From mboxrd@z Thu Jan  1 00:00:00 1970
From: Stephen Hemminger <stephen@networkplumber.org>
Subject: Re: [PATCH 05/22] ethdev: introduce device lock
Date: Fri, 15 Jun 2018 09:09:03 -0700
Message-ID: <20180615090903.67198498@xeon-e3>
References: <20180607123849.14439-1-qi.z.zhang@intel.com>
 <20180607123849.14439-6-qi.z.zhang@intel.com>
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Cc: thomas@monjalon.net, anatoly.burakov@intel.com,
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 ferruh.yigit@intel.com, benjamin.h.shelton@intel.com,
 narender.vangati@intel.com
To: Qi Zhang <qi.z.zhang@intel.com>
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On Thu,  7 Jun 2018 20:38:32 +0800
Qi Zhang <qi.z.zhang@intel.com> wrote:

> +/**
> + * Lock an Ethernet Device directly or register a callback function
> + * for condition check at runtime, this help application to prevent
> + * a device be detached unexpectly.
> + * NOTE: Lock a device mutliple times with same parmeter will increase
> + * a ref_count, and coresponding unlock decrease the ref_count, the
> + * device will be unlocked when ref_count reach 0.
> + *
> + * @param port_id
> + *   The port identifier of the Ethernet device.
> + * @param callback
> + *   !NULL the callback function will be added into a pre-detach list,
> + *         it will be invoked when a device is going to be detached. The
> + *         return value will decide if continue detach the device or not.
> + *   NULL  lock the device directly, basically this just regiter a empty
> + *         callback function(dev_is_busy) that return -EBUSY, so we can
> + *         handle the pre-detach check in unified way.
> + * @param user_args
> + *   parameter will be parsed to callback function, only valid when
> + *   callback != NULL.
> + * @return
> + *   0 on success, negative on error.
> + */
> +int rte_eth_dev_lock(uint16_t port_id, rte_eth_dev_lock_callback_t callback,
> +		     void *user_args);

I prefer API's that do one thing with one function.
Why not
	rte_eth_dev_lock(uint16_t port_id);
	rte_eth_dev_ondetach(uint16_t port_id, rte_eth_dev_lock_callback_t callback,
           		     void *user_args);