| Message ID | 20230313182918.1312597-6-gregkh@linuxfoundation.org (mailing list archive) |
|---|---|
| State | Changes Requested, archived |
| Headers | show |
| Series | None | expand |
On Mon, Mar 13, 2023 at 7:30 PM Greg Kroah-Hartman <gregkh@linuxfoundation.org> wrote: > > Direct access to the struct bus_type dev_root pointer is going away soon > so replace that with a call to bus_get_dev_root() instead, which is what > it is there for. > > This allows us to clean up the cpuidle_add_interface() call a bit as it > was only called in one place, with the same argument so just put that > into the function itself. Note that cpuidle_remove_interface() should > also probably be removed in the future as there are no callers of it for > some reason. > > Cc: "Rafael J. Wysocki" <rafael@kernel.org> > Cc: Daniel Lezcano <daniel.lezcano@linaro.org> > Cc: linux-pm@vger.kernel.org > Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> > --- > Note, this is a patch that is a prepatory cleanup as part of a larger > series of patches that is working on resolving some old driver core > design mistakes. It will build and apply cleanly on top of 6.3-rc2 on > its own, but I'd prefer if I could take it through my driver-core tree > so that the driver core changes can be taken through there for 6.4-rc1. > > drivers/cpuidle/cpuidle.c | 2 +- > drivers/cpuidle/cpuidle.h | 2 +- > drivers/cpuidle/sysfs.c | 12 +++++++++--- > 3 files changed, 11 insertions(+), 5 deletions(-) > > diff --git a/drivers/cpuidle/cpuidle.c b/drivers/cpuidle/cpuidle.c > index 0b00f21cefe3..8e929f6602ce 100644 > --- a/drivers/cpuidle/cpuidle.c > +++ b/drivers/cpuidle/cpuidle.c > @@ -808,7 +808,7 @@ static int __init cpuidle_init(void) > if (cpuidle_disabled()) > return -ENODEV; > > - return cpuidle_add_interface(cpu_subsys.dev_root); > + return cpuidle_add_interface(); > } > > module_param(off, int, 0444); > diff --git a/drivers/cpuidle/cpuidle.h b/drivers/cpuidle/cpuidle.h > index 9f336af17fa6..52701d9588f1 100644 > --- a/drivers/cpuidle/cpuidle.h > +++ b/drivers/cpuidle/cpuidle.h > @@ -30,7 +30,7 @@ extern int cpuidle_switch_governor(struct cpuidle_governor *gov); > > struct device; > > -extern int cpuidle_add_interface(struct device *dev); > +extern int cpuidle_add_interface(void); > extern void cpuidle_remove_interface(struct device *dev); > extern int cpuidle_add_device_sysfs(struct cpuidle_device *device); > extern void cpuidle_remove_device_sysfs(struct cpuidle_device *device); > diff --git a/drivers/cpuidle/sysfs.c b/drivers/cpuidle/sysfs.c > index 48948b171749..84e4946f1072 100644 > --- a/drivers/cpuidle/sysfs.c > +++ b/drivers/cpuidle/sysfs.c > @@ -119,11 +119,17 @@ static struct attribute_group cpuidle_attr_group = { > > /** > * cpuidle_add_interface - add CPU global sysfs attributes > - * @dev: the target device > */ > -int cpuidle_add_interface(struct device *dev) > +int cpuidle_add_interface(void) > { > - return sysfs_create_group(&dev->kobj, &cpuidle_attr_group); > + struct device *dev_root = bus_get_dev_root(&cpu_subsys); > + int retval = -EINVAL; > + > + if (dev_root) { > + retval = sysfs_create_group(&dev_root->kobj, &cpuidle_attr_group); > + put_device(dev_root); > + } > + return retval; I would prefer if (!dev_root) return -EINVAL; retval = sysfs_create_group(&dev_root->kobj, &cpuidle_attr_group); put_device(dev_root); return retval; assuming that successful group creation will bump up the reference counter of dev_root.
On Mon, Mar 13, 2023 at 07:58:02PM +0100, Rafael J. Wysocki wrote: > On Mon, Mar 13, 2023 at 7:30 PM Greg Kroah-Hartman > <gregkh@linuxfoundation.org> wrote: > > > > Direct access to the struct bus_type dev_root pointer is going away soon > > so replace that with a call to bus_get_dev_root() instead, which is what > > it is there for. > > > > This allows us to clean up the cpuidle_add_interface() call a bit as it > > was only called in one place, with the same argument so just put that > > into the function itself. Note that cpuidle_remove_interface() should > > also probably be removed in the future as there are no callers of it for > > some reason. > > > > Cc: "Rafael J. Wysocki" <rafael@kernel.org> > > Cc: Daniel Lezcano <daniel.lezcano@linaro.org> > > Cc: linux-pm@vger.kernel.org > > Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> > > --- > > Note, this is a patch that is a prepatory cleanup as part of a larger > > series of patches that is working on resolving some old driver core > > design mistakes. It will build and apply cleanly on top of 6.3-rc2 on > > its own, but I'd prefer if I could take it through my driver-core tree > > so that the driver core changes can be taken through there for 6.4-rc1. > > > > drivers/cpuidle/cpuidle.c | 2 +- > > drivers/cpuidle/cpuidle.h | 2 +- > > drivers/cpuidle/sysfs.c | 12 +++++++++--- > > 3 files changed, 11 insertions(+), 5 deletions(-) > > > > diff --git a/drivers/cpuidle/cpuidle.c