RE: [PATCH v7] can: xilinx: Convert to runtime_pm

From: Appana Durga Kedareswara Rao
Date: Mon Oct 26 2015 - 02:13:24 EST

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Previous message: Kedareswara rao Appana: "[PATCH v8] can: xilinx: Convert to runtime_pm"
In reply to: Marc Kleine-Budde: "Re: [PATCH v7] can: xilinx: Convert to runtime_pm"
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Hi Marc,

> -----Original Message-----
> From: Marc Kleine-Budde [mailto:mkl@xxxxxxxxxxxxxx]
> Sent: Monday, October 26, 2015 1:54 AM
> To: Appana Durga Kedareswara Rao; Anirudha Sarangi; wg@xxxxxxxxxxxxxx;
> Michal Simek; Soren Brinkmann
> Cc: linux-can@xxxxxxxxxxxxxxx; netdev@xxxxxxxxxxxxxxx; linux-arm-
> kernel@xxxxxxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; Appana Durga
> Kedareswara Rao
> Subject: Re: [PATCH v7] can: xilinx: Convert to runtime_pm
>
> On 10/23/2015 07:23 AM, 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: Kedareswara rao Appana <appanad@xxxxxxxxxx>
> > ---
> > Changes for v7:
> > - Removed the unnecessary clk_prepare/clk_unprepare calls
> > From the probe and remove as suggested by Soren.
> > Changes for v6:
> > - Updated the driver with review comments as suggested by Marc.
> > 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 | 177
> > +++++++++++++++++++++++++------------------
> > 1 file changed, 102 insertions(+), 75 deletions(-)
> >
> > diff --git a/drivers/net/can/xilinx_can.c
> > b/drivers/net/can/xilinx_can.c index fc55e8e..fcb584f 100644
> > --- a/drivers/net/can/xilinx_can.c
> > +++ b/drivers/net/can/xilinx_can.c
> > @@ -32,6 +32,7 @@
> > #include <linux/can/dev.h>
> > #include <linux/can/error.h>
> > #include <linux/can/led.h>
> > +#include <linux/pm_runtime.h>
> >
> > #define DRIVER_NAME "xilinx_can"
> >
> > @@ -138,7 +139,7 @@ struct xcan_priv {
> > u32 (*read_reg)(const struct xcan_priv *priv, enum xcan_reg reg);
> > void (*write_reg)(const struct xcan_priv *priv, enum xcan_reg reg,
> > u32 val);
> > - struct net_device *dev;
> > + struct device *dev;
> > void __iomem *reg_base;
> > unsigned long irq_flags;
> > struct clk *bus_clk;
> > @@ -843,6 +844,13 @@ static int xcan_open(struct net_device *ndev)
> > struct xcan_priv *priv = netdev_priv(ndev);
> > int ret;
> >
> > + ret = pm_runtime_get_sync(priv->dev);
> > + if (ret < 0) {
> > + netdev_err(ndev, "%s: pm_runtime_get failed(%d)\n",
> > + __func__, ret);
> > + return ret;
> > + }
> > +
> > ret = request_irq(ndev->irq, xcan_interrupt, priv->irq_flags,
> > ndev->name, ndev);
> > if (ret < 0) {
> > @@ -850,29 +858,17 @@ static int xcan_open(struct net_device *ndev)
> > goto err;
> > }
> >
> > - ret = clk_prepare_enable(priv->can_clk);
> > - if (ret) {
> > - netdev_err(ndev, "unable to enable device clock\n");
> > - goto err_irq;
> > - }
> > -
> > - ret = clk_prepare_enable(priv->bus_clk);
> > - if (ret) {
> > - netdev_err(ndev, "unable to enable bus clock\n");
> > - goto err_can_clk;
> > - }
> > -
> > /* Set chip into reset mode */
> > ret = set_reset_mode(ndev);
> > if (ret < 0) {
> > netdev_err(ndev, "mode resetting failed!\n");
> > - goto err_bus_clk;
> > + goto err_irq;
> > }
> >
> > /* Common open */
> > ret = open_candev(ndev);
> > if (ret)
> > - goto err_bus_clk;
> > + goto err_irq;
> >
> > ret = xcan_chip_start(ndev);
> > if (ret < 0) {
> > @@ -888,13 +884,11 @@ static int xcan_open(struct net_device *ndev)
> >
> > err_candev:
> > close_candev(ndev);
> > -err_bus_clk:
> > - clk_disable_unprepare(priv->bus_clk);
> > -err_can_clk:
> > - clk_disable_unprepare(priv->can_clk);
> > err_irq:
> > free_irq(ndev->irq, ndev);
> > err:
> > + pm_runtime_put(priv->dev);
> > +
> > return ret;
> > }
> >
> > @@ -911,12 +905,11 @@ static int xcan_close(struct net_device *ndev)
> > netif_stop_queue(ndev);
> > napi_disable(&priv->napi);
> > xcan_chip_stop(ndev);
> > - clk_disable_unprepare(priv->bus_clk);
> > - clk_disable_unprepare(priv->can_clk);
> > free_irq(ndev->irq, ndev);
> > close_candev(ndev);
> >
> > can_led_event(ndev, CAN_LED_EVENT_STOP);
> > + pm_runtime_put(priv->dev);
> >
> > return 0;
> > }
> > @@ -935,27 +928,20 @@ static int xcan_get_berr_counter(const struct
> net_device *ndev,
> > struct xcan_priv *priv = netdev_priv(ndev);
> > int ret;
> >
> > - ret = clk_prepare_enable(priv->can_clk);
> > - if (ret)
> > - goto err;
> > -
> > - ret = clk_prepare_enable(priv->bus_clk);
> > - if (ret)
> > - goto err_clk;
> > + ret = pm_runtime_get_sync(priv->dev);
> > + if (ret < 0) {
> > + netdev_err(ndev, "%s: pm_runtime_get failed(%d)\n",
> > + __func__, ret);
> > + return ret;
> > + }
> >
> > bec->txerr = priv->read_reg(priv, XCAN_ECR_OFFSET) &
> XCAN_ECR_TEC_MASK;
> > bec->rxerr = ((priv->read_reg(priv, XCAN_ECR_OFFSET) &
