Question about dev_uevent_filter

From: Lan Tianyu
Date: Tue Sep 25 2012 - 11:13:39 EST



hi Greg:
I find only devices which has bus_type or class can add uevent callback
and output the uevent information. This is because the dev_uevent_filter just return
true for these devices. But some device may not have class and bus_type.
e.g usb endpoint, if we assigned them to usb_bus_type, device core will
try to create sysfs directory link under /sys/bus/usb. But endpoint sysfs
directory's name are same for each usb devices.e.g ep_00, every usb device will
create the endpoint. So in this situation, we can't assign usb endpoint to
usb_bus_type. So even if uevent callback was added and with some information,
it still couldn't output anything. Can we add dev->type check in the
dev_uevent_filter() and return 1 if type exits?

/drivers/base/core.c
static int dev_uevent_filter(struct kset *kset, struct kobject *kobj)
{
struct kobj_type *ktype = get_ktype(kobj);

if (ktype == &device_ktype) {
struct device *dev = kobj_to_dev(kobj);
if (dev->bus)
return 1;
if (dev->class)
return 1;
}
return 0;
}

Thanks
--
Best regards
Tianyu Lan
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