Commit ae7b7ed5 authored by Angelo Dureghello's avatar Angelo Dureghello Committed by Zheng Zengkai
Browse files

can: flexcan: flexcan_chip_freeze(): fix chip freeze for missing bitrate 

stable inclusion
from stable-5.10.27
commit af3e6c3dcf5407ef98acd51c9faa727ed25e15c2
bugzilla: 51493

--------------------------------

[ Upstream commit 47c5e474 ]

For cases when flexcan is built-in, bitrate is still not set at
registering. So flexcan_chip_freeze() generates:

[    1.860000] *** ZERO DIVIDE ***   FORMAT=4
[    1.860000] Current process id is 1
[    1.860000] BAD KERNEL TRAP: 00000000
[    1.860000] PC: [<402e70c8>] flexcan_chip_freeze+0x1a/0xa8

To allow chip freeze, using an hardcoded timeout when bitrate is still
not set.

Fixes: ec15e27c ("can: flexcan: enable RX FIFO after FRZ/HALT valid")
Link: https://lore.kernel.org/r/20210315231510.650593-1-angelo@kernel-space.org


Signed-off-by: default avatarAngelo Dureghello <angelo@kernel-space.org>
[mkl: use if instead of ? operator]
Signed-off-by: default avatarMarc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: default avatarSasha Levin <sashal@kernel.org>

Signed-off-by: default avatarChen Jun <chenjun102@huawei.com>
Acked-by: default avatar&nbsp; Weilong Chen <chenweilong@huawei.com>
Signed-off-by: default avatarZheng Zengkai <zhengzengkai@huawei.com>
parent 5a085cd4

drivers/net/can/flexcan.c

+7 −1
Original line number Diff line number Diff line
@@ -658,9 +658,15 @@ static int flexcan_chip_disable(struct flexcan_priv *priv) 
static int flexcan_chip_freeze(struct flexcan_priv *priv)

{

	struct flexcan_regs __iomem *regs = priv->regs;

	unsigned int timeout = 1000 * 1000 * 10 / priv->can.bittiming.bitrate;

	unsigned int timeout;

	u32 bitrate = priv->can.bittiming.bitrate;

	u32 reg;



	if (bitrate)

		timeout = 1000 * 1000 * 10 / bitrate;

	else

		timeout = FLEXCAN_TIMEOUT_US / 10;



	reg = priv->read(&regs->mcr);

	reg |= FLEXCAN_MCR_FRZ | FLEXCAN_MCR_HALT;

	priv->write(reg, &regs->mcr);