Commit 03336519 authored by J.D. Schroeder's avatar J.D. Schroeder Committed by Marc Kleine-Budde

can: c_can: Fix default pinmux glitch at init

The previous change 3973c526 (net: can: c_can: Disable pins when CAN
interface is down) causes a slight glitch on the pinctrl settings when used.
Since commit ab78029e (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: default avatarJ.D. Schroeder <jay.schroeder@garmin.com>
Signed-off-by: default avatarRoger Quadros <rogerq@ti.com>
Reviewed-by: default avatarGrygorii Strashko <grygorii.strashko@ti.com>
Cc: linux-stable <stable@vger.kernel.org>
Signed-off-by: default avatarMarc Kleine-Budde <mkl@pengutronix.de>
parent 585bc2ac
...@@ -592,6 +592,7 @@ static int c_can_start(struct net_device *dev) ...@@ -592,6 +592,7 @@ static int c_can_start(struct net_device *dev)
{ {
struct c_can_priv *priv = netdev_priv(dev); struct c_can_priv *priv = netdev_priv(dev);
int err; int err;
struct pinctrl *p;
/* basic c_can configuration */ /* basic c_can configuration */
err = c_can_chip_config(dev); err = c_can_chip_config(dev);
...@@ -604,8 +605,13 @@ static int c_can_start(struct net_device *dev) ...@@ -604,8 +605,13 @@ static int c_can_start(struct net_device *dev)
priv->can.state = CAN_STATE_ERROR_ACTIVE; priv->can.state = CAN_STATE_ERROR_ACTIVE;
/* activate pins */ /* Attempt to use "active" if available else use "default" */
pinctrl_pm_select_default_state(dev->dev.parent); p = pinctrl_get_select(priv->device, "active");
if (!IS_ERR(p))
pinctrl_put(p);
else
pinctrl_pm_select_default_state(priv->device);
return 0; return 0;
} }
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment