[3.8.y.z extended stable] Patch "mei: ignore client writing state during cb completion" has been added to staging queue

[Kamal Mostafa]

This is a note to let you know that I have just added a patch titled

    mei: ignore client writing state during cb completion

to the linux-3.8.y-queue branch of the 3.8.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.8.y-queue

This patch is scheduled to be released in version 3.8.13.24.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.8.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

------

>From 014fa8819116ed6dd9202bb2a4b42f1fed5e7f44 Mon Sep 17 00:00:00 2001
From: Alexander Usyskin <alexander.usyskin at intel.com>
Date: Tue, 1 Apr 2014 23:50:41 +0300
Subject: mei: ignore client writing state during cb completion

commit 34ec43661fe8f1977dd0f05353302ae2ed10aabb upstream.

Ignore client writing state during cb completion to fix a memory
leak.

When moving cbs to the completion list we should not look at
writing_state as this state can be already overwritten by next
write, the fact that a cb is on the write waiting list means
that it was already written to the HW and we can safely complete it.

Same pays for wait in poll handler, we do not have to check the state
wake is done after completion list processing.

Signed-off-by: Alexander Usyskin <alexander.usyskin at intel.com>
Signed-off-by: Tomas Winkler <tomas.winkler at intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh at linuxfoundation.org>
[ kamal: backport to 3.8: context ]
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 drivers/misc/mei/interrupt.c | 3 +--
 drivers/misc/mei/main.c      | 3 +--
 2 files changed, 2 insertions(+), 4 deletions(-)

diff --git a/drivers/misc/mei/interrupt.c b/drivers/misc/mei/interrupt.c
index 04fa213..b7fed05 100644
--- a/drivers/misc/mei/interrupt.c
+++ b/drivers/misc/mei/interrupt.c
@@ -906,8 +906,7 @@ static int mei_irq_thread_write_handler(struct mei_device *dev,

 		cl->status = 0;
 		list_del(&pos->list);
-		if (MEI_WRITING == cl->writing_state &&
-		    pos->fop_type == MEI_FOP_WRITE &&
+		if (pos->fop_type == MEI_FOP_WRITE &&
 		    cl != &dev->iamthif_cl) {
 			dev_dbg(&dev->pdev->dev, "MEI WRITE COMPLETE\n");
 			cl->writing_state = MEI_WRITE_COMPLETE;
diff --git a/drivers/misc/mei/main.c b/drivers/misc/mei/main.c
index 43fb52f..9ad4ae0 100644
--- a/drivers/misc/mei/main.c
+++ b/drivers/misc/mei/main.c
@@ -701,8 +701,7 @@ static unsigned int mei_poll(struct file *file, poll_table *wait)
 	mutex_unlock(&dev->device_lock);
 	poll_wait(file, &cl->tx_wait, wait);
 	mutex_lock(&dev->device_lock);
-	if (MEI_WRITE_COMPLETE == cl->writing_state)
-		mask |= (POLLIN | POLLRDNORM);
+	mask |= (POLLIN | POLLRDNORM);

 out:
 	mutex_unlock(&dev->device_lock);
--
1.9.1