Messages in this thread Patch in this message | | | From | Amit Kucheria <> | Date | Wed, 16 Oct 2019 22:20:48 +0530 | Subject | Re: [PATCH] thermal: create softlink by name for thermal_zone and cooling_device |
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On Tue, Oct 15, 2019 at 11:43 AM Wei Wang <wvw@google.com> wrote: > > The paths thermal_zone%d and cooling_device%d are not intuitive and the > numbers are subject to change due to device tree change. This usually > leads to tree traversal in userspace code. > The patch creates `tz-by-name' and `cdev-by-name' for thermal zone and > cooling_device respectively.
I like this.
> Signed-off-by: Wei Wang <wvw@google.com> > --- > drivers/thermal/thermal_core.c | 23 +++++++++++++++++++++-- > 1 file changed, 21 insertions(+), 2 deletions(-) > > diff --git a/drivers/thermal/thermal_core.c b/drivers/thermal/thermal_core.c > index d4481cc8958f..0ff8fb1d7b0a 100644 > --- a/drivers/thermal/thermal_core.c > +++ b/drivers/thermal/thermal_core.c > @@ -22,6 +22,7 @@ > #include <net/netlink.h> > #include <net/genetlink.h> > #include <linux/suspend.h> > +#include <linux/kobject.h> > > #define CREATE_TRACE_POINTS > #include <trace/events/thermal.h> > @@ -46,6 +47,8 @@ static DEFINE_MUTEX(poweroff_lock); > > static atomic_t in_suspend; > static bool power_off_triggered; > +static struct kobject *cdev_link_kobj; > +static struct kobject *tz_link_kobj; > > static struct thermal_governor *def_governor; > > @@ -954,7 +957,7 @@ __thermal_cooling_device_register(struct device_node *np, > struct thermal_zone_device *pos = NULL; > int result; > > - if (type && strlen(type) >= THERMAL_NAME_LENGTH) > + if (!type || !type[0] || strlen(type) >= THERMAL_NAME_LENGTH) > return ERR_PTR(-EINVAL);
This should be a separate fix, if needed.
> if (!ops || !ops->get_max_state || !ops->get_cur_state || > @@ -989,9 +992,15 @@ __thermal_cooling_device_register(struct device_node *np, > return ERR_PTR(result); > } > > - /* Add 'this' new cdev to the global cdev list */ > + /* Add 'this' new cdev to the global cdev list and create link*/ > mutex_lock(&thermal_list_lock); > list_add(&cdev->node, &thermal_cdev_list); > + if (!cdev_link_kobj) > + cdev_link_kobj = kobject_create_and_add("cdev-by-name", > + cdev->device.kobj.parent); > + if (!cdev_link_kobj || sysfs_create_link(cdev_link_kobj, > + &cdev->device.kobj, cdev->type)) > + dev_err(&cdev->device, "Failed to create cdev-by-name link\n");
Any reason not to use the following form instead? It seems easier to read.
if (!cdev_link_kobj) { cdev_link_kobj = kobject_create_and_add("cdev-by-name", cdev->device.kobj.parent); ret = sysfs_create_link(cdev_link_kobj, &cdev->device.kobj, cdev->type)) if (ret) dev_err(&cdev->device, "Failed to create cdev-by-name link\n"); }
> mutex_unlock(&thermal_list_lock); > > /* Update binding information for 'this' new cdev */ > @@ -1157,6 +1166,8 @@ void thermal_cooling_device_unregister(struct thermal_cooling_device *cdev) > } > } > } > + if (cdev_link_kobj) > + sysfs_remove_link(cdev_link_kobj, cdev->type); > > mutex_unlock(&thermal_list_lock); > > @@ -1340,6 +1351,12 @@ thermal_zone_device_register(const char *type, int trips, int mask, > > mutex_lock(&thermal_list_lock); > list_add_tail(&tz->node, &thermal_tz_list); > + if (!tz_link_kobj) > + tz_link_kobj = kobject_create_and_add("tz-by-name", > + tz->device.kobj.parent); > + if (!tz_link_kobj || sysfs_create_link(tz_link_kobj, > + &tz->device.kobj, tz->type)) > + dev_err(&tz->device, "Failed to create tz-by-name link\n");
Same as above.
> mutex_unlock(&thermal_list_lock); > > /* Bind cooling devices for this zone */ > @@ -1411,6 +1428,8 @@ void thermal_zone_device_unregister(struct thermal_zone_device *tz) > } > } > } > + if (tz_link_kobj) > + sysfs_remove_link(tz_link_kobj, tz->type); > > mutex_unlock(&thermal_list_lock); > > -- > 2.23.0.700.g56cf767bdb-goog >
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