Merge branch 'mailbox-for-next' of git://git.linaro.org/landing-teams/working/fujitsu/integration

Pull mailbox updates from Jassi Brar:
 "Mainly we move from jiffy based timer to HRTIMER for finer control
  over polling.  Then a controller reduces its polling period from 10 to
  1ms"

* 'mailbox-for-next' of git://git.linaro.org/landing-teams/working/fujitsu/integration:
  mailbox: arm_mhu: reduce txpoll_period from 10ms to 1 ms
  mailbox: switch to hrtimer for tx_complete polling
  mailbox: Drop owner assignment from platform_driver

drivers/mailbox/arm_mhu.c

@@ -148,7 +148,7 @@ static int mhu_probe(struct amba_device *adev, const struct amba_id *id)
 	mhu->mbox.ops = &mhu_ops;
 	mhu->mbox.txdone_irq = false;
 	mhu->mbox.txdone_poll = true;
-	mhu->mbox.txpoll_period = 10;
+	mhu->mbox.txpoll_period = 1;
 
 	amba_set_drvdata(adev, mhu);
 

drivers/mailbox/bcm2835-mailbox.c

@@ -204,7 +204,6 @@ MODULE_DEVICE_TABLE(of, bcm2835_mbox_of_match);
 static struct platform_driver bcm2835_mbox_driver = {
 	.driver = {
 		.name = "bcm2835-mbox",
-		.owner = THIS_MODULE,
 		.of_match_table = bcm2835_mbox_of_match,
 	},
 	.probe		= bcm2835_mbox_probe,

drivers/mailbox/mailbox.c

@@ -26,8 +26,6 @@
 static LIST_HEAD(mbox_cons);
 static DEFINE_MUTEX(con_mutex);
 
-static void poll_txdone(unsigned long data);
-
 static int add_to_rbuf(struct mbox_chan *chan, void *mssg)
 {
 	int idx;
@@ -88,7 +86,9 @@ exit:
 	spin_unlock_irqrestore(&chan->lock, flags);
 
 	if (!err && (chan->txdone_method & TXDONE_BY_POLL))
-		poll_txdone((unsigned long)chan->mbox);
+		/* kick start the timer immediately to avoid delays */
+		hrtimer_start(&chan->mbox->poll_hrt, ktime_set(0, 0),
+			      HRTIMER_MODE_REL);
 }
 
 static void tx_tick(struct mbox_chan *chan, int r)
@@ -112,9 +112,10 @@ static void tx_tick(struct mbox_chan *chan, int r)
 		complete(&chan->tx_complete);
 }
 
-static void poll_txdone(unsigned long data)
+static enum hrtimer_restart txdone_hrtimer(struct hrtimer *hrtimer)
 {
-	struct mbox_controller *mbox = (struct mbox_controller *)data;
+	struct mbox_controller *mbox =
+		container_of(hrtimer, struct mbox_controller, poll_hrt);
 	bool txdone, resched = false;
 	int i;
 
@@ -130,9 +131,11 @@ static void poll_txdone(unsigned long data)
 		}
 	}
 
-	if (resched)
-		mod_timer(&mbox->poll, jiffies +
-				msecs_to_jiffies(mbox->txpoll_period));
+	if (resched) {
+		hrtimer_forward_now(hrtimer, ms_to_ktime(mbox->txpoll_period));
+		return HRTIMER_RESTART;
+	}
+	return HRTIMER_NORESTART;
 }
 
 /**
@@ -451,9 +454,9 @@ int mbox_controller_register(struct mbox_controller *mbox)
 		txdone = TXDONE_BY_ACK;
 
 	if (txdone == TXDONE_BY_POLL) {
-		mbox->poll.function = &poll_txdone;
-		mbox->poll.data = (unsigned long)mbox;
-		init_timer(&mbox->poll);
+		hrtimer_init(&mbox->poll_hrt, CLOCK_MONOTONIC,
+			     HRTIMER_MODE_REL);
+		mbox->poll_hrt.function = txdone_hrtimer;
 	}
 
 	for (i = 0; i < mbox->num_chans; i++) {
@@ -495,7 +498,7 @@ void mbox_controller_unregister(struct mbox_controller *mbox)
 		mbox_free_channel(&mbox->chans[i]);
 
 	if (mbox->txdone_poll)
-		del_timer_sync(&mbox->poll);
+		hrtimer_cancel(&mbox->poll_hrt);
 
 	mutex_unlock(&con_mutex);
 }

include/linux/mailbox_controller.h

@@ -9,7 +9,7 @@
 
 #include <linux/of.h>
 #include <linux/types.h>
-#include <linux/timer.h>
+#include <linux/hrtimer.h>
 #include <linux/device.h>
 #include <linux/completion.h>
 
@@ -67,7 +67,8 @@ struct mbox_chan_ops {
  * @txpoll_period:	If 'txdone_poll' is in effect, the API polls for
  *			last TX's status after these many millisecs
  * @of_xlate:		Controller driver specific mapping of channel via DT
- * @poll:		API private. Used to poll for TXDONE on all channels.
+ * @poll_hrt:		API private. hrtimer used to poll for TXDONE on all
+ *			channels.
  * @node:		API private. To hook into list of controllers.
  */
 struct mbox_controller {
@@ -81,7 +82,7 @@ struct mbox_controller {
 	struct mbox_chan *(*of_xlate)(struct mbox_controller *mbox,
 				      const struct of_phandle_args *sp);
 	/* Internal to API */
-	struct timer_list poll;
+	struct hrtimer poll_hrt;
 	struct list_head node;
 };