[net-next,v2,5/5] net: ravb: Add runtime PM support

Commit Message

Claudiu Beznea Feb. 9, 2024, 5:04 p.m. UTC

From: Claudiu Beznea <[e-mail]>

Add runtime PM support for the ravb driver. As the driver is used by
different IP variants, with different behaviors, to be able to have the
runtime PM support available for all devices, the preparatory commits
moved all the resources parsing and allocations in the driver's probe
function and kept the settings for ravb_open(). This is due to the fact
that on some IP variants-platforms tuples disabling/enabling the clocks
will switch the IP to the reset operation mode where registers' content is
lost and reconfiguration needs to be done. For this the rabv_open()
function enables the clocks, switches the IP to configuration mode, applies
all the registers settings and switches the IP to the operational mode. At
the end of ravb_open() IP is ready to send/receive data.

In ravb_close() necessary reverts are done (compared with ravb_open()), the
IP is switched to reset mode and clocks are disabled.

The ethtool APIs or IOCTLs that might execute while the interface is down
are either cached (and applied in ravb_open()) or rejected (as at that time
the IP is in reset mode). Keeping the IP in the reset mode also increases
the power saved (according to the hardware manual).

Signed-off-by: Claudiu Beznea <[e-mail]>
Reviewed-by: Sergey Shtylyov <[e-mail]>
---

Changes in v2:
- none

Changes since [2]:
- none
- didn't returned directly the ret code of pm_runtime_put_autosuspend()
  as, in theory, it might return 1 in case device is suspended through
  this calltrace:
  pm_runtime_put_autosuspend() ->
    __pm_runtime_suspend() ->
      rpm_suspend() ->
        rpm_check_suspend_allowed()

Changes in v3 of [2]:
- this was patch 21/21 in v2
- collected tags
- fixed typos in patch description

Changes in v2 of [2]:
- keep RPM support for all platforms

[2] https://lore.kernel.org/all/[e-mail]/

 drivers/net/ethernet/renesas/ravb_main.c | 54 ++++++++++++++++++++++--
 1 file changed, 50 insertions(+), 4 deletions(-)

Comments

Sergey Shtylyov Feb. 9, 2024, 9 p.m. UTC | #1

On 2/9/24 8:04 PM, Claudiu wrote:

> From: Claudiu Beznea <[e-mail]>
> 
> Add runtime PM support for the ravb driver. As the driver is used by
> different IP variants, with different behaviors, to be able to have the
> runtime PM support available for all devices, the preparatory commits
> moved all the resources parsing and allocations in the driver's probe
> function and kept the settings for ravb_open(). This is due to the fact
> that on some IP variants-platforms tuples disabling/enabling the clocks
> will switch the IP to the reset operation mode where registers' content is

   This pesky "registers' content" somehow evaded me -- should be "register
contents" as well...

> lost and reconfiguration needs to be done. For this the rabv_open()
> function enables the clocks, switches the IP to configuration mode, applies
> all the registers settings and switches the IP to the operational mode. At
> the end of ravb_open() IP is ready to send/receive data.
> 
> In ravb_close() necessary reverts are done (compared with ravb_open()), the
> IP is switched to reset mode and clocks are disabled.
> 
> The ethtool APIs or IOCTLs that might execute while the interface is down
> are either cached (and applied in ravb_open()) or rejected (as at that time
> the IP is in reset mode). Keeping the IP in the reset mode also increases
> the power saved (according to the hardware manual).
> 
> Signed-off-by: Claudiu Beznea <[e-mail]>
> Reviewed-by: Sergey Shtylyov <[e-mail]>
[...]

