On 27/11/14 23:19, Marc Kleine-Budde wrote:

On 11/27/2014 02:26 PM, Linus Walleij wrote:

quoted

On Fri, Nov 14, 2014 at 4:40 PM, Roger Quadros [off-list ref] wrote:

quoted

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 <redacted>

Reviewed-by: Linus Walleij <redacted>

Thanks, however the patch is already upstream.

quoted

I see you figured it out all by yourselves :D

(Sorry for being absent.)

quoted

+#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.

Roger, you can prepare a patch, if needed.

As pinctrl sleep is an optional driver feature we don't need to do any changes.
For the DRA7 specific case, the platform configs ensure that PM is enabled.

cheers,
-roger