On 12/17/19 11:42 AM, Grygorii Strashko wrote:
>
>
> On 17/12/2019 12:07, Marek Vasut wrote:
>> The current code 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_m_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
>> pinctrl_get_select() falls back to using the "default" pinctrl state.
>>
>> Fixes: c9b3bce18da4 ("can: m_can: select pinctrl state in each
>> suspend/resume function")
>> Signed-off-by: Marek Vasut <marex@xxxxxxx>
>> Cc: Bich Hemon <bich.hemon@xxxxxx>
>> Cc: Grygorii Strashko <grygorii.strashko@xxxxxx>
>> Cc: J.D. Schroeder <jay.schroeder@xxxxxxxxxx>
>> Cc: Marc Kleine-Budde <mkl@xxxxxxxxxxxxxx>
>> Cc: Roger Quadros <rogerq@xxxxxx>
>> Cc: linux-stable <stable@xxxxxxxxxxxxxxx>
>> To: linux-can@xxxxxxxxxxxxxxx
>> ---
>> NOTE: This is commit 033365191136 ("can: c_can: Fix default pinmux
>> glitch at init")
>> adapted for m_can driver.
>> ---
>> drivers/net/can/m_can/m_can.c | 8 ++++++++
>> 1 file changed, 8 insertions(+)
>>
>> diff --git a/drivers/net/can/m_can/m_can.c
>> b/drivers/net/can/m_can/m_can.c
>> index 02c5795b73936..afb6760b17427 100644
>> --- a/drivers/net/can/m_can/m_can.c
>> +++ b/drivers/net/can/m_can/m_can.c
>> @@ -1243,12 +1243,20 @@ static void m_can_chip_config(struct
>> net_device *dev)
>> static void m_can_start(struct net_device *dev)
>> {
>> struct m_can_classdev *cdev = netdev_priv(dev);
>> + struct pinctrl *p;
>> /* basic m_can configuration */
>> m_can_chip_config(dev);
>> cdev->can.state = CAN_STATE_ERROR_ACTIVE;
>> + /* Attempt to use "active" if available else use "default" */
>> + p = pinctrl_get_select(cdev->dev, "active");
>> + if (!IS_ERR(p))
>> + pinctrl_put(p);
>> + else
>> + pinctrl_pm_select_default_state(cdev->dev);
>> +
>> m_can_enable_all_interrupts(cdev);
>> }
>>
>
> May be init state should be used - #define PINCTRL_STATE_INIT "init"
> instead?
I'm not sure I quite understand -- how ?
