lkml.org 
[lkml]   [2018]   [Jan]   [2]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    SubjectRe: [PATCH v6 3/6] can: m_can: Add PM Runtime
    From
    Date
    On 12/22/2017 02:31 PM, Faiz Abbas wrote:
    > From: Franklin S Cooper Jr <fcooper@ti.com>
    >
    > Add support for PM Runtime which is the new way to handle managing clocks.
    > However, to avoid breaking SoCs not using PM_RUNTIME leave the old clk
    > management approach in place.

    There is no PM_RUNTIME anymore since 464ed18ebdb6 ("PM: Eliminate
    CONFIG_PM_RUNTIME")

    Have a look at the discussion: https://patchwork.kernel.org/patch/9436507/ :

    >> Well, I admit it would be nicer if drivers didn't have to worry about
    >> whether or not CONFIG_PM was enabled. A slightly cleaner approach
    >> from the one outlined above would have the probe routine do this:
    >>
    >> my_power_up(dev);
    >> pm_runtime_set_active(dev);
    >> pm_runtime_get_noresume(dev);
    >> pm_runtime_enable(dev);

    > PM_RUNTIME is required by OMAP based devices to handle clock management.
    > Therefore, this allows future Texas Instruments SoCs that have the MCAN IP
    > to work with this driver.

    Who will set the SET_RUNTIME_PM_OPS in this case?

    > Signed-off-by: Franklin S Cooper Jr <fcooper@ti.com>
    > [nsekhar@ti.com: handle pm_runtime_get_sync() failure, fix some bugs]
    > Signed-off-by: Sekhar Nori <nsekhar@ti.com>
    > Signed-off-by: Faiz Abbas <faiz_abbas@ti.com>
    > ---
    > drivers/net/can/m_can/m_can.c | 38 ++++++++++++++++++++++++++++++++++----
    > 1 file changed, 34 insertions(+), 4 deletions(-)
    >
    > diff --git a/drivers/net/can/m_can/m_can.c b/drivers/net/can/m_can/m_can.c
    > index f72116e..53e764f 100644
    > --- a/drivers/net/can/m_can/m_can.c
    > +++ b/drivers/net/can/m_can/m_can.c
    > @@ -23,6 +23,7 @@
    > #include <linux/of.h>
    > #include <linux/of_device.h>
    > #include <linux/platform_device.h>
    > +#include <linux/pm_runtime.h>
    > #include <linux/iopoll.h>
    > #include <linux/can/dev.h>
    >
    > @@ -625,19 +626,33 @@ static int m_can_clk_start(struct m_can_priv *priv)
    > {
    > int err;
    >
    > + err = pm_runtime_get_sync(priv->device);
    > + if (err) {
    > + pm_runtime_put_noidle(priv->device);

    Why do you call this in case of an error?

    > + return err;
    > + }
    > +
    > err = clk_prepare_enable(priv->hclk);
    > if (err)
    > - return err;
    > + goto pm_runtime_put;
    >
    > err = clk_prepare_enable(priv->cclk);
    > if (err)
    > - clk_disable_unprepare(priv->hclk);
    > + goto disable_hclk;
    >
    > return err;
    > +
    > +disable_hclk:
    > + clk_disable_unprepare(priv->hclk);
    > +pm_runtime_put:
    > + pm_runtime_put_sync(priv->device);
    > + return err;
    > }
    >
    > static void m_can_clk_stop(struct m_can_priv *priv)
    > {
    > + pm_runtime_put_sync(priv->device);
    > +
    > clk_disable_unprepare(priv->cclk);
    > clk_disable_unprepare(priv->hclk);
    > }
    > @@ -1577,13 +1592,20 @@ static int m_can_plat_probe(struct platform_device *pdev)
    > /* Enable clocks. Necessary to read Core Release in order to determine
    > * M_CAN version
    > */
    > + pm_runtime_enable(&pdev->dev);
    > + ret = pm_runtime_get_sync(&pdev->dev);
    > + if (ret) {
    > + pm_runtime_put_noidle(&pdev->dev);

    Why do you call this in case of error?

    > + goto pm_runtime_fail;
    > + }
    > +
    > ret = clk_prepare_enable(hclk);
    > if (ret)
    > - goto disable_hclk_ret;
    > + goto pm_runtime_put;
    >
    > ret = clk_prepare_enable(cclk);
    > if (ret)
    > - goto disable_cclk_ret;
    > + goto disable_hclk_ret;
    >
    > res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "m_can");
    > addr = devm_ioremap_resource(&pdev->dev, res);
    > @@ -1666,6 +1688,11 @@ static int m_can_plat_probe(struct platform_device *pdev)
    > clk_disable_unprepare(cclk);
    > disable_hclk_ret:
    > clk_disable_unprepare(hclk);
    > +pm_runtime_put:
    > + pm_runtime_put_sync(&pdev->dev);
    > +pm_runtime_fail:
    > + if (ret)
    > + pm_runtime_disable(&pdev->dev);
    > failed_ret:
    > return ret;
    > }
    > @@ -1723,6 +1750,9 @@ static int m_can_plat_remove(struct platform_device *pdev)
    > struct net_device *dev = platform_get_drvdata(pdev);
    >
    > unregister_m_can_dev(dev);
    > +
    > + pm_runtime_disable(&pdev->dev);
    > +
    > platform_set_drvdata(pdev, NULL);
    >
    > free_m_can_dev(dev);
    >

    regards,
    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 |

    [unhandled content-type:application/pgp-signature]
    \
     
     \ /
      Last update: 2018-01-02 17:07    [W:4.320 / U:0.428 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site