pwm: Set class for exported channels in sysfs

Message ID
State Deferred
Headers show

Commit Message

Gottfried Haider May 1, 2017, 6:59 a.m.
Notifications for devices without bus or class set get dropped by
dev_uevent_filter. Adding the class to the exported child matches
what the gpio subsystem is doing.

With this change exporting a channel triggers a udev event, which
gives userspace a chance to fixup permissions and makes it possible
for non-root users to make use of the pwm subsystem.

Signed-off-by: Gottfried Haider <>
 drivers/pwm/sysfs.c | 1 +
 1 file changed, 1 insertion(+)


Gottfried Haider May 15, 2017, 11:07 a.m. | #1
Does anyone have time to review this patch?

I wrote this with the Raspberry Pi in mind, but they want to see this
at least acknowledged by upstream before carrying in their downstream
tree (which seems quite sensible to me).

Thanks in advance,
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diff --git a/drivers/pwm/sysfs.c b/drivers/pwm/sysfs.c
index a813239..83f2b0b 100644
--- a/drivers/pwm/sysfs.c
+++ b/drivers/pwm/sysfs.c
@@ -263,6 +263,7 @@  static int pwm_export_child(struct device *parent, struct pwm_device *pwm)
 	export->pwm = pwm;
+	export->child.class = parent->class;
 	export->child.release = pwm_export_release;
 	export->child.parent = parent;
 	export->child.devt = MKDEV(0, 0);