI_NETFN_APP_REQUEST << 2;
>  	msg[1] = IPMI_GET_DEVICE_ID_CMD;
> +
> +retry:
>  	smi_info->handlers->start_transaction(smi_info->si_sm, msg, 2);
>  
>  	rv = wait_for_msg_done(smi_info);
> @@ -1339,6 +1342,20 @@ static int try_get_dev_id(struct smi_info *smi_info)
>  	/* Check and record info from the get device id, in case we need it. */
>  	rv = ipmi_demangle_device_id(resp[0] >> 2, resp[1],
>  			resp + 2, resp_len - 2, &smi_info->device_id);
> +	if (rv) {
> +		/* record completion code */
> +		char cc = *(resp + 2);
> +
> +		if ((cc == IPMI_DEVICE_IN_FW_UPDATE_ERR
> +		    || cc == IPMI_DEVICE_IN_INIT_ERR
> +		    || cc == IPMI_NOT_IN_MY_STATE_ERR)
> +		    && ++retry_count <= GET_DEVICE_ID_MAX_RETRY) {
> +			dev_warn(smi_info->io.dev,
> +				"retry to get device id as completion code 0x%x\n",
> +				 cc);
> +			goto retry;
> +		}
> +	}
>  
>  out:
>  	kfree(resp);
> diff --git a/include/uapi/linux/ipmi.h b/include/uapi/linux/ipmi.h
> index 32d148309..bc57f07e3 100644
> --- a/include/uapi/linux/ipmi.h
> +++ b/include/uapi/linux/ipmi.h
> @@ -426,4 +426,6 @@ struct ipmi_timing_parms {
>  #define IPMICTL_GET_MAINTENANCE_MODE_CMD	_IOR(IPMI_IOC_MAGIC, 30, int)
>  #define IPMICTL_SET_MAINTENANCE_MODE_CMD	_IOW(IPMI_IOC_MAGIC, 31, int)
>  
> +#define GET_DEVICE_ID_MAX_RETRY		5
> +
>  #endif /* _UAPI__LINUX_IPMI_H */
> -- 
> 2.17.1
>