Re: [PATCH v6] can: xilinx: Convert to runtime_pm

From: SÃren Brinkmann
Date: Thu Oct 22 2015 - 18:13:47 EST


Hi Kedar,

On Thu, 2015-10-22 at 10:15AM +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: Kedareswara rao Appana <appanad@xxxxxxxxxx>
[...]
> /**
> * 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 +1145,30 @@ static int xcan_probe(struct platform_device *pdev)
> }
> }
>
> - ret = clk_prepare_enable(priv->can_clk);
> + ret = clk_prepare(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);
> + ret = clk_prepare(priv->bus_clk);

Are these clk_prepare calls needed here? The runtime PM calls do
clk_prepare_enable and clk_disable_unprepare.

> if (ret) {
> dev_err(&pdev->dev, "unable to enable bus clock\n");
> - goto err_unprepare_disable_dev;
> + goto err_unprepare_dev;
> }
>
> priv->write_reg = xcan_write_reg_le;
> priv->read_reg = xcan_read_reg_le;
>
> + pm_runtime_irq_safe(&pdev->dev);
> + 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_unprepare_busclk;
> + }
> +
> 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 +1181,26 @@ 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_unprepare_busclk:
> + pm_runtime_disable(&pdev->dev);
> + clk_unprepare(priv->bus_clk);
> +err_unprepare_dev:
> + clk_unprepare(priv->can_clk);
> err_free:
> free_candev(ndev);
> err:
> @@ -1175,11 +1219,11 @@ 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);
> + clk_unprepare(priv->bus_clk);
> + clk_unprepare(priv->can_clk);

I think this can go away when the prepare calls in probe go away.

Thanks,
SÃren
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