Re: [PATCH v5 net-next 2/8] sfc: add devlink info support for ef100

[Jiri Pirko <jiri@resnulli.us>]

Tue, Feb 07, 2023 at 03:42:45PM CET, alejandro.lucero-palau@amd.com wrote:
>
>On 2/2/23 11:58, Jiri Pirko wrote:
>> Thu, Feb 02, 2023 at 12:14:17PM CET, alejandro.lucero-palau@amd.com wrote:
>>> From: Alejandro Lucero <alejandro.lucero-palau@amd.com>
>>>
>>> Support for devlink info command.
>> You are quite brief for couple hundred line patch. Care to shed some
>> more details for the reader? Also, use imperative mood (applies to the
>> rest of the pathes)
>>
>> [...]
>>
>
>OK. I'll be more talkative and imperative here.
>
>>> +static int efx_devlink_info_get(struct devlink *devlink,
>>> +				struct devlink_info_req *req,
>>> +				struct netlink_ext_ack *extack)
>>> +{
>>> +	struct efx_devlink *devlink_private = devlink_priv(devlink);
>>> +	struct efx_nic *efx = devlink_private->efx;
>>> +	char msg[NETLINK_MAX_FMTMSG_LEN];
>>> +	int errors_reported = 0;
>>> +	int rc;
>>> +
>>> +	/* Several different MCDI commands are used. We report first error
>>> +	 * through extack along with total number of errors. Specific error
>>> +	 * information via system messages.
>>> +	 */
>>> +	rc = efx_devlink_info_board_cfg(efx, req);
>>> +	if (rc) {
>>> +		sprintf(msg, "Getting board info failed");
>>> +		errors_reported++;
>>> +	}
>>> +	rc = efx_devlink_info_stored_versions(efx, req);
>>> +	if (rc) {
>>> +		if (!errors_reported)
>>> +			sprintf(msg, "Getting stored versions failed");
>>> +		errors_reported += rc;
>>> +	}
>>> +	rc = efx_devlink_info_running_versions(efx, req);
>>> +	if (rc) {
>>> +		if (!errors_reported)
>>> +			sprintf(msg, "Getting board info failed");
>>> +		errors_reported++;
>>
>> Under which circumstances any of the errors above happen? Is it a common
>> thing? Or is it result of some fatal event?
>
>They are not common at all. If any of those happen, it is a bad sign, 
>and it is more than likely there are more than one because something is 
>not working properly. That is the reason I only report first error found 
>plus the total number of errors detected.
>
>
>>
>> You treat it like it is quite common, which seems very odd to me.
>> If they are rare, just return error right away to the caller.
>
>Well, that is done now. And as I say, I'm not reporting all but just the 
>first one, mainly because the buffer limitation with NETLINK_MAX_FMTMSG_LEN.
>
>If errors trigger, a more complete information will appear in system 
>messages, so that is the reason with:
>
>+               NL_SET_ERR_MSG_FMT(extack,
>+                                  "%s. %d total errors. Check system messages",
>+                                  msg, errors_reported);
>
>I guess you are concerned with the extack report being overwhelmed, but 
>I do not think that is the case.

No, I'm wondering why you just don't put error message into exack and
return -ESOMEERROR right away.

>
>>
>>
>>> +	}
>>> +
>>> +	if (errors_reported)
>>> +		NL_SET_ERR_MSG_FMT(extack,
>>> +				   "%s. %d total errors. Check system messages",
>>> +				   msg, errors_reported);
>>> +	return 0;
>>> +}
>>> +
>>> static const struct devlink_ops sfc_devlink_ops = {
>>> +	.info_get			= efx_devlink_info_get,
>>> };
>> [...]