On 01/13/2015 06:08 PM, Sören Brinkmann wrote:
> On Tue, 2015-01-13 at 12:08PM +0100, Marc Kleine-Budde wrote:
>> On 01/12/2015 07:45 PM, Sören Brinkmann wrote:
>>> On Mon, 2015-01-12 at 08:34PM +0530, 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 v5:
>>>> - Updated with the review comments.
>>>> Updated the remove fuction to use runtime_pm.
>>>> Chnages for v4:
>>>> - Updated with the review comments.
>>>> 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 | 157 ++++++++++++++++++++++++++++-------------
>>>> 1 files changed, 107 insertions(+), 50 deletions(-)
>>> [..]
>>>> +static int __maybe_unused xcan_runtime_resume(struct device *dev)
>>>> {
>>>> - struct platform_device *pdev = dev_get_drvdata(dev);
>>>> - struct net_device *ndev = platform_get_drvdata(pdev);
>>>> + struct net_device *ndev = dev_get_drvdata(dev);
>>>> struct xcan_priv *priv = netdev_priv(ndev);
>>>> int ret;
>>>> + u32 isr, status;
>>>>
>>>> ret = clk_enable(priv->bus_clk);
>>>> if (ret) {
>>>> @@ -1014,15 +1030,28 @@ static int __maybe_unused xcan_resume(struct device *dev)
>>>> ret = clk_enable(priv->can_clk);
>>>> if (ret) {
>>>> dev_err(dev, "Cannot enable clock.\n");
>>>> - clk_disable_unprepare(priv->bus_clk);
>>>> + clk_disable(priv->bus_clk);
>>> [...]
>>>> @@ -1173,12 +1219,23 @@ static int xcan_remove(struct platform_device *pdev)
>>>> {
>>>> struct net_device *ndev = platform_get_drvdata(pdev);
>>>> struct xcan_priv *priv = netdev_priv(ndev);
>>>> + int ret;
>>>> +
>>>> + ret = pm_runtime_get_sync(&pdev->dev);
>>>> + if (ret < 0) {
>>>> + netdev_err(ndev, "%s: pm_runtime_get failed(%d)\n",
>>>> + __func__, ret);
>>>> + return ret;
>>>> + }
>>>>
>>>> if (set_reset_mode(ndev) < 0)
>>>> netdev_err(ndev, "mode resetting failed!\n");
>>>>
>>>> unregister_candev(ndev);
>>>> + pm_runtime_disable(&pdev->dev);
>>>> netif_napi_del(&priv->napi);
>>>> + clk_disable_unprepare(priv->bus_clk);
>>>> + clk_disable_unprepare(priv->can_clk);
>>>
>>> Shouldn't pretty much all these occurrences of clk_disable/enable
>>> disappear? This should all be handled by the runtime_pm framework now.
>>
>> We have:
>> - clk_prepare_enable() in probe
>
> This should become something like pm_runtime_get_sync(), shouldn't it?
>
>> - clk_disable_unprepare() in remove
>
> pm_runtime_put()
>
>> - clk_enable() in runtime_resume
>> - clk_disable() in runtime_suspend
>
> These are the ones needed.
>
> The above makes me suspect that the clocks are always on, regardless of
Define "on" :)
The clocks are prepared after probe() exists, but not enabled. The first
pm_runtime_get_sync() will enable the clocks.
> the runtime suspend state since they are enabled in probe and disabled
> in remove, is that right? Ideally, the usage in probe and remove should
> be migrated to runtime_pm and clocks should really only be running when
> needed and not throughout the whole lifetime of the driver.
The clocks are not en/disabled via pm_runtime, because
pm_runtime_get_sync() is called from atomic contect. We can have another
look into the driver and try to change this.
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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