> diff --git a/drivers/net/ethernet/renesas/ravb_main.c b/drivers/net/ethernet/renesas/ravb_main.c
> index f4be08f0198d..5bbfdfeef8a9 100644
> --- a/drivers/net/ethernet/renesas/ravb_main.c
> +++ b/drivers/net/ethernet/renesas/ravb_main.c
> @@ -1939,16 +1939,21 @@ static int ravb_open(struct net_device *ndev)
>  {
>  	struct ravb_private *priv = netdev_priv(ndev);
>  	const struct ravb_hw_info *info = priv->info;
> +	struct device *dev = &priv->pdev->dev;
>  	int error;
>  
>  	napi_enable(&priv->napi[RAVB_BE]);
>  	if (info->nc_queues)
>  		napi_enable(&priv->napi[RAVB_NC]);
>  
> +	error = pm_runtime_resume_and_get(dev);
> +	if (error < 0)
> +		goto out_napi_off;

   Well, s/error/ret/ -- it would fit better here...

[...]
> @@ -3066,6 +3089,12 @@ static void ravb_remove(struct platform_device *pdev)
>  	struct net_device *ndev = platform_get_drvdata(pdev);
>  	struct ravb_private *priv = netdev_priv(ndev);
>  	const struct ravb_hw_info *info = priv->info;
> +	struct device *dev = &priv->pdev->dev;
> +	int error;
> +
> +	error = pm_runtime_resume_and_get(dev);
> +	if (error < 0)
> +		return;

   Again, s/erorr/ret/ in this case.

[...]

MBR, Sergey

Claudiu Beznea Feb. 12, 2024, 7:56 a.m. UTC | #2

On 09.02.2024 23:00, Sergey Shtylyov wrote:
> On 2/9/24 8:04 PM, Claudiu wrote:
> 
>> From: Claudiu Beznea <[e-mail]>
>>
>> Add runtime PM support for the ravb driver. As the driver is used by
>> different IP variants, with different behaviors, to be able to have the
>> runtime PM support available for all devices, the preparatory commits
>> moved all the resources parsing and allocations in the driver's probe
>> function and kept the settings for ravb_open(). This is due to the fact
>> that on some IP variants-platforms tuples disabling/enabling the clocks
>> will switch the IP to the reset operation mode where registers' content is
> 
>    This pesky "registers' content" somehow evaded me -- should be "register
> contents" as well...
> 
>> lost and reconfiguration needs to be done. For this the rabv_open()
>> function enables the clocks, switches the IP to configuration mode, applies
>> all the registers settings and switches the IP to the operational mode. At
>> the end of ravb_open() IP is ready to send/receive data.
>>
>> In ravb_close() necessary reverts are done (compared with ravb_open()), the
>> IP is switched to reset mode and clocks are disabled.
>>
>> The ethtool APIs or IOCTLs that might execute while the interface is down
>> are either cached (and applied in ravb_open()) or rejected (as at that time
>> the IP is in reset mode). Keeping the IP in the reset mode also increases
>> the power saved (according to the hardware manual).
>>
>> Signed-off-by: Claudiu Beznea <[e-mail]>
>> Reviewed-by: Sergey Shtylyov <[e-mail]>
> [...]
> 
>> diff --git a/drivers/net/ethernet/renesas/ravb_main.c b/drivers/net/ethernet/renesas/ravb_main.c
>> index f4be08f0198d..5bbfdfeef8a9 100644
>> --- a/drivers/net/ethernet/renesas/ravb_main.c
>> +++ b/drivers/net/ethernet/renesas/ravb_main.c
>> @@ -1939,16 +1939,21 @@ static int ravb_open(struct net_device *ndev)
>>  {
>>  	struct ravb_private *priv = netdev_priv(ndev);
>>  	const struct ravb_hw_info *info = priv->info;
>> +	struct device *dev = &priv->pdev->dev;
>>  	int error;
>>  
>>  	napi_enable(&priv->napi[RAVB_BE]);
>>  	if (info->nc_queues)
>>  		napi_enable(&priv->napi[RAVB_NC]);
>>  
>> +	error = pm_runtime_resume_and_get(dev);
>> +	if (error < 0)
>> +		goto out_napi_off;
> 
>    Well, s/error/ret/ -- it would fit better here...

