On Sat, May 19, 2018 at 02:09:24PM +0300, ilialin@xxxxxxxxxxxxxx wrote: > +static int __init qcom_cpufreq_kryo_driver_init(void) > +{ > + struct device *cpu_dev_silver, *cpu_dev_gold; > + struct opp_table *opp_silver, *opp_gold; > + enum _msm8996_version msm8996_version; > + struct nvmem_cell *speedbin_nvmem; > + struct platform_device *pdev; > + struct device_node *np; > + u8 *speedbin; > + u32 versions; > + size_t len; > + int ret; > + > + cpu_dev_silver = get_cpu_device(SILVER_LEAD); > + if (IS_ERR_OR_NULL(cpu_dev_silver)) > + return PTR_ERR(cpu_dev_silver); > + > + cpu_dev_gold = get_cpu_device(SILVER_LEAD); > + if (IS_ERR_OR_NULL(cpu_dev_gold)) > + return PTR_ERR(cpu_dev_gold); > + > + msm8996_version = qcom_cpufreq_kryo_get_msm_id(); > + if (NUM_OF_MSM8996_VERSIONS == msm8996_version) { > + dev_err(cpu_dev_silver, "Not Snapdragon 820/821!"); > + return -ENODEV; > + } > + > + np = dev_pm_opp_of_get_opp_desc_node(cpu_dev_silver); > + if (IS_ERR_OR_NULL(np)) > + return PTR_ERR(np); This function (qcom_cpufreq_kryo_driver_init) returns zero on success. You are checking "np" here for being an error pointer, or NULL. What value do you think PTR_ERR() returns in the case of PTR_ERR(NULL)? IS_ERR_OR_NULL() is considered by some (me included) as being _very_ harmful because programmers generally fail to look at linux/err.h and consider what it means when used as above. -- RMK's Patch system: http://www.armlinux.org.uk/developer/patches/ FTTC broadband for 0.8mile line in suburbia: sync at 8.8Mbps down 630kbps up According to speedtest.net: 8.21Mbps down 510kbps up -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html