Commit 048e3a34 authored by Joakim Zhang's avatar Joakim Zhang Committed by Marc Kleine-Budde
Browse files

can: flexcan: poll MCR_LPM_ACK instead of GPR ACK for stop mode acknowledgment 



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:

    b7603d08 ("can: flexcan: add low power enter/exit acknowledgment helper")

Fixes: 5f186c25 (can: flexcan: fix stop mode acknowledgment)
Tested-by: default avatarSean Nyekjaer <sean@geanix.com>
Signed-off-by: default avatarJoakim Zhang <qiangqing.zhang@nxp.com>
Cc: linux-stable <stable@vger.kernel.org> # >= v5.0
Signed-off-by: default avatarMarc Kleine-Budde <mkl@pengutronix.de>
parent b7603d08

drivers/net/can/flexcan.c

+2 −15
Original line number Diff line number Diff line
@@ -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)

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