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[PATCH] davinci_emac: Add cpu_freq support

 

 

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prakash.pm at ti

Apr 9, 2012, 3:49 AM

Post #1 of 3 (70 views)
Permalink
[PATCH] davinci_emac: Add cpu_freq support

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

Signed-off-by: Manjunathappa, Prakash <prakash.pm [at] ti>
---
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

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sshtylyov at mvista

Apr 9, 2012, 4:29 AM

Post #2 of 3 (65 views)
Permalink
Re: [PATCH] davinci_emac: Add cpu_freq support [In reply to]

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 [at] ti>
> ---
> 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
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bhutchings at solarflare

Apr 9, 2012, 8:56 AM

Post #3 of 3 (62 views)
Permalink
Re: [PATCH] davinci_emac: Add cpu_freq support [In reply to]

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 [at] ti>
> ---
> 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.

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