[PATCH 4.9 09/31] HID: uhid: Fix returning EPOLLOUT from uhid_char_poll

[Greg Kroah-Hartman]

From: Marcel Holtmann <marcel@xxxxxxxxxxxx>

commit be54e7461ffdc5809b67d2aeefc1ddc9a91470c7 upstream.

Always return EPOLLOUT from uhid_char_poll to allow polling /dev/uhid
for writable state.

Fixes: 1f9dec1e0164 ("HID: uhid: allow poll()'ing on uhid devices")
Signed-off-by: Marcel Holtmann <marcel@xxxxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Jiri Kosina <jkosina@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 drivers/hid/uhid.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

--- a/drivers/hid/uhid.c
+++ b/drivers/hid/uhid.c
@@ -26,6 +26,7 @@
 #include <linux/uhid.h>
 #include <linux/wait.h>
 #include <linux/uaccess.h>
+#include <linux/eventpoll.h>
 
 #define UHID_NAME	"uhid"
 #define UHID_BUFSIZE	32
@@ -774,7 +775,7 @@ static unsigned int uhid_char_poll(struc
 	if (uhid->head != uhid->tail)
 		return POLLIN | POLLRDNORM;
 
-	return 0;
+	return EPOLLOUT | EPOLLWRNORM;
 }
 
 static const struct file_operations uhid_fops = {