On 07/31/2015 04:10 AM, Sasha Levin wrote:
> From: Heiko Carstens <heiko.carstens@xxxxxxxxxx>
>
> This patch has been added to the 3.18 stable tree. If you have any
> objections, please let us know.
>
> ===============
>
> [ Upstream commit 033365191136c97f88c81b7bd0011414db28bb4e ]
>
> 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@xxxxxxxxxx>
> Signed-off-by: Roger Quadros <rogerq@xxxxxx>
> Reviewed-by: Grygorii Strashko <grygorii.strashko@xxxxxx>
> Cc: linux-stable <stable@xxxxxxxxxxxxxxx>
> Signed-off-by: Marc Kleine-Budde <mkl@xxxxxxxxxxxxxx>
> Signed-off-by: Sasha Levin <sasha.levin@xxxxxxxxxx>
> ---
> arch/s390/kernel/process.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/s390/kernel/process.c b/arch/s390/kernel/process.c
> index ed84cc2..9b72e68 100644
> --- a/arch/s390/kernel/process.c
> +++ b/arch/s390/kernel/process.c
> @@ -171,7 +171,7 @@ asmlinkage void execve_tail(void)
> {
> current->thread.fp_regs.fpc = 0;
> if (MACHINE_HAS_IEEE)
> - asm volatile("sfpc %0,%0" : : "d" (0));
> + asm volatile("sfpc %0" : : "d" (0));
> }
>
> /*
>
The original upstream patch looked like this:
diff --git a/drivers/net/can/c_can/c_can.c b/drivers/net/can/c_can/c_can.c
index 041525d2595c..5d214d135332 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);
+
return 0;
}
Marc
--
Pengutronix e.K. | Marc Kleine-Budde |
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