Commit d2178fc8 authored Jul 09, 2019 by Fabian Henneke Committed by Greg Kroah-Hartman Jan 17, 2020

hidraw: Return EPOLLOUT from hidraw_poll



[ Upstream commit 378b80370aa1fe50f9c48a3ac8af3e416e73b89f ]

Always return EPOLLOUT from hidraw_poll when a device is connected.
This is safe since writes are always possible (but will always block).

hidraw does not support non-blocking writes and instead always calls
blocking backend functions on write requests. Hence, so far, a call to
poll never returned EPOLLOUT, which confuses tools like socat.

Signed-off-by: Fabian Henneke <fabian.henneke@gmail.com>
In-reply-to: <CA+hv5qkyis03CgYTWeWX9cr0my-d2Oe+aZo+mjmWRXgjrGqyrw@mail.gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Sasha Levin <sashal@kernel.org>

parent db5b9190

drivers/hid/hidraw.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -260,7 +260,7 @@ 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;
		return EPOLLIN \| EPOLLRDNORM \| EPOLLOUT;
		if (!list->hidraw->exist)
		return EPOLLERR \| EPOLLHUP;
		return 0;