Using error is the "trademark" of this driver, it is used all around the
driver. I haven't introduced it here, I don't like it. The variable error
in this particular function is here from the beginning of the driver.

So, I don't consider changing error to ret is the scope of this series.

> 
> [...]
>> @@ -3066,6 +3089,12 @@ static void ravb_remove(struct platform_device *pdev)
>>  	struct net_device *ndev = platform_get_drvdata(pdev);
>>  	struct ravb_private *priv = netdev_priv(ndev);
>>  	const struct ravb_hw_info *info = priv->info;
>> +	struct device *dev = &priv->pdev->dev;
>> +	int error;
>> +
>> +	error = pm_runtime_resume_and_get(dev);
>> +	if (error < 0)
>> +		return;
> 
>    Again, s/erorr/ret/ in this case.

error was used here to comply with the rest of the driver. So, if you still
want me to change it here and in ravb_remove() please confirm.

Thank you,
Claudiu Beznea

> 
> [...]
> 
> MBR, Sergey

Sergey Shtylyov Feb. 12, 2024, 8:19 p.m. UTC | #3

On 2/12/24 10:56 AM, claudiu beznea wrote:

[...]

>>> From: Claudiu Beznea <[e-mail]>
>>>
>>> Add runtime PM support for the ravb driver. As the driver is used by
>>> different IP variants, with different behaviors, to be able to have the
>>> runtime PM support available for all devices, the preparatory commits
>>> moved all the resources parsing and allocations in the driver's probe
>>> function and kept the settings for ravb_open(). This is due to the fact
>>> that on some IP variants-platforms tuples disabling/enabling the clocks
>>> will switch the IP to the reset operation mode where registers' content is
>>
>>    This pesky "registers' content" somehow evaded me -- should be "register
>> contents" as well...
>>
>>> lost and reconfiguration needs to be done. For this the rabv_open()
>>> function enables the clocks, switches the IP to configuration mode, applies
>>> all the registers settings and switches the IP to the operational mode. At
>>> the end of ravb_open() IP is ready to send/receive data.
>>>
>>> In ravb_close() necessary reverts are done (compared with ravb_open()), the
>>> IP is switched to reset mode and clocks are disabled.
>>>
>>> The ethtool APIs or IOCTLs that might execute while the interface is down
>>> are either cached (and applied in ravb_open()) or rejected (as at that time
>>> the IP is in reset mode). Keeping the IP in the reset mode also increases
>>> the power saved (according to the hardware manual).
>>>
>>> Signed-off-by: Claudiu Beznea <[e-mail]>
>>> Reviewed-by: Sergey Shtylyov <[e-mail]>
>> [...]
>>
>>> diff --git a/drivers/net/ethernet/renesas/ravb_main.c b/drivers/net/ethernet/renesas/ravb_main.c
>>> index f4be08f0198d..5bbfdfeef8a9 100644
>>> --- a/drivers/net/ethernet/renesas/ravb_main.c
>>> +++ b/drivers/net/ethernet/renesas/ravb_main.c
>>> @@ -1939,16 +1939,21 @@ static int ravb_open(struct net_device *ndev)
>>>  {
>>>  	struct ravb_private *priv = netdev_priv(ndev);
>>>  	const struct ravb_hw_info *info = priv->info;
>>> +	struct device *dev = &priv->pdev->dev;
>>>  	int error;
>>>  
>>>  	napi_enable(&priv->napi[RAVB_BE]);
>>>  	if (info->nc_queues)
>>>  		napi_enable(&priv->napi[RAVB_NC]);
>>>  
>>> +	error = pm_runtime_resume_and_get(dev);
>>> +	if (error < 0)
>>> +		goto out_napi_off;
>>
>>    Well, s/error/ret/ -- it would fit better here...
> 
> Using error is the "trademark" of this driver, it is used all around the
> driver. I haven't introduced it here, I don't like it. The variable error

   Heh, because it's my usual style. Too bad you don't like it... :-)

> in this particular function is here from the beginning of the driver.

