From: Marcel Holtmann marcel@holtmann.org
[ Upstream commit 9f3b61dc1dd7b81e99e7ed23776bb64a35f39e1a ]
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 Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/hid/hidraw.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/hid/hidraw.c b/drivers/hid/hidraw.c index 1ac82e194818..1abf5008def0 100644 --- a/drivers/hid/hidraw.c +++ b/drivers/hid/hidraw.c @@ -260,10 +260,10 @@ static unsigned int hidraw_poll(struct file *file, poll_table *wait)
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)