b/drivers/cpuidle/cpuidle.c > > index 0b00f21cefe3..8e929f6602ce 100644 > > --- a/drivers/cpuidle/cpuidle.c > > +++ b/drivers/cpuidle/cpuidle.c > > @@ -808,7 +808,7 @@ static int __init cpuidle_init(void) > > if (cpuidle_disabled()) > > return -ENODEV; > > > > - return cpuidle_add_interface(cpu_subsys.dev_root); > > + return cpuidle_add_interface(); > > } > > > > module_param(off, int, 0444); > > diff --git a/drivers/cpuidle/cpuidle.h b/drivers/cpuidle/cpuidle.h > > index 9f336af17fa6..52701d9588f1 100644 > > --- a/drivers/cpuidle/cpuidle.h > > +++ b/drivers/cpuidle/cpuidle.h > > @@ -30,7 +30,7 @@ extern int cpuidle_switch_governor(struct cpuidle_governor *gov); > > > > struct device; > > > > -extern int cpuidle_add_interface(struct device *dev); > > +extern int cpuidle_add_interface(void); > > extern void cpuidle_remove_interface(struct device *dev); > > extern int cpuidle_add_device_sysfs(struct cpuidle_device *device); > > extern void cpuidle_remove_device_sysfs(struct cpuidle_device *device); > > diff --git a/drivers/cpuidle/sysfs.c b/drivers/cpuidle/sysfs.c > > index 48948b171749..84e4946f1072 100644 > > --- a/drivers/cpuidle/sysfs.c > > +++ b/drivers/cpuidle/sysfs.c > > @@ -119,11 +119,17 @@ static struct attribute_group cpuidle_attr_group = { > > > > /** > > * cpuidle_add_interface - add CPU global sysfs attributes > > - * @dev: the target device > > */ > > -int cpuidle_add_interface(struct device *dev) > > +int cpuidle_add_interface(void) > > { > > - return sysfs_create_group(&dev->kobj, &cpuidle_attr_group); > > + struct device *dev_root = bus_get_dev_root(&cpu_subsys); > > + int retval = -EINVAL; > > + > > + if (dev_root) { > > + retval = sysfs_create_group(&dev_root->kobj, &cpuidle_attr_group); > > + put_device(dev_root); > > + } > > + return retval; > > I would prefer > > if (!dev_root) > return -EINVAL; > > retval = sysfs_create_group(&dev_root->kobj, &cpuidle_attr_group); > put_device(dev_root); > return retval; > > assuming that successful group creation will bump up the reference > counter of dev_root. That is correct. I'll respin this with this change in it now, thanks for the review! greg k-h
diff --git a/drivers/cpuidle/cpuidle.c b/drivers/cpuidle/cpuidle.c index 0b00f21cefe3..8e929f6602ce 100644 --- a/drivers/cpuidle/cpuidle.c +++ b/drivers/cpuidle/cpuidle.c @@ -808,7 +808,7 @@ static int __init cpuidle_init(void) if (cpuidle_disabled()) return -ENODEV; - return cpuidle_add_interface(cpu_subsys.dev_root); + return cpuidle_add_interface(); } module_param(off, int, 0444); diff --git a/drivers/cpuidle/cpuidle.h b/drivers/cpuidle/cpuidle.h index 9f336af17fa6..52701d9588f1 100644 --- a/drivers/cpuidle/cpuidle.h +++ b/drivers/cpuidle/cpuidle.h @@ -30,7 +30,7 @@ extern int cpuidle_switch_governor(struct cpuidle_governor *gov); struct device; -extern int cpuidle_add_interface(struct device *dev); +extern int cpuidle_add_interface(void); extern void cpuidle_remove_interface(struct device *dev); extern int cpuidle_add_device_sysfs(struct cpuidle_device *device); extern void cpuidle_remove_device_sysfs(struct cpuidle_device *device); diff --git a/drivers/cpuidle/sysfs.c b/drivers/cpuidle/sysfs.c index 48948b171749..84e4946f1072 100644 --- a/drivers/cpuidle/sysfs.c +++ b/drivers/cpuidle/sysfs.c @@ -119,11 +119,17 @@ static struct attribute_group cpuidle_attr_group = { /** * cpuidle_add_interface - add CPU global sysfs attributes - * @dev: the target device */ -int cpuidle_add_interface(struct device *dev) +int cpuidle_add_interface(void) { - return sysfs_create_group(&dev->kobj, &cpuidle_attr_group); + struct device *dev_root = bus_get_dev_root(&cpu_subsys); + int retval = -EINVAL; + + if (dev_root) { + retval = sysfs_create_group(&dev_root->kobj, &cpuidle_attr_group); + put_device(dev_root); + } + return retval; } /**
Direct access to the struct bus_type dev_root pointer is going away soon so replace that with a call to bus_get_dev_root() instead, which is what it is there for. This allows us to clean up the cpuidle_add_interface() call a bit as it was only called in one place, with the same argument so just put that into the function itself. Note that cpuidle_remove_interface() should also probably be removed in the future as there are no callers of it for some reason. Cc: "Rafael J. Wysocki" <rafael@kernel.org> Cc: Daniel Lezcano <daniel.lezcano@linaro.org> Cc: linux-pm@vger.kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> --- Note, this is a patch that is a prepatory cleanup as part of a larger series of patches that is working on resolving some old driver core design mistakes. It will build and apply cleanly on top of 6.3-rc2 on its own, but I'd prefer if I could take it through my driver-core tree so that the driver core changes can be taken through there for 6.4-rc1. drivers/cpuidle/cpuidle.c | 2 +- drivers/cpuidle/cpuidle.h | 2 +- drivers/cpuidle/sysfs.c | 12 +++++++++--- 3 files changed, 11 insertions(+), 5 deletions(-)