From 9f3b61dc1dd7b81e99e7ed23776bb64a35f39e1a Mon Sep 17 00:00:00 2001 From: Marcel Holtmann Date: Wed, 4 Dec 2019 03:37:13 +0100 Subject: 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: 378b80370aa1 ("hidraw: Return EPOLLOUT from hidraw_poll") Signed-off-by: Marcel Holtmann Cc: stable@vger.kernel.org Signed-off-by: Jiri Kosina --- drivers/hid/hidraw.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'drivers/hid/hidraw.c') diff --git a/drivers/hid/hidraw.c b/drivers/hid/hidraw.c index c3fc0ceb8096..f61f2123a755 100644 --- 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) -- cgit From 9e635c2851df6caee651e589fbf937b637973c91 Mon Sep 17 00:00:00 2001 From: Jiri Kosina Date: Fri, 10 Jan 2020 15:32:51 +0100 Subject: HID: hidraw, uhid: Always report EPOLLOUT 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 --- drivers/hid/hidraw.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) (limited to 'drivers/hid/hidraw.c') diff --git a/drivers/hid/hidraw.c b/drivers/hid/hidraw.c index f61f2123a755..7a75aff78388 100644 --- a/drivers/hid/hidraw.c +++ b/drivers/hid/hidraw.c @@ -249,13 +249,14 @@ out: static __poll_t hidraw_poll(struct file *file, poll_table *wait) { struct hidraw_list *list = file->private_data; + __poll_t mask = EPOLLOUT | EPOLLWRNORM; /* hidraw is always writable */ poll_wait(file, &list->hidraw->wait, wait); if (list->head != list->tail) - return EPOLLIN | EPOLLRDNORM; + mask |= EPOLLIN | EPOLLRDNORM; if (!list->hidraw->exist) - return EPOLLERR | EPOLLHUP; - return EPOLLOUT | EPOLLWRNORM; + mask |= EPOLLERR | EPOLLHUP; + return mask; } static int hidraw_open(struct inode *inode, struct file *file) -- cgit