Re: [PATCH v5] can: c_can: Add runtime PM support to Bosch C_CAN/D_CAN controller
From: Marc Kleine-Budde <mkl@pengutronix.de>
Date: 2012-08-07 11:57:05
Also in:
linux-omap
On 08/07/2012 01:20 PM, AnilKumar Ch wrote:
Add Runtime PM support to C_CAN/D_CAN controller. The runtime PM APIs control clocks for C_CAN/D_CAN IP and prevent access to the register of C_CAN/D_CAN IP when clock is turned off. Signed-off-by: AnilKumar Ch <redacted> --- This patch has been tested on AM335X EVM. Due to lack of hardware I am not able to test c_can functionality. I appreciate if anyone can test c_can functionality with this patch.
The "priv->pdev->dev" will not work for c_can/d_can which are not using
the platform driver. Options:
a) priv->dev
add a struct device pointer to the priv, and
1) guard pm_runtime_get_sync() for priv->dev == NULL
(or check if pm_runtime_get_sync copes with NULL pointer)
- or -
2) fill in the priv->dev in all other drivers (i.e. PCI)
and check if it makes sense/works to call it on PCI hardware
b) convert all other drivers, i.e. the PCI driver to create a
platform device
Without thinking long, I suggest to a) with flavour 1)
Maybe there are better solutions.
Marc
More comments inline:
quoted hunk ↗ jump to hunk
This patch is based on "can-next/master" Changes from v4: - Incorporated Vaibhav H review comments on v4. * Moved pm_runtime put/get_sync calls to appropriate positions. - This patch is from "Add DT support to C_CAN/D_CAN controller" patch series. Rest of the patches in this series were applied so this v5 contains only this patch. drivers/net/can/c_can/c_can.c | 8 ++++++++ drivers/net/can/c_can/c_can.h | 1 + drivers/net/can/c_can/c_can_platform.c | 11 +++++++++++ 3 files changed, 20 insertions(+)diff --git a/drivers/net/can/c_can/c_can.c b/drivers/net/can/c_can/c_can.c index eea6608..ca1151d 100644 --- a/drivers/net/can/c_can/c_can.c +++ b/drivers/net/can/c_can/c_can.c@@ -34,6 +34,8 @@ #include <linux/if_ether.h> #include <linux/list.h> #include <linux/io.h> +#include <linux/pm_runtime.h> +#include <linux/platform_device.h> #include <linux/can.h> #include <linux/can/dev.h>@@ -673,6 +675,8 @@ static int c_can_get_berr_counter(const struct net_device *dev, unsigned int reg_err_counter; struct c_can_priv *priv = netdev_priv(dev); + pm_runtime_get_sync(&priv->pdev->dev); +
Why do you make a get_sync() here, where's the correspondning put_sync()?
quoted hunk ↗ jump to hunk
reg_err_counter = priv->read_reg(priv, C_CAN_ERR_CNT_REG); bec->rxerr = (reg_err_counter & ERR_CNT_REC_MASK) >> ERR_CNT_REC_SHIFT;@@ -1053,6 +1057,8 @@ static int c_can_open(struct net_device *dev) int err; struct c_can_priv *priv = netdev_priv(dev); + pm_runtime_get_sync(&priv->pdev->dev); + /* open the can device */ err = open_candev(dev); if (err) {
What if open_candev() fails? Please add a jump label exit_open_candev_fail and add thje put_sync() there. goto exit_open_candev_fail;
quoted hunk ↗ jump to hunk
@@ -1079,6 +1085,7 @@ static int c_can_open(struct net_device *dev) exit_irq_fail: close_candev(dev);
exit_open_candev_fail:
quoted hunk ↗ jump to hunk
+ pm_runtime_put_sync(&priv->pdev->dev); return err; }@@ -1091,6 +1098,7 @@ static int c_can_close(struct net_device *dev) c_can_stop(dev); free_irq(dev->irq, dev); close_candev(dev); + pm_runtime_put_sync(&priv->pdev->dev); return 0; }diff --git a/drivers/net/can/c_can/c_can.h b/drivers/net/can/c_can/c_can.h index 4e56baa..ef84439 100644 --- a/drivers/net/can/c_can/c_can.h +++ b/drivers/net/can/c_can/c_can.h@@ -153,6 +153,7 @@ struct c_can_priv { struct can_priv can; /* must be the first member */ struct napi_struct napi; struct net_device *dev; + struct platform_device *pdev; int tx_object; int current_status; int last_status;diff --git a/drivers/net/can/c_can/c_can_platform.c b/drivers/net/can/c_can/c_can_platform.c index d0a66cf..cbb1184 100644 --- a/drivers/net/can/c_can/c_can_platform.c +++ b/drivers/net/can/c_can/c_can_platform.c@@ -32,6 +32,7 @@ #include <linux/clk.h> #include <linux/of.h> #include <linux/of_device.h> +#include <linux/pm_runtime.h> #include <linux/can/dev.h>@@ -177,7 +178,11 @@ static int __devinit c_can_plat_probe(struct platform_device *pdev) goto exit_free_device; } + pm_runtime_enable(&pdev->dev); + pm_runtime_get_sync(&pdev->dev); + dev->irq = irq; + priv->pdev = pdev; priv->base = addr; priv->can.clock.freq = clk_get_rate(clk); priv->priv = clk;@@ -192,12 +197,16 @@ static int __devinit c_can_plat_probe(struct platform_device *pdev) goto exit_free_device; } + pm_runtime_put_sync(&pdev->dev); + dev_info(&pdev->dev, "%s device registered (regs=%p, irq=%d)\n", KBUILD_MODNAME, priv->base, dev->irq); return 0; exit_free_device: platform_set_drvdata(pdev, NULL); + pm_runtime_put_sync(&pdev->dev); + pm_runtime_disable(&pdev->dev); free_c_can_dev(dev); exit_iounmap: iounmap(addr);@@ -226,6 +235,8 @@ static int __devexit c_can_plat_remove(struct platform_device *pdev) mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); release_mem_region(mem->start, resource_size(mem)); + pm_runtime_put_sync(&pdev->dev); + pm_runtime_disable(&pdev->dev); clk_put(priv->priv); return 0;
-- 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 |
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