| Message ID | 5466225D.2070202@ti.com |
|---|---|
| State | Superseded |
| Headers | show |
On 11/14/2014 04:40 PM, Roger Quadros wrote: > DRA7 CAN IP suffers from a problem which causes it to be prevented > from fully turning OFF (i.e. stuck in transition) if the module was > disabled while there was traffic on the CAN_RX line. > > To work around this issue we select the SLEEP pin state by default > on probe and use the DEFAULT pin state on CAN up and back to the > SLEEP pin state on CAN down. > > Signed-off-by: Roger Quadros <rogerq@ti.com> Wow! Some interations later this patch got quite nice and shiny :) Applied all to can-next/master. Thanks, Marc
On 11/14/2014 05:49 PM, Marc Kleine-Budde wrote: > On 11/14/2014 04:40 PM, Roger Quadros wrote: >> DRA7 CAN IP suffers from a problem which causes it to be prevented >> from fully turning OFF (i.e. stuck in transition) if the module was >> disabled while there was traffic on the CAN_RX line. >> >> To work around this issue we select the SLEEP pin state by default >> on probe and use the DEFAULT pin state on CAN up and back to the >> SLEEP pin state on CAN down. >> >> Signed-off-by: Roger Quadros <rogerq@ti.com> > > Wow! Some interations later this patch got quite nice and shiny :) > Applied all to can-next/master. Thanks Marc :) cheers, -roger -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Fri, Nov 14, 2014 at 4:40 PM, Roger Quadros <rogerq@ti.com> wrote: > DRA7 CAN IP suffers from a problem which causes it to be prevented > from fully turning OFF (i.e. stuck in transition) if the module was > disabled while there was traffic on the CAN_RX line. > > To work around this issue we select the SLEEP pin state by default > on probe and use the DEFAULT pin state on CAN up and back to the > SLEEP pin state on CAN down. > > Signed-off-by: Roger Quadros <rogerq@ti.com> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> I see you figured it out all by yourselves :D (Sorry for being absent.) > +#include <linux/pinctrl/consumer.h> > + pinctrl_pm_select_default_state(dev->dev.parent); > + pinctrl_pm_select_sleep_state(dev->dev.parent); > + pinctrl_pm_select_sleep_state(dev->dev.parent); NB: in drivers/base/pinctrl.c: #ifdef CONFIG_PM /* * If power management is enabled, we also look for the optional * sleep and idle pin states, with semantics as defined in * <linux/pinctrl/pinctrl-state.h> */ dev->pins->sleep_state = pinctrl_lookup_state(dev->pins->p, PINCTRL_STATE_SLEEP); So if these states are necessary for the driver to work, put depends on PM or select PM in the Kconfig. Yours, Linus Walleij -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/net/can/c_can/c_can.c b/drivers/net/can/c_can/c_can.c index 8e78bb4..f94a9fa 100644 --- a/drivers/net/can/c_can/c_can.c +++ b/drivers/net/can/c_can/c_can.c @@ -35,6 +35,7 @@ #include <linux/list.h> #include <linux/io.h> #include <linux/pm_runtime.h> +#include <linux/pinctrl/consumer.h> #include <linux/can.h> #include <linux/can/dev.h> @@ -603,6 +604,8 @@ 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); return 0; } @@ -611,6 +614,9 @@ static void c_can_stop(struct net_device *dev) struct c_can_priv *priv = netdev_priv(dev); c_can_irq_control(priv, false); + + /* deactivate pins */ + pinctrl_pm_select_sleep_state(dev->dev.parent); priv->can.state = CAN_STATE_STOPPED; } @@ -1244,6 +1250,13 @@ int register_c_can_dev(struct net_device *dev) struct c_can_priv *priv = netdev_priv(dev); int err; + /* Deactivate pins to prevent DRA7 DCAN IP from being + * stuck in transition when module is disabled. + * Pins are activated in c_can_start() and deactivated + * in c_can_stop() + */ + pinctrl_pm_select_sleep_state(dev->dev.parent); + c_can_pm_runtime_enable(priv); dev->flags |= IFF_ECHO; /* we support local echo */
DRA7 CAN IP suffers from a problem which causes it to be prevented from fully turning OFF (i.e. stuck in transition) if the module was disabled while there was traffic on the CAN_RX line. To work around this issue we select the SLEEP pin state by default on probe and use the DEFAULT pin state on CAN up and back to the SLEEP pin state on CAN down. Signed-off-by: Roger Quadros <rogerq@ti.com> --- drivers/net/can/c_can/c_can.c | 13 +++++++++++++ 1 file changed, 13 insertions(+)