The patch below does not apply to the 4.9-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 stable@vger.kernel.org.

thanks,

greg k-h

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

From 393753b217f05474e714aea36c37501546ed1202 Mon Sep 17 00:00:00 2001

From: Roman Fietze roman.fietze@telemotive.de 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.

Signed-off-by: Roman Fietze roman.fietze@telemotive.de Cc: linux-stable stable@vger.kernel.org Signed-off-by: Marc Kleine-Budde mkl@pengutronix.de

diff --git a/drivers/net/can/m_can/m_can.c b/drivers/net/can/m_can/m_can.c index b397a33f3d32..8e2b7f873c4d 100644 --- a/drivers/net/can/m_can/m_can.c +++ b/drivers/net/can/m_can/m_can.c @@ -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)