Patch "mailbox: bcm-flexrm-mailbox: Fix FlexRM ring flush sequence" has been added to the 4.14-stable tree

[<gregkh@linuxfoundation.org>]

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

    mailbox: bcm-flexrm-mailbox: Fix FlexRM ring flush sequence

to the 4.14-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     mailbox-bcm-flexrm-mailbox-fix-flexrm-ring-flush-sequence.patch
and it can be found in the queue-4.14 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From a371c10ea4b38a5f120e86d906d404d50a0f4660 Mon Sep 17 00:00:00 2001
From: Anup Patel <anup.patel@broadcom.com>
Date: Tue, 3 Oct 2017 10:51:48 +0530
Subject: mailbox: bcm-flexrm-mailbox: Fix FlexRM ring flush sequence

From: Anup Patel <anup.patel@broadcom.com>

commit a371c10ea4b38a5f120e86d906d404d50a0f4660 upstream.

As-per suggestion from FlexRM HW folks, we have to first set
FlexRM ring flush state and then clear it for FlexRM ring flush
to work properly.

Currently, the FlexRM driver has incomplete FlexRM ring flush
sequence which causes repeated insmod+rmmod of mailbox client
drivers to fail.

This patch fixes FlexRM ring flush sequence in flexrm_shutdown()
as described above.

Fixes: dbc049eee730 ("mailbox: Add driver for Broadcom FlexRM
ring manager")

Signed-off-by: Anup Patel <anup.patel@broadcom.com>
Reviewed-by: Scott Branden <scott.branden@broadcom.com>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/mailbox/bcm-flexrm-mailbox.c |   22 +++++++++++++++++++---
 1 file changed, 19 insertions(+), 3 deletions(-)

--- a/drivers/mailbox/bcm-flexrm-mailbox.c
+++ b/drivers/mailbox/bcm-flexrm-mailbox.c
@@ -1365,8 +1365,8 @@ static void flexrm_shutdown(struct mbox_
 	/* Disable/inactivate ring */
 	writel_relaxed(0x0, ring->regs + RING_CONTROL);
 
-	/* Flush ring with timeout of 1s */
-	timeout = 1000;
+	/* Set ring flush state */
+	timeout = 1000; /* timeout of 1s */
 	writel_relaxed(BIT(CONTROL_FLUSH_SHIFT),
 			ring->regs + RING_CONTROL);
 	do {
@@ -1374,7 +1374,23 @@ static void flexrm_shutdown(struct mbox_
 		    FLUSH_DONE_MASK)
 			break;
 		mdelay(1);
-	} while (timeout--);
+	} while (--timeout);
+	if (!timeout)
+		dev_err(ring->mbox->dev,
+			"setting ring%d flush state timedout\n", ring->num);
+
+	/* Clear ring flush state */
+	timeout = 1000; /* timeout of 1s */
+	writel_relaxed(0x0, ring + RING_CONTROL);
+	do {
+		if (!(readl_relaxed(ring + RING_FLUSH_DONE) &
+		      FLUSH_DONE_MASK))
+			break;
+		mdelay(1);
+	} while (--timeout);
+	if (!timeout)
+		dev_err(ring->mbox->dev,
+			"clearing ring%d flush state timedout\n", ring->num);
 
 	/* Abort all in-flight requests */
 	for (reqid = 0; reqid < RING_MAX_REQ_COUNT; reqid++) {


Patches currently in stable-queue which might be from anup.patel@broadcom.com are

queue-4.14/mailbox-bcm-flexrm-mailbox-fix-flexrm-ring-flush-sequence.patch