hidraw: Return EPOLLOUT from hidraw_poll
authorFabian Henneke <fabian.henneke@gmail.com>
Tue, 9 Jul 2019 11:03:37 +0000 (13:03 +0200)
committerJiri Kosina <jkosina@suse.cz>
Mon, 5 Aug 2019 12:07:13 +0000 (14:07 +0200)
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>
drivers/hid/hidraw.c

index 006bd6f..24f40a3 100644 (file)
@@ -252,7 +252,7 @@ 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;