   I think it's well suited for the functions returning either 0 or a
(negative) error code. It's *if* (error < 0) that confuses me (as this
API can return positive numbers in case of success...

> So, I don't consider changing error to ret is the scope of this series.

   OK, you're probably right... are you going to respin the series because
of Biju's comments?

[...]
>>> @@ -3066,6 +3089,12 @@ static void ravb_remove(struct platform_device *pdev)
>>>  	struct net_device *ndev = platform_get_drvdata(pdev);
>>>  	struct ravb_private *priv = netdev_priv(ndev);
>>>  	const struct ravb_hw_info *info = priv->info;
>>> +	struct device *dev = &priv->pdev->dev;
>>> +	int error;
>>> +
>>> +	error = pm_runtime_resume_and_get(dev);
>>> +	if (error < 0)
>>> +		return;
>>
>>    Again, s/erorr/ret/ in this case.
> 
> error was used here to comply with the rest of the driver. So, if you still
> want me to change it here and in ravb_remove() please confirm.

   No, we are good enough without that; I'll consider doing a cleanup
when/if I have time. :-)

> Thank you,
> Claudiu Beznea

MBR, Sergey

Claudiu Beznea Feb. 13, 2024, 6:59 a.m. UTC | #4

On 12.02.2024 22:19, Sergey Shtylyov wrote:
> On 2/12/24 10:56 AM, claudiu beznea wrote:
> 
> [...]
> 
>>>> From: Claudiu Beznea <[e-mail]>
>>>>
>>>> Add runtime PM support for the ravb driver. As the driver is used by
>>>> different IP variants, with different behaviors, to be able to have the
>>>> runtime PM support available for all devices, the preparatory commits
>>>> moved all the resources parsing and allocations in the driver's probe
>>>> function and kept the settings for ravb_open(). This is due to the fact
>>>> that on some IP variants-platforms tuples disabling/enabling the clocks
>>>> will switch the IP to the reset operation mode where registers' content is
>>>
>>>    This pesky "registers' content" somehow evaded me -- should be "register
>>> contents" as well...
>>>
>>>> lost and reconfiguration needs to be done. For this the rabv_open()
>>>> function enables the clocks, switches the IP to configuration mode, applies
>>>> all the registers settings and switches the IP to the operational mode. At
>>>> the end of ravb_open() IP is ready to send/receive data.
>>>>
>>>> In ravb_close() necessary reverts are done (compared with ravb_open()), the
>>>> IP is switched to reset mode and clocks are disabled.
>>>>
>>>> The ethtool APIs or IOCTLs that might execute while the interface is down
>>>> are either cached (and applied in ravb_open()) or rejected (as at that time
>>>> the IP is in reset mode). Keeping the IP in the reset mode also increases
>>>> the power saved (according to the hardware manual).
>>>>
>>>> Signed-off-by: Claudiu Beznea <[e-mail]>
>>>> Reviewed-by: Sergey Shtylyov <[e-mail]>
>>> [...]
>>>
>>>> diff --git a/drivers/net/ethernet/renesas/ravb_main.c b/drivers/net/ethernet/renesas/ravb_main.c
>>>> index f4be08f0198d..5bbfdfeef8a9 100644
>>>> --- a/drivers/net/ethernet/renesas/ravb_main.c
>>>> +++ b/drivers/net/ethernet/renesas/ravb_main.c
>>>> @@ -1939,16 +1939,21 @@ static int ravb_open(struct net_device *ndev)
>>>>  {
>>>>  	struct ravb_private *priv = netdev_priv(ndev);
>>>>  	const struct ravb_hw_info *info = priv->info;
>>>> +	struct device *dev = &priv->pdev->dev;
>>>>  	int error;
>>>>  
>>>>  	napi_enable(&priv->napi[RAVB_BE]);
>>>>  	if (info->nc_queues)
>>>>  		napi_enable(&priv->napi[RAVB_NC]);
>>>>  
>>>> +	error = pm_runtime_resume_and_get(dev);
>>>> +	if (error < 0)
>>>> +		goto out_napi_off;
>>>
>>>    Well, s/error/ret/ -- it would fit better here...
>>
>> Using error is the "trademark" of this driver, it is used all around the
>> driver. I haven't introduced it here, I don't like it. The variable error
> 
>    Heh, because it's my usual style. Too bad you don't like it... :-)
> 
>> in this particular function is here from the beginning of the driver.
> 
>    I think it's well suited for the functions returning either 0 or a
> (negative) error code. It's *if* (error < 0) that confuses me (as this
> API can return positive numbers in case of success...
> 
>> So, I don't consider changing error to ret is the scope of this series.
> 
>    OK, you're probably right... are you going to respin the series because
> of Biju's comments?

