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From:   gregkh@linuxfoundation.org
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Joakim Zhang <qiangqing.zhang@nxp.com>,
        Marc Kleine-Budde <mkl@pengutronix.de>
Subject: [PATCH 5.4 010/168] can: flexcan: assert FRZ bit in flexcan_chip_freeze()
Date:   Mon, 15 Mar 2021 14:54:02 +0100
Message-Id: <20210315135550.683448596@linuxfoundation.org>
In-Reply-To: <20210315135550.333963635@linuxfoundation.org>
References: <20210315135550.333963635@linuxfoundation.org>
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From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

From: Joakim Zhang <qiangqing.zhang@nxp.com>

commit 449052cfebf624b670faa040245d3feed770d22f upstream.

Assert HALT bit to enter freeze mode, there is a premise that FRZ bit is
asserted. This patch asserts FRZ bit in flexcan_chip_freeze, although
the reset value is 1b'1. This is a prepare patch, later patch will
invoke flexcan_chip_freeze() to enter freeze mode, which polling freeze
mode acknowledge.

Fixes: b1aa1c7a2165b ("can: flexcan: fix transition from and to freeze mode in chip_{,un}freeze")
Link: https://lore.kernel.org/r/20210218110037.16591-2-qiangqing.zhang@nxp.com
Signed-off-by: Joakim Zhang <qiangqing.zhang@nxp.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/net/can/flexcan.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/net/can/flexcan.c
+++ b/drivers/net/can/flexcan.c
@@ -548,7 +548,7 @@ static int flexcan_chip_freeze(struct fl
 	u32 reg;
 
 	reg = priv->read(&regs->mcr);
-	reg |= FLEXCAN_MCR_HALT;
+	reg |= FLEXCAN_MCR_FRZ | FLEXCAN_MCR_HALT;
 	priv->write(reg, &regs->mcr);
 
 	while (timeout-- && !(priv->read(&regs->mcr) & FLEXCAN_MCR_FRZ_ACK))