From: Joakim Zhang qiangqing.zhang@nxp.com

Stop Mode is entered when Stop Mode is requested at chip level and MCR[LPM_ACK] is asserted by the FlexCAN.

Double check with IP owner, the MCR[LPM_ACK] bit should be polled for stop mode acknowledgment, not the acknowledgment from chip level which is used to gate flexcan clocks.

This patch depends on:

b7603d080ffc ("can: flexcan: add low power enter/exit acknowledgment helper")

Fixes: 5f186c257fa4 (can: flexcan: fix stop mode acknowledgment) Tested-by: Sean Nyekjaer sean@geanix.com Signed-off-by: Joakim Zhang qiangqing.zhang@nxp.com Cc: linux-stable stable@vger.kernel.org # >= v5.0 Signed-off-by: Marc Kleine-Budde mkl@pengutronix.de --- drivers/net/can/flexcan.c | 17 ++--------------- 1 file changed, 2 insertions(+), 15 deletions(-)

diff --git a/drivers/net/can/flexcan.c b/drivers/net/can/flexcan.c index 9f3a5e56fc37..94d10ec954a0 100644 --- a/drivers/net/can/flexcan.c +++ b/drivers/net/can/flexcan.c @@ -435,7 +435,6 @@ static void flexcan_enable_wakeup_irq(struct flexcan_priv *priv, bool enable) static inline int flexcan_enter_stop_mode(struct flexcan_priv *priv) { struct flexcan_regs __iomem *regs = priv->regs; - unsigned int ackval; u32 reg_mcr;

reg_mcr = priv->read(&regs->mcr); @@ -446,36 +445,24 @@ static inline int flexcan_enter_stop_mode(struct flexcan_priv *priv) regmap_update_bits(priv->stm.gpr, priv->stm.req_gpr, 1 << priv->stm.req_bit, 1 << priv->stm.req_bit);

- /* get stop acknowledgment */ - if (regmap_read_poll_timeout(priv->stm.gpr, priv->stm.ack_gpr, - ackval, ackval & (1 << priv->stm.ack_bit), - 0, FLEXCAN_TIMEOUT_US)) - return -ETIMEDOUT; - - return 0; + return flexcan_low_power_enter_ack(priv); }

static inline int flexcan_exit_stop_mode(struct flexcan_priv *priv) { struct flexcan_regs __iomem *regs = priv->regs; - unsigned int ackval; u32 reg_mcr;

/* remove stop request */ regmap_update_bits(priv->stm.gpr, priv->stm.req_gpr, 1 << priv->stm.req_bit, 0);

- /* get stop acknowledgment */ - if (regmap_read_poll_timeout(priv->stm.gpr, priv->stm.ack_gpr, - ackval, !(ackval & (1 << priv->stm.ack_bit)), - 0, FLEXCAN_TIMEOUT_US)) - return -ETIMEDOUT;

reg_mcr = priv->read(&regs->mcr); reg_mcr &= ~FLEXCAN_MCR_SLF_WAK; priv->write(reg_mcr, &regs->mcr);

- return 0; + return flexcan_low_power_exit_ack(priv); }

static inline void flexcan_error_irq_enable(const struct flexcan_priv *priv)