Yes!

Thank you,
Claudiu Beznea

> 
> [...]
>>>> @@ -3066,6 +3089,12 @@ static void ravb_remove(struct platform_device *pdev)
>>>>  	struct net_device *ndev = platform_get_drvdata(pdev);
>>>>  	struct ravb_private *priv = netdev_priv(ndev);
>>>>  	const struct ravb_hw_info *info = priv->info;
>>>> +	struct device *dev = &priv->pdev->dev;
>>>> +	int error;
>>>> +
>>>> +	error = pm_runtime_resume_and_get(dev);
>>>> +	if (error < 0)
>>>> +		return;
>>>
>>>    Again, s/erorr/ret/ in this case.
>>
>> error was used here to comply with the rest of the driver. So, if you still
>> want me to change it here and in ravb_remove() please confirm.
> 
>    No, we are good enough without that; I'll consider doing a cleanup
> when/if I have time. :-)
> 
>> Thank you,
>> Claudiu Beznea
> 
> MBR, Sergey

Patch

diff --git a/drivers/net/ethernet/renesas/ravb_main.c b/drivers/net/ethernet/renesas/ravb_main.c
index f4be08f0198d..5bbfdfeef8a9 100644
--- a/drivers/net/ethernet/renesas/ravb_main.c
+++ b/drivers/net/ethernet/renesas/ravb_main.c
@@ -1939,16 +1939,21 @@  static int ravb_open(struct net_device *ndev)
 {
 	struct ravb_private *priv = netdev_priv(ndev);
 	const struct ravb_hw_info *info = priv->info;
+	struct device *dev = &priv->pdev->dev;
 	int error;
 
 	napi_enable(&priv->napi[RAVB_BE]);
 	if (info->nc_queues)
 		napi_enable(&priv->napi[RAVB_NC]);
 
+	error = pm_runtime_resume_and_get(dev);
+	if (error < 0)
+		goto out_napi_off;
+
 	/* Set AVB config mode */
 	error = ravb_set_config_mode(ndev);
 	if (error)
-		goto out_napi_off;
+		goto out_rpm_put;
 
 	ravb_set_delay_mode(ndev);
 	ravb_write(ndev, priv->desc_bat_dma, DBAT);
@@ -1982,6 +1987,9 @@  static int ravb_open(struct net_device *ndev)
 	ravb_stop_dma(ndev);
 out_set_reset:
 	ravb_set_opmode(ndev, CCC_OPC_RESET);
+out_rpm_put:
+	pm_runtime_mark_last_busy(dev);
+	pm_runtime_put_autosuspend(dev);
 out_napi_off:
 	if (info->nc_queues)
 		napi_disable(&priv->napi[RAVB_NC]);
@@ -2322,6 +2330,8 @@  static int ravb_close(struct net_device *ndev)
 	struct ravb_private *priv = netdev_priv(ndev);
 	const struct ravb_hw_info *info = priv->info;
 	struct ravb_tstamp_skb *ts_skb, *ts_skb2;
+	struct device *dev = &priv->pdev->dev;
+	int error;
 
 	netif_tx_stop_all_queues(ndev);
 
