* [PATCH] can: flexcan: fix stop mode acknowledgment
@ 2019-06-11 6:47 Joakim Zhang
2019-06-17 12:57 ` Marc Kleine-Budde
0 siblings, 1 reply; 2+ messages in thread
From: Joakim Zhang @ 2019-06-11 6:47 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>
---
drivers/net/can/flexcan.c | 47 ++++++++++++++++++++++++++++++++-------
1 file changed, 39 insertions(+), 8 deletions(-)
diff --git a/drivers/net/can/flexcan.c b/drivers/net/can/flexcan.c
index e35083ff31ee..282dac1d8f5c 100644
--- a/drivers/net/can/flexcan.c
+++ b/drivers/net/can/flexcan.c
@@ -404,9 +404,11 @@ 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 timeout = FLEXCAN_TIMEOUT_US / 10;
+ unsigned int ackval;
u32 reg_mcr;
reg_mcr = priv->read(®s->mcr);
@@ -416,20 +418,48 @@ 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 */
+ regmap_read(priv->stm.gpr, priv->stm.ack_gpr, &ackval);
+
+ while (timeout-- && !(ackval & (1 << priv->stm.ack_bit))) {
+ udelay(10);
+ regmap_read(priv->stm.gpr, priv->stm.ack_gpr, &ackval);
+ }
+
+ if (!(ackval & (1 << priv->stm.ack_bit)))
+ 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 timeout = FLEXCAN_TIMEOUT_US / 10;
+ 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 */
+ regmap_read(priv->stm.gpr, priv->stm.ack_gpr, &ackval);
+
+ while (timeout-- && (ackval & (1 << priv->stm.ack_bit))) {
+ udelay(10);
+ regmap_read(priv->stm.gpr, priv->stm.ack_gpr, &ackval);
+ }
+
+ if (ackval & (1 << priv->stm.ack_bit))
+ return -ETIMEDOUT;
+
+ return 0;
}
static inline void flexcan_error_irq_enable(const struct flexcan_priv *priv)
@@ -1652,7 +1682,7 @@ 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 +1755,14 @@ 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
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH] can: flexcan: fix stop mode acknowledgment
2019-06-11 6:47 [PATCH] can: flexcan: fix stop mode acknowledgment Joakim Zhang
@ 2019-06-17 12:57 ` Marc Kleine-Budde
0 siblings, 0 replies; 2+ messages in thread
From: Marc Kleine-Budde @ 2019-06-17 12:57 UTC (permalink / raw)
To: Joakim Zhang, linux-can; +Cc: dl-linux-imx, wg, netdev
[-- Attachment #1.1: Type: text/plain, Size: 1977 bytes --]
On 6/11/19 8:47 AM, Joakim Zhang wrote:
> 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>
> ---
> drivers/net/can/flexcan.c | 47 ++++++++++++++++++++++++++++++++-------
> 1 file changed, 39 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/net/can/flexcan.c b/drivers/net/can/flexcan.c
> index e35083ff31ee..282dac1d8f5c 100644
> --- a/drivers/net/can/flexcan.c
> +++ b/drivers/net/can/flexcan.c
> @@ -404,9 +404,11 @@ 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 timeout = FLEXCAN_TIMEOUT_US / 10;
> + unsigned int ackval;
> u32 reg_mcr;
>
> reg_mcr = priv->read(®s->mcr);
> @@ -416,20 +418,48 @@ 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 */
> + regmap_read(priv->stm.gpr, priv->stm.ack_gpr, &ackval);
Please make use of regmap_read_poll_timeout().
Marc
--
Pengutronix e.K. | Marc Kleine-Budde |
Industrial Linux Solutions | Phone: +49-231-2826-924 |
Vertretung West/Dortmund | Fax: +49-5121-206917-5555 |
Amtsgericht Hildesheim, HRA 2686 | http://www.pengutronix.de |
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