From acebe8464be16133c656c5578e325ee69db12166 Mon Sep 17 00:00:00 2001 From: Jiri Kosina Date: Fri, 10 Jan 2020 15:32:51 +0100 Subject: [PATCH] HID: hidraw, uhid: Always report EPOLLOUT [ Upstream commit 9e635c2851df6caee651e589fbf937b637973c91 ] hidraw and uhid device nodes are always available for writing so we should always report EPOLLOUT and EPOLLWRNORM bits, not only in the cases when there is nothing to read. Reported-by: Linus Torvalds Fixes: be54e7461ffdc ("HID: uhid: Fix returning EPOLLOUT from uhid_char_poll") Fixes: 9f3b61dc1dd7b ("HID: hidraw: Fix returning EPOLLOUT from hidraw_poll") Signed-off-by: Jiri Kosina Signed-off-by: Sasha Levin --- drivers/hid/hidraw.c | 7 ++++--- drivers/hid/uhid.c | 5 +++-- 2 files changed, 7 insertions(+), 5 deletions(-) diff --git a/drivers/hid/hidraw.c b/drivers/hid/hidraw.c index e60d9c88bd35..ef9e196b54a5 100644 --- a/drivers/hid/hidraw.c +++ b/drivers/hid/hidraw.c @@ -262,13 +262,14 @@ out: static unsigned int hidraw_poll(struct file *file, poll_table *wait) { struct hidraw_list *list = file->private_data; + unsigned int mask = POLLOUT | POLLWRNORM; /* hidraw is always writable */ poll_wait(file, &list->hidraw->wait, wait); if (list->head != list->tail) - return POLLIN | POLLRDNORM; + mask |= POLLIN | POLLRDNORM; if (!list->hidraw->exist) - return POLLERR | POLLHUP; - return POLLOUT | POLLWRNORM; + mask |= POLLERR | POLLHUP; + return mask; } static int hidraw_open(struct inode *inode, struct file *file) diff --git a/drivers/hid/uhid.c b/drivers/hid/uhid.c index ea0c860ee842..a7ba4db8cff7 100644 --- a/drivers/hid/uhid.c +++ b/drivers/hid/uhid.c @@ -769,13 +769,14 @@ unlock: static unsigned int uhid_char_poll(struct file *file, poll_table *wait) { struct uhid_device *uhid = file->private_data; + unsigned int mask = POLLOUT | POLLWRNORM; /* uhid is always writable */ poll_wait(file, &uhid->waitq, wait); if (uhid->head != uhid->tail) - return POLLIN | POLLRDNORM; + mask |= POLLIN | POLLRDNORM; - return EPOLLOUT | EPOLLWRNORM; + return mask; } static const struct file_operations uhid_fops = {