Re: [PATCH v2 1/2] net: can: c_can: Fix default pinmux glitch at init

[Grygorii Strashko]

On 07/09/2015 01:59 PM, Marc Kleine-Budde wrote:
> On 07/09/2015 12:58 PM, Grygorii Strashko wrote:
> > On 07/08/2015 02:38 PM, Roger Quadros wrote:
> > > From: "J.D. Schroeder" <jay.schroeder@xxxxxxxxxx>
> > >
> > > 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>
> > > ---
> > >    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.
>
> Is this an Acked-by?

Not sure I can ack overall patch - is up to can driver maintainer
for this part Reviewed-by: Grygorii Strashko <grygorii.strashko@xxxxxx>

--
regards,
-grygorii
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