drivers/net/phy/micrel.c:2613 lan8814_ptp_probe_once() warn: passing zero to 'PTR_ERR'

[Dan Carpenter <dan.carpenter@oracle.com>]

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head:   b047602d579b4fb028128a525f056bbdc890e7f0
commit: ece19502834d84ece2e056db28257ca2aa6e4d48 net: phy: micrel: 1588 support for LAN8814 phy
config: openrisc-randconfig-m031-20220712 (https://download.01.org/0day-ci/archive/20220713/202207132330.qoXbH2DO-lkp@intel.com/config)
compiler: or1k-linux-gcc (GCC) 11.3.0

If you fix the issue, kindly add following tag where applicable
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>

New smatch warnings:
drivers/net/phy/micrel.c:2613 lan8814_ptp_probe_once() warn: passing zero to 'PTR_ERR'

vim +/PTR_ERR +2613 drivers/net/phy/micrel.c

ece19502834d84 Divya Koppera 2022-03-04  2589  static int lan8814_ptp_probe_once(struct phy_device *phydev)
ece19502834d84 Divya Koppera 2022-03-04  2590  {
ece19502834d84 Divya Koppera 2022-03-04  2591  	struct lan8814_shared_priv *shared = phydev->shared->priv;
ece19502834d84 Divya Koppera 2022-03-04  2592  
ece19502834d84 Divya Koppera 2022-03-04  2593  	/* Initialise shared lock for clock*/
ece19502834d84 Divya Koppera 2022-03-04  2594  	mutex_init(&shared->shared_lock);
ece19502834d84 Divya Koppera 2022-03-04  2595  
ece19502834d84 Divya Koppera 2022-03-04  2596  	shared->ptp_clock_info.owner = THIS_MODULE;
ece19502834d84 Divya Koppera 2022-03-04  2597  	snprintf(shared->ptp_clock_info.name, 30, "%s", phydev->drv->name);
ece19502834d84 Divya Koppera 2022-03-04  2598  	shared->ptp_clock_info.max_adj = 31249999;
ece19502834d84 Divya Koppera 2022-03-04  2599  	shared->ptp_clock_info.n_alarm = 0;
ece19502834d84 Divya Koppera 2022-03-04  2600  	shared->ptp_clock_info.n_ext_ts = 0;
ece19502834d84 Divya Koppera 2022-03-04  2601  	shared->ptp_clock_info.n_pins = 0;
ece19502834d84 Divya Koppera 2022-03-04  2602  	shared->ptp_clock_info.pps = 0;
ece19502834d84 Divya Koppera 2022-03-04  2603  	shared->ptp_clock_info.pin_config = NULL;
ece19502834d84 Divya Koppera 2022-03-04  2604  	shared->ptp_clock_info.adjfine = lan8814_ptpci_adjfine;
ece19502834d84 Divya Koppera 2022-03-04  2605  	shared->ptp_clock_info.adjtime = lan8814_ptpci_adjtime;
ece19502834d84 Divya Koppera 2022-03-04  2606  	shared->ptp_clock_info.gettime64 = lan8814_ptpci_gettime64;
ece19502834d84 Divya Koppera 2022-03-04  2607  	shared->ptp_clock_info.settime64 = lan8814_ptpci_settime64;
ece19502834d84 Divya Koppera 2022-03-04  2608  	shared->ptp_clock_info.getcrosststamp = NULL;
ece19502834d84 Divya Koppera 2022-03-04  2609  
ece19502834d84 Divya Koppera 2022-03-04  2610  	shared->ptp_clock = ptp_clock_register(&shared->ptp_clock_info,
ece19502834d84 Divya Koppera 2022-03-04  2611  					       &phydev->mdio.dev);
ece19502834d84 Divya Koppera 2022-03-04  2612  	if (IS_ERR_OR_NULL(shared->ptp_clock)) {

This code isn't right.  It should be:

	if (IS_ERR((shared->ptp_clock))) {

If ptp_clock_register() returns NULL then it means that it was
deliberately disabled in the .config.  Ideally the driver could just
accept a NULL and continue to boot if that's what the user has asked
for.  However if that's not a valid option then just add a depend to the
Kconfig file.  The Kconfig stuff around CONFIG_PTP_1588_CLOCK is
slightly complicated and you might want to add a CONFIG_COMPILE_TEST
etc.

But what we don't want is what this code does which is allow the driver
to be compiled in such a way that it can never be used.

ece19502834d84 Divya Koppera 2022-03-04 @2613  		phydev_err(phydev, "ptp_clock_register failed %lu\n",
ece19502834d84 Divya Koppera 2022-03-04  2614  			   PTR_ERR(shared->ptp_clock));
ece19502834d84 Divya Koppera 2022-03-04  2615  		return -EINVAL;
ece19502834d84 Divya Koppera 2022-03-04  2616  	}
ece19502834d84 Divya Koppera 2022-03-04  2617  
ece19502834d84 Divya Koppera 2022-03-04  2618  	phydev_dbg(phydev, "successfully registered ptp clock\n");
ece19502834d84 Divya Koppera 2022-03-04  2619  
ece19502834d84 Divya Koppera 2022-03-04  2620  	shared->phydev = phydev;
ece19502834d84 Divya Koppera 2022-03-04  2621  
ece19502834d84 Divya Koppera 2022-03-04  2622  	/* The EP.4 is shared between all the PHYs in the package and also it
ece19502834d84 Divya Koppera 2022-03-04  2623  	 * can be accessed by any of the PHYs
ece19502834d84 Divya Koppera 2022-03-04  2624  	 */
ece19502834d84 Divya Koppera 2022-03-04  2625  	lanphy_write_page_reg(phydev, 4, LTC_HARD_RESET, LTC_HARD_RESET_);
ece19502834d84 Divya Koppera 2022-03-04  2626  	lanphy_write_page_reg(phydev, 4, PTP_OPERATING_MODE,
ece19502834d84 Divya Koppera 2022-03-04  2627  			      PTP_OPERATING_MODE_STANDALONE_);
ece19502834d84 Divya Koppera 2022-03-04  2628  
ece19502834d84 Divya Koppera 2022-03-04  2629  	return 0;
ece19502834d84 Divya Koppera 2022-03-04  2630  }

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