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SubjectRe: [PATCH v2 1/2] net: can: c_can: Fix default pinmux glitch at init
On 07/08/2015 02:38 PM, Roger Quadros wrote:
> From: "J.D. Schroeder" <jay.schroeder@garmin.com>
>
> The previous change 3973c526ae9c (net: can: c_can: Disable pins when CAN interface
> is down) causes a slight glitch on the pinctrl settings when used. Since
> commit ab78029 (drivers/pinctrl: grab default handles from device core),
> the device core will automatically set the default pins. This causes
> the pins to be momentarily set to the default and then to the sleep
> state in register_c_can_dev(). By adding an optional "enable" state,
> boards can set the default pin state to be disabled and avoid the
> glitch when the switch from default to sleep first occurs. If the
> "enable" state is not available c_can_pinctrl_select_state() falls
> back to using the "default" pinctrl state.
>
> [Roger Q] - Forward port to v4.2 and use pinctrl_get_select().
>
> Signed-off-by: J.D. Schroeder <jay.schroeder@garmin.com>
> Signed-off-by: Roger Quadros <rogerq@ti.com>
> ---
> drivers/net/can/c_can/c_can.c | 10 ++++++++--
> 1 file changed, 8 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/net/can/c_can/c_can.c b/drivers/net/can/c_can/c_can.c
> index 041525d..5d214d1 100644
> --- a/drivers/net/can/c_can/c_can.c
> +++ b/drivers/net/can/c_can/c_can.c
> @@ -592,6 +592,7 @@ static int c_can_start(struct net_device *dev)
> {
> struct c_can_priv *priv = netdev_priv(dev);
> int err;
> + struct pinctrl *p;
>
> /* basic c_can configuration */
> err = c_can_chip_config(dev);
> @@ -604,8 +605,13 @@ static int c_can_start(struct net_device *dev)
>
> priv->can.state = CAN_STATE_ERROR_ACTIVE;
>
> - /* activate pins */
> - pinctrl_pm_select_default_state(dev->dev.parent);
> + /* Attempt to use "active" if available else use "default" */
> + p = pinctrl_get_select(priv->device, "active");
> + if (!IS_ERR(p))
> + pinctrl_put(p);
> + else
> + pinctrl_pm_select_default_state(priv->device);
> +

Thanks. This part looks good to me now.

> return 0;
> }
>
>


--
regards,
-grygorii


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