* [PATCH V2] can: flexcan: fix stop mode acknowledgment
@ 2019-06-18 5:02 Joakim Zhang
0 siblings, 0 replies; only message in thread
From: Joakim Zhang @ 2019-06-18 5:02 UTC (permalink / raw)
To: mkl, linux-can; +Cc: dl-linux-imx, wg, netdev, Joakim Zhang
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>
ChangeLog:
V1->V2:
* regmap_read()-->regmap_read_poll_timeout()
---
drivers/net/can/flexcan.c | 35 +++++++++++++++++++++++++++--------
1 file changed, 27 insertions(+), 8 deletions(-)
diff --git a/drivers/net/can/flexcan.c b/drivers/net/can/flexcan.c
index e35083ff31ee..43245a5655c7 100644
--- a/drivers/net/can/flexcan.c
+++ b/drivers/net/can/flexcan.c
@@ -404,9 +404,10 @@ static void flexcan_enable_wakeup_irq(struct flexcan_priv *priv, bool enable)
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);
@@ -416,20 +417,37 @@ static inline void flexcan_enter_stop_mode(struct flexcan_priv *priv)
/* 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;
+ reg_mcr = priv->read(®s->mcr);
+ reg_mcr &= ~FLEXCAN_MCR_SLF_WAK;
+ priv->write(reg_mcr, ®s->mcr);
+
/* remove stop request */
regmap_update_bits(priv->stm.gpr, priv->stm.req_gpr,
1 << priv->stm.req_bit, 0);
- reg_mcr = priv->read(®s->mcr);
- reg_mcr &= ~FLEXCAN_MCR_SLF_WAK;
- priv->write(reg_mcr, ®s->mcr);
+ /* 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_error_irq_enable(const struct flexcan_priv *priv)
@@ -1652,7 +1670,7 @@ static int __maybe_unused flexcan_suspend(struct device *device)
*/
if (device_may_wakeup(device)) {
enable_irq_wake(dev->irq);
- flexcan_enter_stop_mode(priv);
+ err = flexcan_enter_stop_mode(priv);
} else {
err = flexcan_chip_disable(priv);
if (err)
@@ -1725,13 +1743,14 @@ static int __maybe_unused flexcan_noirq_resume(struct device *device)
{
struct net_device *dev = dev_get_drvdata(device);
struct flexcan_priv *priv = netdev_priv(dev);
+ int err = 0;
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);
}
- return 0;
+ return err;
}
static const struct dev_pm_ops flexcan_pm_ops = {
--
2.17.1
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