From 1eb5bd4d83f566e5ea8521b6020d0cfcb8f1c3ef Mon Sep 17 00:00:00 2001 From: Alexander Usyskin Date: Thu, 16 Jun 2016 17:58:54 +0300 Subject: [PATCH] mei: drop read complete queue emptiness check In the course of the read flow we want to wait for read completion only if the read queue is empty. However the calling list_empty(&cl->rd_completed) is a duplication as the same check was performed by mei_cl_read_cb() and the waiting is skipped if it returns not NULL. Signed-off-by: Alexander Usyskin Signed-off-by: Tomas Winkler Signed-off-by: Greg Kroah-Hartman --- drivers/misc/mei/bus.c | 3 ++- drivers/misc/mei/main.c | 3 ++- 2 files changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/misc/mei/bus.c b/drivers/misc/mei/bus.c index 1f33fea9299f..63411ddfb83d 100644 --- a/drivers/misc/mei/bus.c +++ b/drivers/misc/mei/bus.c @@ -126,7 +126,8 @@ ssize_t __mei_cl_recv(struct mei_cl *cl, u8 *buf, size_t length) goto out; /* wait on event only if there is no other waiter */ - if (list_empty(&cl->rd_completed) && !waitqueue_active(&cl->rx_wait)) { + /* synchronized under device mutex */ + if (!waitqueue_active(&cl->rx_wait)) { mutex_unlock(&bus->device_lock); diff --git a/drivers/misc/mei/main.c b/drivers/misc/mei/main.c index a8d0471f817f..3326bde7fba1 100644 --- a/drivers/misc/mei/main.c +++ b/drivers/misc/mei/main.c @@ -183,7 +183,8 @@ static ssize_t mei_read(struct file *file, char __user *ubuf, goto out; } - if (list_empty(&cl->rd_completed) && !waitqueue_active(&cl->rx_wait)) { + /* synchronized under device mutex */ + if (!waitqueue_active(&cl->rx_wait)) { if (file->f_flags & O_NONBLOCK) { rets = -EAGAIN; goto out; -- 2.20.1