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* [PATCH] davinci_emac: Add cpu_freq support
@ 2012-04-09 10:49 Manjunathappa, Prakash
  2012-04-09 11:29 ` Sergei Shtylyov
  2012-04-09 15:56 ` Ben Hutchings
  0 siblings, 2 replies; 3+ messages in thread
From: Manjunathappa, Prakash @ 2012-04-09 10:49 UTC (permalink / raw)
  To: netdev
  Cc: davem, linux-kernel, davinci-linux-open-source, Manjunathappa, Prakash

Reconfigure interrupt coalesce parameter for changed emac bus_freq
due to DVFS.

Signed-off-by: Manjunathappa, Prakash <prakash.pm@ti.com>
---
 drivers/net/ethernet/ti/davinci_emac.c |   60 ++++++++++++++++++++++++++++++++
 1 files changed, 60 insertions(+), 0 deletions(-)

diff --git a/drivers/net/ethernet/ti/davinci_emac.c b/drivers/net/ethernet/ti/davinci_emac.c
index 174a334..11d3bd7 100644
--- a/drivers/net/ethernet/ti/davinci_emac.c
+++ b/drivers/net/ethernet/ti/davinci_emac.c
@@ -50,6 +50,7 @@
 #include <linux/ctype.h>
 #include <linux/spinlock.h>
 #include <linux/dma-mapping.h>
+#include <linux/cpufreq.h>
 #include <linux/clk.h>
 #include <linux/platform_device.h>
 #include <linux/semaphore.h>
@@ -344,6 +345,9 @@ struct emac_priv {
 	/*platform specific members*/
 	void (*int_enable) (void);
 	void (*int_disable) (void);
+#ifdef CONFIG_CPU_FREQ
+	struct notifier_block	freq_transition;
+#endif
 };
 
 /* clock frequency for EMAC */
@@ -1761,6 +1765,46 @@ static const struct net_device_ops emac_netdev_ops = {
 #endif
 };
 
+#ifdef CONFIG_CPU_FREQ
+static int davinci_emac_cpufreq_transition(struct notifier_block *nb,
+				     unsigned long val, void *data)
+{
+	int ret = 0;
+	struct emac_priv *priv;
+
+	priv = container_of(nb, struct emac_priv, freq_transition);
+	if (priv->coal_intvl != 0) {
+		if (val == CPUFREQ_POSTCHANGE) {
+			if (emac_bus_frequency != clk_get_rate(emac_clk)) {
+				struct ethtool_coalesce coal;
+
+				emac_bus_frequency = clk_get_rate(emac_clk);
+
+				priv->bus_freq_mhz = (u32)(emac_bus_frequency /
+						1000000);
+				coal.rx_coalesce_usecs = (priv->coal_intvl
+						<< 4);
+				ret = emac_set_coalesce(priv->ndev, &coal);
+			}
+		}
+	}
+	return ret;
+}
+
+static inline int davinci_emac_cpufreq_register(struct emac_priv *priv)
+{
+	priv->freq_transition.notifier_call = davinci_emac_cpufreq_transition;
+	return cpufreq_register_notifier(&priv->freq_transition,
+					 CPUFREQ_TRANSITION_NOTIFIER);
+}
+
+static inline void davinci_emac_cpufreq_deregister(struct emac_priv *priv)
+{
+	cpufreq_unregister_notifier(&priv->freq_transition,
+				    CPUFREQ_TRANSITION_NOTIFIER);
+}
+#endif
+
 /**
  * davinci_emac_probe: EMAC device probe
  * @pdev: The DaVinci EMAC device that we are removing
@@ -1925,8 +1969,21 @@ static int __devinit davinci_emac_probe(struct platform_device *pdev)
 			   "(regs: %p, irq: %d)\n",
 			   (void *)priv->emac_base_phys, ndev->irq);
 	}
+
+#ifdef CONFIG_CPU_FREQ
+	rc = davinci_emac_cpufreq_register(priv);
+	if (rc) {
+		dev_err(&pdev->dev, "error in register_netdev\n");
+		rc = -ENODEV;
+		goto cpufreq_reg_err;
+	}
+#endif
 	return 0;
 
+#ifdef CONFIG_CPU_FREQ
+cpufreq_reg_err:
+	unregister_netdev(ndev);
+#endif
 netdev_reg_err:
 	clk_disable(emac_clk);
 no_irq_res:
@@ -1973,6 +2030,9 @@ static int __devexit davinci_emac_remove(struct platform_device *pdev)
 
 	release_mem_region(res->start, resource_size(res));
 
