On 11/27/2014 11:47 PM, Sören Brinkmann wrote:
> On Thu, 2014-11-27 at 10:17PM +0100, Marc Kleine-Budde wrote:
>> On 11/27/2014 02:08 PM, Kedareswara rao Appana wrote:
>>> Instead of enabling/disabling clocks at several locations in the driver,
>>> use the runtime_pm framework. This consolidates the actions for
>>> runtime PM in the appropriate callbacks and makes the driver more
>>> readable and mantainable.
>>>
>>> Signed-off-by: Soren Brinkmann <soren.brinkmann@xxxxxxxxxx>
>>> Signed-off-by: Kedareswara rao Appana <appanad@xxxxxxxxxx>
>>> ---
>>> Changes for v3:
>>> - Converted the driver to use runtime_pm.
>>> Changes for v2:
>>> - Removed the struct platform_device* from suspend/resume
>>> as suggest by Lothar.
>>>
>>> drivers/net/can/xilinx_can.c | 119 +++++++++++++++++++++++++----------------
>>> 1 files changed, 72 insertions(+), 47 deletions(-)
>>>
>>> diff --git a/drivers/net/can/xilinx_can.c b/drivers/net/can/xilinx_can.c
>>> index 8a998e3..1be28ed 100644
>>> --- a/drivers/net/can/xilinx_can.c
>>> +++ b/drivers/net/can/xilinx_can.c
> [...]
>>> @@ -1030,7 +1046,10 @@ static int __maybe_unused xcan_resume(struct device *dev)
>>> return 0;
>>> }
>>>
>>> -static SIMPLE_DEV_PM_OPS(xcan_dev_pm_ops, xcan_suspend, xcan_resume);
>>> +static const struct dev_pm_ops xcan_dev_pm_ops = {
>>> + SET_SYSTEM_SLEEP_PM_OPS(xcan_suspend, xcan_resume)
>>> + SET_PM_RUNTIME_PM_OPS(xcan_runtime_suspend, xcan_runtime_resume, NULL)
>>> +};
>>>
>>> /**
>>> * xcan_probe - Platform registration call
>>> @@ -1071,7 +1090,7 @@ static int xcan_probe(struct platform_device *pdev)
>>> return -ENOMEM;
>>>
>>> priv = netdev_priv(ndev);
>>> - priv->dev = ndev;
>>> + priv->dev = &pdev->dev;
>>> priv->can.bittiming_const = &xcan_bittiming_const;
>>> priv->can.do_set_mode = xcan_do_set_mode;
>>> priv->can.do_get_berr_counter = xcan_get_berr_counter;
>>> @@ -1137,6 +1156,11 @@ static int xcan_probe(struct platform_device *pdev)
>>>
>>> netif_napi_add(ndev, &priv->napi, xcan_rx_poll, rx_max);
>>>
>>> + pm_runtime_set_active(&pdev->dev);
>>> + pm_runtime_irq_safe(&pdev->dev);
>>
>> You use just clock_enable()/disable() in the runtime functions, thus you
>> can say they are irq_safe. On the other the the zync grpio driver uses
>> "full" prepare_enable/disable_unprepare calls. What's best practice here?
>
> IIRC, the prepare/unprepare functions can sleep. xcan_get_berr_counter
> is called from atomic context. So, I think we have to use the
> disable/enable functions without the prepare/unprepare.
> In the GPIO driver the that problem does not exist.
IC, yes, correct.
This is why we introducted in other drivers a __get_berr_counter()
function, that doesn't touch the clocks, which is used from within the
driver (from the atomic contects), while get_berr_counter() will fiddle
with the clocks. This function is used for the
priv->can.do_get_berr_counter callback.
Marc
--
Pengutronix e.K. | Marc Kleine-Budde |
Industrial Linux Solutions | Phone: +49-231-2826-924 |
Vertretung West/Dortmund | Fax: +49-5121-206917-5555 |
Amtsgericht Hildesheim, HRA 2686 | http://www.pengutronix.de |
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