Commit 9f3b61dc authored Dec 04, 2019 by Marcel Holtmann Committed by Jiri Kosina Dec 09, 2019

HID: hidraw: Fix returning EPOLLOUT from hidraw_poll



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: 378b8037 ("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>

parent d004701d

drivers/hid/hidraw.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -252,10 +252,10 @@ static __poll_t hidraw_poll(struct file file, poll_table wait)

		poll_wait(file, &list->hidraw->wait, wait);
		if (list->head != list->tail)
		return EPOLLIN \| EPOLLRDNORM \| EPOLLOUT;
		return EPOLLIN \| EPOLLRDNORM;
		if (!list->hidraw->exist)
		return EPOLLERR \| EPOLLHUP;
		return 0;
		return EPOLLOUT \| EPOLLWRNORM;
		}

		static int hidraw_open(struct inode inode, struct file file)

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