On 11/27/19 6:56 AM, Joakim Zhang wrote:
> CAN controller could be stucked in stop mode once it enters stop mode
^^^^^^^ stuck
> when suspend, and then it fails to exit stop mode when resume.
How can this happen?
> Only code reset can get CAN out of stop mode,
What is "code reset"?
> so add stop mode remove request during probe stage for other
> methods(soft reset from chip level, unbind/bind driver, etc) to let
^^^ please add a space
> CAN active again.
Can you rephrase the sentence after "so add stop mode remove request
during probe stage". I'm not completely sure what you want to tell.
> MCR[LPMACK] will be checked when enable CAN in
> register_flexcandev().
>
> Suggested-by: Sean Nyekjaer <sean@xxxxxxxxxx>
> Signed-off-by: Joakim Zhang <qiangqing.zhang@xxxxxxx>
> ------
> ChangeLog:
> V1->V2: new add.
> ---
> drivers/net/can/flexcan.c | 28 ++++++++++++++++++++++------
> 1 file changed, 22 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/net/can/flexcan.c b/drivers/net/can/flexcan.c
> index 2297663cacb2..5d5ed28d3005 100644
> --- a/drivers/net/can/flexcan.c
> +++ b/drivers/net/can/flexcan.c
> @@ -449,6 +449,13 @@ static inline int flexcan_exit_stop_mode(struct flexcan_priv *priv)
> return 0;
> }
>
> +static void flexcan_try_exit_stop_mode(struct flexcan_priv *priv)
> +{
> + /* remove stop request */
> + regmap_update_bits(priv->stm.gpr, priv->stm.req_gpr,
> + 1 << priv->stm.req_bit, 0);
> +}
> +
> static inline void flexcan_error_irq_enable(const struct flexcan_priv *priv)
> {
> struct flexcan_regs __iomem *regs = priv->regs;
> @@ -1649,6 +1656,21 @@ static int flexcan_probe(struct platform_device *pdev)
> priv->devtype_data = devtype_data;
> priv->reg_xceiver = reg_xceiver;
>
> + if (priv->devtype_data->quirks & FLEXCAN_QUIRK_SETUP_STOP_MODE) {
> + err = flexcan_setup_stop_mode(pdev);
> + if (err)
> + dev_dbg(&pdev->dev, "failed to setup stop-mode\n");
> +
> + /* CAN controller could be stucked in stop mode once it enters
> + * stop mode when suspend, and then it fails to exit stop
> + * mode when resume. Only code reset can get CAN out of stop
> + * mode, so add stop mode remove request here for other methods
> + * (soft reset, bind, etc) to let CAN active again. MCR[LPMACK]
> + * will be checked when enable CAN in register_flexcandev().
> + */
> + flexcan_try_exit_stop_mode(priv);
> + }
> +
> pm_runtime_get_noresume(&pdev->dev);
> pm_runtime_set_active(&pdev->dev);
> pm_runtime_enable(&pdev->dev);
> @@ -1661,12 +1683,6 @@ static int flexcan_probe(struct platform_device *pdev)
>
> devm_can_led_init(dev);
>
> - if (priv->devtype_data->quirks & FLEXCAN_QUIRK_SETUP_STOP_MODE) {
> - err = flexcan_setup_stop_mode(pdev);
> - if (err)
> - dev_dbg(&pdev->dev, "failed to setup stop-mode\n");
> - }
> -
> return 0;
>
> failed_register:
>
Marc
--
Pengutronix e.K. | Marc Kleine-Budde |
Embedded Linux | https://www.pengutronix.de |
Vertretung West/Dortmund | Phone: +49-231-2826-924 |
Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |
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