+#ifdef CONFIG_CPU_FREQ
+	davinci_emac_cpufreq_deregister(priv);
+#endif
 	unregister_netdev(ndev);
 	iounmap(priv->remap_addr);
 	free_netdev(ndev);
-- 
1.7.1


^ permalink raw reply related	[flat|nested] 3+ messages in thread

* Re: [PATCH] davinci_emac: Add cpu_freq support
  2012-04-09 10:49 [PATCH] davinci_emac: Add cpu_freq support Manjunathappa, Prakash
@ 2012-04-09 11:29 ` Sergei Shtylyov
  2012-04-09 15:56 ` Ben Hutchings
  1 sibling, 0 replies; 3+ messages in thread
From: Sergei Shtylyov @ 2012-04-09 11:29 UTC (permalink / raw)
  To: Manjunathappa, Prakash
  Cc: netdev, davinci-linux-open-source, davem, linux-kernel

Hello.

On 09-04-2012 14:49, Manjunathappa, Prakash wrote:

> Reconfigure interrupt coalesce parameter for changed emac bus_freq
> due to DVFS.

> Signed-off-by: Manjunathappa, Prakash<prakash.pm@ti.com>
> ---
>   drivers/net/ethernet/ti/davinci_emac.c |   60 ++++++++++++++++++++++++++++++++
>   1 files changed, 60 insertions(+), 0 deletions(-)

> diff --git a/drivers/net/ethernet/ti/davinci_emac.c b/drivers/net/ethernet/ti/davinci_emac.c
> index 174a334..11d3bd7 100644
> --- a/drivers/net/ethernet/ti/davinci_emac.c
> +++ b/drivers/net/ethernet/ti/davinci_emac.c
[...]
> @@ -1761,6 +1765,46 @@ static const struct net_device_ops emac_netdev_ops = {
>   #endif
>   };
>
> +#ifdef CONFIG_CPU_FREQ
> +static int davinci_emac_cpufreq_transition(struct notifier_block *nb,
> +				     unsigned long val, void *data)
> +{
> +	int ret = 0;
> +	struct emac_priv *priv;
> +
> +	priv = container_of(nb, struct emac_priv, freq_transition);
> +	if (priv->coal_intvl != 0) {
> +		if (val == CPUFREQ_POSTCHANGE) {
> +			if (emac_bus_frequency != clk_get_rate(emac_clk)) {

    These 3 *if*s could be collapsed into one, and so indentation level 
lowered significantly.

> +				struct ethtool_coalesce coal;
> +
> +				emac_bus_frequency = clk_get_rate(emac_clk);
> +
> +				priv->bus_freq_mhz = (u32)(emac_bus_frequency /
> +						1000000);
> +				coal.rx_coalesce_usecs = (priv->coal_intvl
> +						<<  4);
> +				ret = emac_set_coalesce(priv->ndev,&coal);
> +			}
> +		}
> +	}
> +	return ret;
> +}
> +
> +static inline int davinci_emac_cpufreq_register(struct emac_priv *priv)
> +{
> +	priv->freq_transition.notifier_call = davinci_emac_cpufreq_transition;
> +	return cpufreq_register_notifier(&priv->freq_transition,
> +					 CPUFREQ_TRANSITION_NOTIFIER);
> +}
> +
> +static inline void davinci_emac_cpufreq_deregister(struct emac_priv *priv)
> +{
> +	cpufreq_unregister_notifier(&priv->freq_transition,
> +				    CPUFREQ_TRANSITION_NOTIFIER);
> +}
> +#endif
> +
>   /**
>    * davinci_emac_probe: EMAC device probe
>    * @pdev: The DaVinci EMAC device that we are removing
> @@ -1925,8 +1969,21 @@ static int __devinit davinci_emac_probe(struct platform_device *pdev)
>   			   "(regs: %p, irq: %d)\n",
>   			   (void *)priv->emac_base_phys, ndev->irq);
>   	}
> +
> +#ifdef CONFIG_CPU_FREQ
> +	rc = davinci_emac_cpufreq_register(priv);
> +	if (rc) {
> +		dev_err(&pdev->dev, "error in register_netdev\n");

    Really?

