From: Joakim Zhang qiangqing.zhang@nxp.com
commit 5f186c257fa4808bb7f14e643b9fba3e11f08a30 upstream.
To enter stop mode, the CPU should manually assert a global Stop Mode request and check the acknowledgment asserted by FlexCAN. The CPU must only consider the FlexCAN in stop mode when both request and acknowledgment conditions are satisfied.
Fixes: de3578c198c6 ("can: flexcan: add self wakeup support") Reported-by: Marc Kleine-Budde mkl@pengutronix.de 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 Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/net/can/flexcan.c | 31 +++++++++++++++++++++++++++---- 1 file changed, 27 insertions(+), 4 deletions(-)
--- a/drivers/net/can/flexcan.c +++ b/drivers/net/can/flexcan.c @@ -400,9 +400,10 @@ static void flexcan_enable_wakeup_irq(st priv->write(reg_mcr, ®s->mcr); }
-static inline void flexcan_enter_stop_mode(struct flexcan_priv *priv) +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(®s->mcr); @@ -412,20 +413,37 @@ static inline void flexcan_enter_stop_mo /* enable stop request */ 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; }
-static inline void flexcan_exit_stop_mode(struct flexcan_priv *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(®s->mcr); reg_mcr &= ~FLEXCAN_MCR_SLF_WAK; priv->write(reg_mcr, ®s->mcr); + + return 0; }
static inline void flexcan_error_irq_enable(const struct flexcan_priv *priv) @@ -1612,7 +1630,9 @@ static int __maybe_unused flexcan_suspen */ if (device_may_wakeup(device)) { enable_irq_wake(dev->irq); - flexcan_enter_stop_mode(priv); + err = flexcan_enter_stop_mode(priv); + if (err) + return err; } else { err = flexcan_chip_disable(priv); if (err) @@ -1662,10 +1682,13 @@ static int __maybe_unused flexcan_noirq_ { struct net_device *dev = dev_get_drvdata(device); struct flexcan_priv *priv = netdev_priv(dev); + int err;
if (netif_running(dev) && device_may_wakeup(device)) { flexcan_enable_wakeup_irq(priv, false); - flexcan_exit_stop_mode(priv); + err = flexcan_exit_stop_mode(priv); + if (err) + return err; }
return 0;