RE: [PATCH v4] can: Convert to runtime_pm
From: Appana Durga Kedareswara Rao
Date: Tue Dec 23 2014 - 07:27:28 EST
Hi Marc,
I tried by splitting the xcan_berr_counter to __xcan_berr_counter but still seeing
the same crash as pointed by the Soren in the previous version of the patch.
Updated the driver with the other review comments in this patch.
Regards,
Kedar.
-----Original Message-----
From: Kedareswara rao Appana [mailto:appana.durga.rao@xxxxxxxxxx]
Sent: Tuesday, December 23, 2014 5:55 PM
To: wg@xxxxxxxxxxxxxx; mkl@xxxxxxxxxxxxxx; Michal Simek; grant.likely@xxxxxxxxxx
Cc: linux-can@xxxxxxxxxxxxxxx; netdev@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; Appana Durga Kedareswara Rao; Soren Brinkmann
Subject: [PATCH v4] can: Convert to runtime_pm
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>
---
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 | 123 +++++++++++++++++++++++++-----------------
1 files changed, 74 insertions(+), 49 deletions(-)
diff --git a/drivers/net/can/xilinx_can.c b/drivers/net/can/xilinx_can.c index 6c67643..c71f683 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;
@@ -842,6 +843,13 @@ 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\r(%d)\n\r",
+ __func__, ret);
+ return ret;
+ }
+
ret = request_irq(ndev->irq, xcan_interrupt, priv->irq_flags,
ndev->name, ndev);
if (ret < 0) {
@@ -849,29 +857,17 @@ 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) {
@@ -887,13 +883,11 @@ 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;
}
@@ -910,12 +904,11 @@ 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;
}
@@ -934,27 +927,20 @@ 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\r(%d)\n\r",
+ __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;
}
@@ -967,15 +953,45 @@ 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)) {
@@ -993,16 +1009,15 @@ static int __maybe_unused xcan_suspend(struct device *dev) }
/**
- * 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;
@@ -1020,9 +1035,9 @@ static int __maybe_unused xcan_resume(struct device *dev)
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;
if (netif_running(ndev)) {
+ priv->can.state = CAN_STATE_ERROR_ACTIVE;
netif_device_attach(ndev);
netif_start_queue(ndev);
}
@@ -1030,7 +1045,10 @@ 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_PM_RUNTIME_PM_OPS(xcan_runtime_suspend, xcan_runtime_resume, NULL)
+};
/**
* xcan_probe - Platform registration call @@ -1071,7 +1089,7 @@ 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; @@ -1137,15 +1155,22 @@ static int xcan_probe(struct platform_device *pdev)
netif_napi_add(ndev, &priv->napi, xcan_rx_poll, rx_max);
+ pm_runtime_set_active(&pdev->dev);
+ pm_runtime_irq_safe(&pdev->dev);
+ pm_runtime_enable(&pdev->dev);
+ pm_runtime_get_sync(&pdev->dev);
+
ret = register_candev(ndev);
if (ret) {
dev_err(&pdev->dev, "fail to register failed (err=%d)\n", ret);
+ pm_runtime_put(priv->dev);
goto err_unprepare_disable_busclk;
}
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);
--
1.7.4
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