Messages in this thread | | | Date | Wed, 8 Jul 2015 11:13:23 +0300 | From | Roger Quadros <> | Subject | Re: [PATCH 1/2] net: can: c_can: Fix default pinmux glitch at init |
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On 07/07/15 18:49, Grygorii Strashko wrote: > On 07/07/2015 05:37 PM, Roger Quadros wrote: >> On 07/07/15 17:35, Roger Quadros wrote: >>> On 07/07/15 17:33, Marc Kleine-Budde wrote: >>>> On 07/07/2015 04:27 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 >>>>> >>>>> 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 | 13 ++++++++++++- >>>>> 1 file changed, 12 insertions(+), 1 deletion(-) >>>>> >>>>> diff --git a/drivers/net/can/c_can/c_can.c >>>>> b/drivers/net/can/c_can/c_can.c >>>>> index 041525d..66e98e7 100644 >>>>> --- a/drivers/net/can/c_can/c_can.c >>>>> +++ b/drivers/net/can/c_can/c_can.c >>>>> @@ -605,7 +605,18 @@ 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); >>>>> +#ifdef CONFIG_PINCTRL >>>> >>>> Please remove the ifdef, AFAICS there are static inline noop functions >>>> if CONFIG_PINCTRL switched off. >>> >>> yes, you are right. >> >> On second thoughts >> >> device->pins are not defined if CONFIG_PINCTRL is not set. >> so we can't remove the #ifdef. > > May be you can use [devm_]pinctrl_get?
Why should we do that? The device core has already done the pinctrl_get() and it is available in device->pins->p.
cheers, -roger
> >>>> >>>>> + if (priv->device->pins) { >>>>> + struct pinctrl_state *s; >>>>> + >>>>> + /* Attempt to use "active" if available else use "default" */ >>>>> + s = pinctrl_lookup_state(priv->device->pins->p, "active"); >>>>> + if (!IS_ERR(s)) >>>>> + pinctrl_select_state(priv->device->pins->p, s); >>>>> + else >>>>> + pinctrl_pm_select_default_state(dev->dev.parent); >>>>> + } >>>>> +#endif >>>>> return 0; >>>>> } >>>>> >
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