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: c33b602bb2eb ("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>

diff --git a/drivers/hid/hidraw.c b/drivers/hid/hidraw.c
index c3fc0ceb80963c331f1515bacdfa51883708d1ae..f61f2123a7554d9e9bbcf6ffe42c9cebc70f2f95 100644 (file)
--- a/drivers/hid/hidraw.c
+++ b/drivers/hid/hidraw.c
@@ -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)