> +		rc = -ENODEV;
> +		goto cpufreq_reg_err;
> +	}
> +#endif
>   	return 0;
>
> +#ifdef CONFIG_CPU_FREQ
> +cpufreq_reg_err:
> +	unregister_netdev(ndev);
> +#endif
>   netdev_reg_err:
>   	clk_disable(emac_clk);
>   no_irq_res:
> @@ -1973,6 +2030,9 @@ static int __devexit davinci_emac_remove(struct platform_device *pdev)
>
>   	release_mem_region(res->start, resource_size(res));
>
> +#ifdef CONFIG_CPU_FREQ
> +	davinci_emac_cpufreq_deregister(priv);
> +#endif

    This is considered a bad practice to use #ifdef in the body of function.
Define the faunction you call here as empty inline in case CONFIG_CPU_FREQ is 
not defined instead. The same about davinci_emac_cpufreq_register().

WBR, Sergei

^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: [PATCH] davinci_emac: Add cpu_freq support
  2012-04-09 10:49 [PATCH] davinci_emac: Add cpu_freq support Manjunathappa, Prakash
  2012-04-09 11:29 ` Sergei Shtylyov
@ 2012-04-09 15:56 ` Ben Hutchings
  1 sibling, 0 replies; 3+ messages in thread
From: Ben Hutchings @ 2012-04-09 15:56 UTC (permalink / raw)
  To: Manjunathappa, Prakash
  Cc: netdev, davem, linux-kernel, davinci-linux-open-source

On Mon, 2012-04-09 at 16:19 +0530, Manjunathappa, Prakash wrote:
> Reconfigure interrupt coalesce parameter for changed emac bus_freq
> due to DVFS.
> 
> Signed-off-by: Manjunathappa, Prakash <prakash.pm@ti.com>
> ---
>  drivers/net/ethernet/ti/davinci_emac.c |   60 ++++++++++++++++++++++++++++++++
>  1 files changed, 60 insertions(+), 0 deletions(-)
> 
> diff --git a/drivers/net/ethernet/ti/davinci_emac.c b/drivers/net/ethernet/ti/davinci_emac.c
> index 174a334..11d3bd7 100644
> --- a/drivers/net/ethernet/ti/davinci_emac.c
> +++ b/drivers/net/ethernet/ti/davinci_emac.c
> @@ -50,6 +50,7 @@
>  #include <linux/ctype.h>
>  #include <linux/spinlock.h>
>  #include <linux/dma-mapping.h>
> +#include <linux/cpufreq.h>
>  #include <linux/clk.h>
>  #include <linux/platform_device.h>
>  #include <linux/semaphore.h>
> @@ -344,6 +345,9 @@ struct emac_priv {
>  	/*platform specific members*/
>  	void (*int_enable) (void);
>  	void (*int_disable) (void);
> +#ifdef CONFIG_CPU_FREQ
> +	struct notifier_block	freq_transition;
> +#endif
>  };
>  
>  /* clock frequency for EMAC */
> @@ -1761,6 +1765,46 @@ static const struct net_device_ops emac_netdev_ops = {
>  #endif
>  };
>  
> +#ifdef CONFIG_CPU_FREQ
> +static int davinci_emac_cpufreq_transition(struct notifier_block *nb,
> +				     unsigned long val, void *data)
> +{
> +	int ret = 0;
> +	struct emac_priv *priv;
> +
> +	priv = container_of(nb, struct emac_priv, freq_transition);
> +	if (priv->coal_intvl != 0) {
> +		if (val == CPUFREQ_POSTCHANGE) {
> +			if (emac_bus_frequency != clk_get_rate(emac_clk)) {
> +				struct ethtool_coalesce coal;
> +
> +				emac_bus_frequency = clk_get_rate(emac_clk);
> +
> +				priv->bus_freq_mhz = (u32)(emac_bus_frequency /
> +						1000000);
> +				coal.rx_coalesce_usecs = (priv->coal_intvl
> +						<< 4);
> +				ret = emac_set_coalesce(priv->ndev, &coal);
[...]

Ick.  Why don't you break up emac_set_coalesce() so that you can push
this one value to the hardware without faking up a struct
ethtool_coalesce?  Don't you need to push it on reset/resume anyway?

Ben.

-- 
Ben Hutchings, Staff Engineer, Solarflare
Not speaking for my employer; that's the marketing department's job.
They asked us to note that Solarflare product names are trademarked.


^ permalink raw reply	[flat|nested] 3+ messages in thread

end of thread, other threads:[~2012-04-09 15:56 UTC | newest]

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2012-04-09 10:49 [PATCH] davinci_emac: Add cpu_freq support Manjunathappa, Prakash
2012-04-09 11:29 ` Sergei Shtylyov
2012-04-09 15:56 ` Ben Hutchings

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