FAILED: patch "[PATCH] can: m_can.c: fix setup of CCCR register: clear CCCR NISO bit" failed to apply to 4.4-stable tree

The patch below does not apply to the 4.4-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From: Roman Fietze <[email protected]>
Date: Wed, 11 Jul 2018 15:36:14 +0200
Subject: [PATCH] can: m_can.c: fix setup of CCCR register: clear CCCR NISO bit
before checking can.ctrlmode

Inside m_can_chip_config(), when setting up the new value of the CCCR, the CCCR_NISO bit is not cleared like the others, CCCR_TEST, CCCR_MON, CCCR_BRSE and CCCR_FDOE, before checking the can.ctrlmode bits for CAN_CTRLMODE_FD_NON_ISO.

This way once the controller was configured for CAN_CTRLMODE_FD_NON_ISO, this mode could never be cleared again.

This fix is only relevant for controllers with version 3.1.x or 3.2.x. Older versions do not support NISO.

index b397a33f3d32..8e2b7f873c4d 100644
@@ -1109,7 +1109,8 @@ static void m_can_chip_config(struct net_device *dev)
 
 	} else {
 	/* Version 3.1.x or 3.2.x */
-		cccr &= ~(CCCR_TEST | CCCR_MON | CCCR_BRSE | CCCR_FDOE);
+		cccr &= ~(CCCR_TEST | CCCR_MON | CCCR_BRSE | CCCR_FDOE |
+			  CCCR_NISO);
 
 		/* Only 3.2.x has NISO Bit implemented */
 		if (priv->can.ctrlmode & CAN_CTRLMODE_FD_NON_ISO)