[usb:usb-testing 63/64] drivers/usb/typec/mux.c:167 typec_mux_match() warn: unsigned 'nval' is never less than zero.

[kbuild test robot <lkp@xxxxxxxxx>]

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing
head:   09aa11cfda9d8186046bcd1adcd6498b688114f4
commit: 96a6d031ca9930938bd66d0052fc7ed2b56e3583 [63/64] usb: typec: mux: Find the muxes by also matching against the device node

smatch warnings:
drivers/usb/typec/mux.c:167 typec_mux_match() warn: unsigned 'nval' is never less than zero.

vim +/nval +167 drivers/usb/typec/mux.c

   124	
   125	static void *typec_mux_match(struct device_connection *con, int ep, void *data)
   126	{
   127		const struct typec_altmode_desc *desc = data;
   128		struct typec_mux *mux;
   129		size_t nval;
   130		bool match;
   131		u16 *val;
   132		int i;
   133	
   134		if (!con->fwnode) {
   135			list_for_each_entry(mux, &mux_list, entry)
   136				if (!strcmp(con->endpoint[ep], dev_name(mux->dev)))
   137					return mux;
   138			return ERR_PTR(-EPROBE_DEFER);
   139		}
   140	
   141		/*
   142		 * Check has the identifier already been "consumed". If it
   143		 * has, no need to do any extra connection identification.
   144		 */
   145		match = !con->id;
   146		if (match)
   147			goto find_mux;
   148	
   149		/* Accessory Mode muxes */
   150		if (!desc) {
   151			match = fwnode_property_present(con->fwnode, "accessory");
   152			if (match)
   153				goto find_mux;
   154			return NULL;
   155		}
   156	
   157		/* Alternate Mode muxes */
   158		nval = fwnode_property_read_u16_array(con->fwnode, "svid", NULL, 0);
   159		if (nval <= 0)
   160			return NULL;
   161	
   162		val = kcalloc(nval, sizeof(*val), GFP_KERNEL);
   163		if (!val)
   164			return ERR_PTR(-ENOMEM);
   165	
   166		nval = fwnode_property_read_u16_array(con->fwnode, "svid", val, nval);
 > 167		if (nval < 0) {
   168			kfree(val);
   169			return ERR_PTR(nval);
   170		}
   171	
   172		for (i = 0; i < nval; i++) {
   173			match = val[i] == desc->svid;
   174			if (match) {
   175				kfree(val);
   176				goto find_mux;
   177			}
   178		}
   179		kfree(val);
   180		return NULL;
   181	
   182	find_mux:
   183		list_for_each_entry(mux, &mux_list, entry)
   184			if (dev_fwnode(mux->dev) == con->fwnode)
   185				return mux;
   186	
   187		return match ? ERR_PTR(-EPROBE_DEFER) : NULL;
   188	}
   189	

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