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

From: Tomas Winkler
Date: Wed Jun 24 2015 - 05:02:13 EST


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@xxxxxxxxx>
Signed-off-by: Alexander Usyskin <alexander.usyskin@xxxxxxxxx>
---
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 4a3f72986ecb..79892a480de5 100644
--- a/drivers/misc/mei/main.c
+++ b/drivers/misc/mei/main.c
@@ -607,6 +607,7 @@ 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;
@@ -615,6 +616,7 @@ 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)) {
@@ -627,6 +629,12 @@ 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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