> > XCAN_ECR_REC_MASK) >> XCAN_ESR_REC_SHIFT);
> >
> > - clk_disable_unprepare(priv->bus_clk);
> > - clk_disable_unprepare(priv->can_clk);
> > + pm_runtime_put(priv->dev);
> >
> > return 0;
> > -
> > -err_clk:
> > - clk_disable_unprepare(priv->can_clk);
> > -err:
> > - return ret;
> > }
> >
> >
> > @@ -968,15 +954,45 @@ static const struct net_device_ops
> > xcan_netdev_ops = {
> >
> > /**
> > * xcan_suspend - Suspend method for the driver
> > - * @dev: Address of the platform_device structure
> > + * @dev: Address of the device structure
> > *
> > * Put the driver into low power mode.
> > - * Return: 0 always
> > + * Return: 0 on success and failure value on error
> > */
> > static int __maybe_unused xcan_suspend(struct device *dev) {
> > - struct platform_device *pdev = dev_get_drvdata(dev);
> > - struct net_device *ndev = platform_get_drvdata(pdev);
> > + if (!device_may_wakeup(dev))
> > + return pm_runtime_force_suspend(dev);
> > +
> > + return 0;
> > +}
> > +
> > +/**
> > + * xcan_resume - Resume from suspend
> > + * @dev: Address of the device structure
> > + *
> > + * Resume operation after suspend.
> > + * Return: 0 on success and failure value on error */ static int
> > +__maybe_unused xcan_resume(struct device *dev) {
> > + if (!device_may_wakeup(dev))
> > + return pm_runtime_force_resume(dev);
> > +
> > + return 0;
> > +
> > +}
> > +
> > +/**
> > + * xcan_runtime_suspend - Runtime suspend method for the driver
> > + * @dev: Address of the device structure
> > + *
> > + * Put the driver into low power mode.
> > + * Return: 0 always
> > + */
> > +static int __maybe_unused xcan_runtime_suspend(struct device *dev) {
> > + struct net_device *ndev = dev_get_drvdata(dev);
> > struct xcan_priv *priv = netdev_priv(ndev);
> >
> > if (netif_running(ndev)) {
> > @@ -987,43 +1003,55 @@ static int __maybe_unused xcan_suspend(struct
> device *dev)
> > priv->write_reg(priv, XCAN_MSR_OFFSET, XCAN_MSR_SLEEP_MASK);
> > priv->can.state = CAN_STATE_SLEEPING;
> >
> > - clk_disable(priv->bus_clk);
> > - clk_disable(priv->can_clk);
> > + clk_disable_unprepare(priv->bus_clk);
> > + clk_disable_unprepare(priv->can_clk);
> >
> > return 0;
> > }
> >
> > /**
> > - * xcan_resume - Resume from suspend
> > - * @dev: Address of the platformdevice structure
> > + * xcan_runtime_resume - Runtime resume from suspend
> > + * @dev: Address of the device structure
> > *
> > * Resume operation after suspend.
> > * Return: 0 on success and failure value on error
> > */
> > -static int __maybe_unused xcan_resume(struct device *dev)
> > +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);
> > + ret = clk_prepare_enable(priv->bus_clk);
> > if (ret) {
> > dev_err(dev, "Cannot enable clock.\n");
> > return ret;
> > }
> > - ret = clk_enable(priv->can_clk);
> > + ret = clk_prepare_enable(priv->can_clk);
> > if (ret) {
> > dev_err(dev, "Cannot enable clock.\n");
> > clk_disable_unprepare(priv->bus_clk);
> > return ret;
> > }
> >
> > - priv->write_reg(priv, XCAN_MSR_OFFSET, 0);
> > - priv->write_reg(priv, XCAN_SRR_OFFSET, XCAN_SRR_CEN_MASK);
> > - priv->can.state = CAN_STATE_ERROR_ACTIVE;
> > + priv->write_reg(priv, XCAN_SRR_OFFSET, XCAN_SRR_RESET_MASK);
> > + isr = priv->read_reg(priv, XCAN_ISR_OFFSET);
> > + status = priv->read_reg(priv, XCAN_SR_OFFSET);
> >
> > if (netif_running(ndev)) {
> > + if (isr & XCAN_IXR_BSOFF_MASK) {
> > + priv->can.state = CAN_STATE_BUS_OFF;
> > + priv->write_reg(priv, XCAN_SRR_OFFSET,
> > + XCAN_SRR_RESET_MASK);
> > + } else if ((status & XCAN_SR_ESTAT_MASK) ==
> > + XCAN_SR_ESTAT_MASK) {
> > + priv->can.state = CAN_STATE_ERROR_PASSIVE;
> > + } else if (status & XCAN_SR_ERRWRN_MASK) {
> > + priv->can.state = CAN_STATE_ERROR_WARNING;
> > + } else {
> > + priv->can.state = CAN_STATE_ERROR_ACTIVE;
> > + }
> > netif_device_attach(ndev);
> > netif_start_queue(ndev);
> > }
> > @@ -1031,7 +1059,10 @@ 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_RUNTIME_PM_OPS(xcan_runtime_suspend, xcan_runtime_resume,
> NULL)
> > +};
> >
> > /**
> > * xcan_probe - Platform registration call @@ -1072,7 +1103,7 @@
> > 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; @@ -
> 1114,21
> > +1145,18 @@ static int xcan_probe(struct platform_device *pdev)
> > }
> > }
> >
> > - ret = clk_prepare_enable(priv->can_clk);
> > - if (ret) {
> > - dev_err(&pdev->dev, "unable to enable device clock\n");
> > - goto err_free;
> > - }
> > -
> > - ret = clk_prepare_enable(priv->bus_clk);
> > - if (ret) {
> > - dev_err(&pdev->dev, "unable to enable bus clock\n");
> > - goto err_unprepare_disable_dev;
> > - }
> > -
> > priv->write_reg = xcan_write_reg_le;
> > priv->read_reg = xcan_read_reg_le;
> >
> > + pm_runtime_irq_safe(&pdev->dev);
>
> Have you tested the patch with lockdep enabled?

