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

Hi Soren,

-----Original Message-----
From: Sören Brinkmann [mailto:soren.brinkmann@xilinx.com]
Sent: Friday, October 23, 2015 3:43 AM
To: Appana Durga Kedareswara Rao
Cc: Anirudha Sarangi; wg@grandegger.com; mkl@pengutronix.de; Michal
Simek; linux-can@vger.kernel.org; netdev@vger.kernel.org; linux-arm-
kernel@lists.infradead.org; linux-kernel@vger.kernel.org; Appana Durga
Kedareswara Rao
Subject: Re: [PATCH v6] can: xilinx: Convert to runtime_pm

Hi Kedar,

On Thu, 2015-10-22 at 10:15AM +0530, Kedareswara rao Appana wrote:

quoted

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.

quoted

Signed-off-by: Kedareswara rao Appana <redacted>

[...]

quoted

 /**
  * 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

quoted

+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.

Ok Sure will remove.

quoted

 	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)

quoted

 	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",

quoted

 			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)

quoted

 	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.

Ok will fix and will send next version of the patch.

Regards,
Kedar.

	Thanks,
	Sören