From 9f3b61dc1dd7b81e99e7ed23776bb64a35f39e1a Mon Sep 17 00:00:00 2001
From: Marcel Holtmann <marcel@holtmann.org>
Date: Wed, 4 Dec 2019 03:37:13 +0100
Subject: [PATCH] HID: hidraw: Fix returning EPOLLOUT from hidraw_poll
Git-commit: 9f3b61dc1dd7b81e99e7ed23776bb64a35f39e1a
Patch-mainline: v5.5-rc6
References: bsc#1051510

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>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/hid/hidraw.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/drivers/hid/hidraw.c
+++ b/drivers/hid/hidraw.c
@@ -260,10 +260,10 @@ static unsigned int hidraw_poll(struct f
 
 	poll_wait(file, &list->hidraw->wait, wait);
 	if (list->head != list->tail)
-		return POLLIN | POLLRDNORM | POLLOUT;
+		return POLLIN | POLLRDNORM;
 	if (!list->hidraw->exist)
 		return POLLERR | POLLHUP;
-	return 0;
+	return POLLOUT | POLLWRNORM;
 }
 
 static int hidraw_open(struct inode *inode, struct file *file)