Yes I tested with the lockdep enabled and it is working fine.

clk_prepare_enable() can sleep
> and pm_runtime_irq_safe() says that's it's ok to call the code from atomic
> context. Either remove the pm_runtime_irq_safe() or only call the clk_enable(),
> clk_disable in the RM runtime handlers.

Ok removed the pm_runtime_irq_safe call and tested it is working fine.
Will send the next version of the path.

Regards,
Kedar.

>
> > + pm_runtime_enable(&pdev->dev);
> > + ret = pm_runtime_get_sync(&pdev->dev);
> > + if (ret < 0) {
> > + netdev_err(ndev, "%s: pm_runtime_get failed(%d)\n",
> > + __func__, ret);
> > + goto err_pmdisable;
> > + }
> > +
> > if (priv->read_reg(priv, XCAN_SR_OFFSET) != XCAN_SR_CONFIG_MASK) {
> > priv->write_reg = xcan_write_reg_be;
> > priv->read_reg = xcan_read_reg_be;
> > @@ -1141,22 +1169,23 @@ static int xcan_probe(struct platform_device
> *pdev)
> > ret = register_candev(ndev);
> > if (ret) {
> > dev_err(&pdev->dev, "fail to register failed (err=%d)\n", ret);
> > - goto err_unprepare_disable_busclk;
> > + goto err_disableclks;
> > }
> >
> > devm_can_led_init(ndev);
> > - clk_disable_unprepare(priv->bus_clk);
> > - clk_disable_unprepare(priv->can_clk);
> > +
> > + pm_runtime_put(&pdev->dev);
> > +
> > netdev_dbg(ndev, "reg_base=0x%p irq=%d clock=%d, tx fifo
> depth:%d\n",
> > priv->reg_base, ndev->irq, priv->can.clock.freq,
> > priv->tx_max);
> >
> > return 0;
> >
> > -err_unprepare_disable_busclk:
> > - clk_disable_unprepare(priv->bus_clk);
> > -err_unprepare_disable_dev:
> > - clk_disable_unprepare(priv->can_clk);
> > +err_disableclks:
> > + pm_runtime_put(priv->dev);
> > +err_pmdisable:
> > + pm_runtime_disable(&pdev->dev);
> > err_free:
> > free_candev(ndev);
> > err:
> > @@ -1175,10 +1204,8 @@ static int xcan_remove(struct platform_device
> *pdev)
> > struct net_device *ndev = platform_get_drvdata(pdev);
> > struct xcan_priv *priv = netdev_priv(ndev);
> >
> > - 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);
> > free_candev(ndev);
> >
> >
>
> 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 |

Next message: Jeffrey Merkey: "Re: linux 4.2.4 rcu_sched rolls over and barfs after debugger exits"
Previous message: Kedareswara rao Appana: "[PATCH v8] can: xilinx: Convert to runtime_pm"
In reply to: Marc Kleine-Budde: "Re: [PATCH v7] can: xilinx: Convert to runtime_pm"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]