[sudeep-holla:for-next/scmi 22/22] drivers/powercap/arm_scmi_powercap.c:429 scmi_powercap_probe() warn: unsigned 'pr->num_zones' is never less than zero.

[kernel test robot]

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/sudeep.holla/linux.git for-next/scmi
head:   31afdd34f2b9e1f33018baa4f279e2b2a91f5afa
commit: 31afdd34f2b9e1f33018baa4f279e2b2a91f5afa [22/22] powercap: arm_scmi: Add SCMI powercap based driver
config: microblaze-randconfig-m031-20220706 (https://download.01.org/0day-ci/archive/20220710/202207101807.UYiCXGqy-lkp@xxxxxxxxx/config)
compiler: microblaze-linux-gcc (GCC) 11.3.0

If you fix the issue, kindly add following tag where applicable
Reported-by: kernel test robot <lkp@xxxxxxxxx>

smatch warnings:
drivers/powercap/arm_scmi_powercap.c:429 scmi_powercap_probe() warn: unsigned 'pr->num_zones' is never less than zero.
drivers/powercap/arm_scmi_powercap.c:494 scmi_powercap_probe() error: uninitialized symbol 'ret'.

vim +429 drivers/powercap/arm_scmi_powercap.c

   406	
   407	static int scmi_powercap_probe(struct scmi_device *sdev)
   408	{
   409		int ret, i;
   410		struct scmi_powercap_root *pr;
   411		struct scmi_powercap_zone *spz;
   412		struct scmi_protocol_handle *ph;
   413		struct device *dev = &sdev->dev;
   414		const struct scmi_handle *handle = sdev->handle;
   415	
   416		if (!handle)
   417			return -ENODEV;
   418	
   419		powercap_ops = handle->devm_protocol_get(sdev, SCMI_PROTOCOL_POWERCAP,
   420							 &ph);
   421		if (IS_ERR(powercap_ops))
   422			return PTR_ERR(powercap_ops);
   423	
   424		pr = devm_kzalloc(dev, sizeof(*pr), GFP_KERNEL);
   425		if (!pr)
   426			return -ENOMEM;
   427	
   428		pr->num_zones = powercap_ops->num_domains_get(ph);
 > 429		if (pr->num_zones < 0) {
   430			dev_err(dev, "number of powercap domains not found\n");
   431			return pr->num_zones;
   432		}
   433	
   434		pr->spzones = devm_kcalloc(dev, pr->num_zones,
   435					   sizeof(*pr->spzones), GFP_KERNEL);
   436		if (!pr->spzones)
   437			return -ENOMEM;
   438	
   439		/* Allocate for worst possible scenario of maximum tree height. */
   440		pr->registered_zones = devm_kcalloc(dev, pr->num_zones,
   441						    sizeof(*pr->registered_zones),
   442						    GFP_KERNEL);
   443		if (!pr->registered_zones)
   444			return -ENOMEM;
   445	
   446		for (i = 0, spz = pr->spzones; i < pr->num_zones; i++, spz++) {
   447			/*
   448			 * Powercap domains are validate by the protocol layer, i.e.
   449			 * when only non-NULL domains are returned here, whose
   450			 * parent_id is assured to point to another valid domain.
   451			 */
   452			spz->info = powercap_ops->info_get(ph, i);
   453	
   454			spz->dev = dev;
   455			spz->ph = ph;
   456			spz->spzones = pr->spzones;
   457			INIT_LIST_HEAD(&spz->node);
   458			INIT_LIST_HEAD(&pr->registered_zones[i]);
   459	
   460			/*
   461			 * Forcibly skip powercap domains using an abstract scale.
   462			 * Note that only leaves domains can be skipped, so this could
   463			 * lead later to a global failure.
   464			 */
   465			if (!spz->info->powercap_scale_uw &&
   466			    !spz->info->powercap_scale_mw) {
   467				dev_warn(dev,
   468					 "Abstract power scale not supported. Skip %s.\n",
   469					 spz->info->name);
   470				spz->info = NULL;
   471				continue;
   472			}
   473		}
   474	
   475		/*
   476		 * Scan array of retrieved SCMI powercap domains and register them
   477		 * recursively starting from the root domains.
   478		 */
   479		for (i = 0, spz = pr->spzones; i < pr->num_zones; i++, spz++) {
   480			ret = scmi_powercap_register_zone(pr, spz);
   481			if (ret) {
   482				dev_err(dev,
   483					"Failed to register powercap zone %s - ret:%d\n",
   484					spz->info->name, ret);
   485				scmi_powercap_unregister_all_zones(pr);
   486				return ret;
   487			}
   488		}
   489	
   490		dev_set_drvdata(dev, pr);
   491	
   492		dev_info(dev, "Registered %d SCMI Powercap domains !\n", pr->num_zones);
   493	
 > 494		return ret;
   495	}
   496	

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