mei: don't get stuck in select during reset

Clear pending connection after hw reset but before hw start
and wake up the waiting task in poll. Signal POLLERR in select
when device went through reset.

Add wrapper mei_cl_is_connected for checking if
the device and client are connected.

Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 15 insertions, 7 deletions

diff --git a/drivers/misc/mei/main.c b/drivers/misc/mei/main.c
index 5e11b5b9b65d..173ff095be0d 100644
--- a/drivers/misc/mei/main.c
+++ b/drivers/misc/mei/main.c
@@ -625,24 +625,32 @@ static unsigned int mei_poll(struct file *file, poll_table *wait)
         unsigned int mask = 0;
 
         if (WARN_ON(!cl || !cl->dev))
-                return mask;
+                return POLLERR;
 
         dev = cl->dev;
 
         mutex_lock(&dev->device_lock);
 
-        if (dev->dev_state != MEI_DEV_ENABLED)
-                goto out;
-
-
-        if (cl == &dev->iamthif_cl) {
-                mask = mei_amthif_poll(dev, file, wait);
+        if (!mei_cl_is_connected(cl)) {
+                mask = POLLERR;
                 goto out;
         }
 
         mutex_unlock(&dev->device_lock);
+
+
+        if (cl == &dev->iamthif_cl)
+                return mei_amthif_poll(dev, file, wait);
+
         poll_wait(file, &cl->tx_wait, wait);
+
         mutex_lock(&dev->device_lock);
+
+        if (!mei_cl_is_connected(cl)) {
+                mask = POLLERR;
+                goto out;
+        }
+
         if (MEI_WRITE_COMPLETE == cl->writing_state)
                 mask |= (POLLIN | POLLRDNORM);