On Monday 15 February 2016 21:56:42 Viresh Kumar wrote: > We are currently required to do two checks for regulator pointer: > IS_ERR() and IS_NULL(). > > And multiple instances are reported, about both of these not being used > consistently and so resulting in crashes. > > Fix that by initializing regulator pointer with an error value and > checking it only against an error. > > This makes code consistent and efficient.
There is usually something else wrong if you have to check for both. Why exactly do you need to check for both IS_ERR and NULL? > diff --git a/drivers/base/power/opp/core.c b/drivers/base/power/opp/core.c > index d7cd4e265766..146b6197d598 100644 > --- a/drivers/base/power/opp/core.c > +++ b/drivers/base/power/opp/core.c > @@ -257,7 +257,7 @@ unsigned long dev_pm_opp_get_max_volt_latency(struct > device *dev) > } > > reg = dev_opp->regulator; > - if (IS_ERR_OR_NULL(reg)) { > + if (IS_ERR(reg)) { > /* Regulator may not be required for device */ > if (reg) > dev_err(dev, "%s: Invalid regulator (%ld)\n", __func__, > @@ -798,6 +798,9 @@ static struct device_opp *_add_device_opp(struct device > *dev) > of_node_put(np); > } > > + /* Set regulator to a non-NULL error value */ > + dev_opp->regulator = ERR_PTR(-EFAULT); > + > /* Find clk for the device */ > dev_opp->clk = clk_get(dev, NULL); > if (IS_ERR(dev_opp->clk)) { -EFAULT has a very specific meaning (accessing an invalid pointer from user space), I don't think you want that one. Arnd