patch "mei: txe: reduce suspend/resume time" added to char-misc-next

patch "mei: txe: reduce suspend/resume time" added to char-misc-next

[gregkh]

This is a note to let you know that I've just added the patch titled

    mei: txe: reduce suspend/resume time

to my char-misc git tree which can be found at
    git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc.git
in the char-misc-next branch.

The patch will show up in the next release of the linux-next tree
(usually sometime within the next 24 hours during the week.)

The patch will also be merged in the next major kernel release
during the merge window.

If you have any questions about this process, please let me know.


>From fe292283c23329218e384bffc6cb4bfa3fd92277 Mon Sep 17 00:00:00 2001
From: Tomas Winkler <tomas.winkler@intel.com>
Date: Tue, 14 Apr 2015 10:27:26 +0300
Subject: mei: txe: reduce suspend/resume time

HW has to be in known state before the initialisation
sequence is started. The polling step for settling aliveness
was set to 200ms while in practise this can be done in up to 30msecs.

Cc: <stable@vger.kernel.org> #3.18+
Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Barak Yoresh <barak.yoresh@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/misc/mei/hw-txe.c | 20 ++++++++++----------
 1 file changed, 10 insertions(+), 10 deletions(-)

diff --git a/drivers/misc/mei/hw-txe.c b/drivers/misc/mei/hw-txe.c
index 7abafe7d120d..1cd223c96864 100644
--- a/drivers/misc/mei/hw-txe.c
+++ b/drivers/misc/mei/hw-txe.c
@@ -16,6 +16,7 @@
 
 #include <linux/pci.h>
 #include <linux/jiffies.h>
+#include <linux/ktime.h>
 #include <linux/delay.h>
 #include <linux/kthread.h>
 #include <linux/irqreturn.h>
@@ -218,26 +219,25 @@ static u32 mei_txe_aliveness_get(struct mei_device *dev)
  *
  * Polls for HICR_HOST_ALIVENESS_RESP.ALIVENESS_RESP to be set
  *
- * Return: > 0 if the expected value was received, -ETIME otherwise
+ * Return: 0 if the expected value was received, -ETIME otherwise
  */
 static int mei_txe_aliveness_poll(struct mei_device *dev, u32 expected)
 {
 	struct mei_txe_hw *hw = to_txe_hw(dev);
-	int t = 0;
+	ktime_t stop, start;
 
+	start = ktime_get();
+	stop = ktime_add(start, ms_to_ktime(SEC_ALIVENESS_WAIT_TIMEOUT));
 	do {
 		hw->aliveness = mei_txe_aliveness_get(dev);
 		if (hw->aliveness == expected) {
 			dev->pg_event = MEI_PG_EVENT_IDLE;
-			dev_dbg(dev->dev,
-				"aliveness settled after %d msecs\n", t);
-			return t;
+			dev_dbg(dev->dev, "aliveness settled after %lld usecs\n",
+				ktime_to_us(ktime_sub(ktime_get(), start)));
+			return 0;
 		}
-		mutex_unlock(&dev->device_lock);
-		msleep(MSEC_PER_SEC / 5);
-		mutex_lock(&dev->device_lock);
-		t += MSEC_PER_SEC / 5;
-	} while (t < SEC_ALIVENESS_WAIT_TIMEOUT);
+		usleep_range(20, 50);
+	} while (ktime_before(ktime_get(), stop));
 
 	dev->pg_event = MEI_PG_EVENT_IDLE;
 	dev_err(dev->dev, "aliveness timed out\n");
-- 
2.4.1