linux-kernel - [char-misc-next 7/9 RESEND] mei: support polling for event notification

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Date:	Sun, 26 Jul 2015 09:54:21 +0300
From:	Tomas Winkler <tomas.winkler@...el.com>
To:	Greg Kroah-Hartman <gregkh@...uxfoundation.org>
Cc:	arnd@...db.de, Alexander Usyskin <alexander.usyskin@...el.com>,
	linux-kernel@...r.kernel.org,
	Tomas Winkler <tomas.winkler@...el.com>
Subject: [char-misc-next 7/9 RESEND] mei: support polling for event notification

Polling on priority events is translated on waiting for event
notification. One need to enable notification prior for
calling select or poll system call otherwise process
will not wait.

Signed-off-by: Tomas Winkler <tomas.winkler@...el.com>
Signed-off-by: Alexander Usyskin <alexander.usyskin@...el.com>
---
 drivers/misc/mei/main.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/drivers/misc/mei/main.c b/drivers/misc/mei/main.c
index ffa70035af29..17b356f26686 100644
--- a/drivers/misc/mei/main.c
+++ b/drivers/misc/mei/main.c
@@ -608,6 +608,7 @@ static unsigned int mei_poll(struct file *file, poll_table *wait)
 	struct mei_cl *cl = file->private_data;
 	struct mei_device *dev;
 	unsigned int mask = 0;
+	bool notify_en;
 
 	if (WARN_ON(!cl || !cl->dev))
 		return POLLERR;
@@ -616,6 +617,7 @@ static unsigned int mei_poll(struct file *file, poll_table *wait)
 
 	mutex_lock(&dev->device_lock);
 
+	notify_en = cl->notify_en && (req_events & POLLPRI);
 
 	if (dev->dev_state != MEI_DEV_ENABLED ||
 	    !mei_cl_is_connected(cl)) {
@@ -628,6 +630,12 @@ static unsigned int mei_poll(struct file *file, poll_table *wait)
 		goto out;
 	}
 
+	if (notify_en) {
+		poll_wait(file, &cl->ev_wait, wait);
+		if (cl->notify_ev)
+			mask |= POLLPRI;
+	}
+
 	if (req_events & (POLLIN | POLLRDNORM)) {
 		poll_wait(file, &cl->rx_wait, wait);
 
-- 
2.4.3

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