HID: hidraw: Fix returning EPOLLOUT from hidraw_poll
authorMarcel Holtmann <marcel@holtmann.org>
Wed, 4 Dec 2019 02:37:13 +0000 (03:37 +0100)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Tue, 14 Jan 2020 19:08:23 +0000 (20:08 +0100)
commite38d7bb30cbe8f9070607a424bb25f27c3cf3d35
tree3aee9b4603ab3bd8df2147825c295efd84970e1f
parent566dbc0db3fc58335df35336083feb44649051a3
HID: hidraw: Fix returning EPOLLOUT from hidraw_poll

commit 9f3b61dc1dd7b81e99e7ed23776bb64a35f39e1a upstream.

When polling a connected /dev/hidrawX device, it is useful to get the
EPOLLOUT when writing is possible. Since writing is possible as soon as
the device is connected, always return it.

Right now EPOLLOUT is only returned when there are also input reports
are available. This works if devices start sending reports when
connected, but some HID devices might need an output report first before
sending any input reports. This change will allow using EPOLLOUT here as
well.

Fixes: 378b80370aa1 ("hidraw: Return EPOLLOUT from hidraw_poll")
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Cc: stable@vger.kernel.org
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/hid/hidraw.c