[PATCH] drm/sysfs: fix hotplug regression since lifetime changes

[Dave Airlie]

On Thu, Nov 21, 2013 at 7:49 PM, David Herrmann <dh.herrmann at gmail.com> wrote:
> Hi
>
> On Thu, Nov 21, 2013 at 10:25 AM, Dave Airlie <airlied at gmail.com> wrote:
>> On Thu, Nov 21, 2013 at 7:22 PM, Daniel Vetter <daniel at ffwll.ch> wrote:
>>> On Thu, Nov 21, 2013 at 11:51:04AM +1000, Dave Airlie wrote:
>>>> 5bdebb183c9702a8c57a01dff09337be3de337a6 changed the lifetimes, but it
>>>> also meant we no longer set the device_type field properly, so the
>>>> hotplug events in userspace weren't fully formed enough for drivers to care.
>>>>
>>>> Reported-by: Jesse Barnes <jbarnes at virtuosugeek.org>
>>>> Signed-off-by: Dave Airlie <airlied at redhat.com>
>>>> ---
>>>>  drivers/gpu/drm/drm_sysfs.c | 1 +
>>>>  1 file changed, 1 insertion(+)
>>>>
>>>> diff --git a/drivers/gpu/drm/drm_sysfs.c b/drivers/gpu/drm/drm_sysfs.c
>>>> index 1a35ea5..c6a3902 100644
>>>> --- a/drivers/gpu/drm/drm_sysfs.c
>>>> +++ b/drivers/gpu/drm/drm_sysfs.c
>>>> @@ -516,6 +516,7 @@ int drm_sysfs_device_add(struct drm_minor *minor)
>>>>               DRM_ERROR("device create failed %ld\n", PTR_ERR(minor->kdev));
>>>>               return PTR_ERR(minor->kdev);
>>>>       }
>>>> +     minor->kdev->type = &drm_sysfs_device_minor;
>>>
>>> Isn't this one of the sysfs races Greg is fighting against? At least from
>>> a cursor read through the driver core it looks like we'd better set the
>>> dev->type before we set it up with device_create().
>>
>> Possibly but how can we do that? since minor->kdev is something we
>> just created 2 lines earlier
>> unless there is another create function I should be calling, I don't
>> see a device_create_with_type.
>
> See device_create_groups_vargs() in drivers/base/core.c. Just copy the
> code from it and do device initialization yourself. device_create() is
> only a wrapper around kzalloc()+device_register() anyway.
>

It does seem a bit like cut-n-paste magic to me to do that,

It does however seem to be the accepted norm.

Dave.