@@ -2371,7 +2381,14 @@  static int ravb_close(struct net_device *ndev)
 	ravb_get_stats(ndev);
 
 	/* Set reset mode. */
-	return ravb_set_opmode(ndev, CCC_OPC_RESET);
+	error = ravb_set_opmode(ndev, CCC_OPC_RESET);
+	if (error)
+		return error;
+
+	pm_runtime_mark_last_busy(dev);
+	pm_runtime_put_autosuspend(dev);
+
+	return 0;
 }
 
 static int ravb_hwtstamp_get(struct net_device *ndev, struct ifreq *req)
@@ -2931,6 +2948,8 @@  static int ravb_probe(struct platform_device *pdev)
 	clk_prepare(priv->refclk);
 
 	platform_set_drvdata(pdev, ndev);
+	pm_runtime_set_autosuspend_delay(&pdev->dev, 100);
+	pm_runtime_use_autosuspend(&pdev->dev);
 	pm_runtime_enable(&pdev->dev);
 	error = pm_runtime_resume_and_get(&pdev->dev);
 	if (error < 0)
@@ -3036,6 +3055,9 @@  static int ravb_probe(struct platform_device *pdev)
 	netdev_info(ndev, "Base address at %#x, %pM, IRQ %d.\n",
 		    (u32)ndev->base_addr, ndev->dev_addr, ndev->irq);
 
+	pm_runtime_mark_last_busy(&pdev->dev);
+	pm_runtime_put_autosuspend(&pdev->dev);
+
 	return 0;
 
 out_napi_del:
@@ -3053,6 +3075,7 @@  static int ravb_probe(struct platform_device *pdev)
 	pm_runtime_put(&pdev->dev);
 out_rpm_disable:
 	pm_runtime_disable(&pdev->dev);
+	pm_runtime_dont_use_autosuspend(&pdev->dev);
 	clk_unprepare(priv->refclk);
 out_reset_assert:
 	reset_control_assert(rstc);
@@ -3066,6 +3089,12 @@  static void ravb_remove(struct platform_device *pdev)
 	struct net_device *ndev = platform_get_drvdata(pdev);
 	struct ravb_private *priv = netdev_priv(ndev);
 	const struct ravb_hw_info *info = priv->info;
+	struct device *dev = &priv->pdev->dev;
+	int error;
+
+	error = pm_runtime_resume_and_get(dev);
+	if (error < 0)
+		return;
 
 	unregister_netdev(ndev);
 	if (info->nc_queues)
@@ -3077,8 +3106,9 @@  static void ravb_remove(struct platform_device *pdev)
 	dma_free_coherent(ndev->dev.parent, priv->desc_bat_size, priv->desc_bat,
 			  priv->desc_bat_dma);
 
-	pm_runtime_put_sync(&pdev->dev);
+	pm_runtime_put_sync_suspend(&pdev->dev);
 	pm_runtime_disable(&pdev->dev);
+	pm_runtime_dont_use_autosuspend(dev);
 	clk_unprepare(priv->refclk);
 	reset_control_assert(priv->rstc);
 	free_netdev(ndev);
@@ -3160,6 +3190,10 @@  static int ravb_suspend(struct device *dev)
 	if (ret)
 		return ret;
 
+	ret = pm_runtime_force_suspend(&priv->pdev->dev);
+	if (ret)
+		return ret;
+
 reset_assert:
 	return reset_control_assert(priv->rstc);
 }
@@ -3182,16 +3216,28 @@  static int ravb_resume(struct device *dev)
 		ret = ravb_wol_restore(ndev);
 		if (ret)
 			return ret;
+	} else {
+		ret = pm_runtime_force_resume(dev);
+		if (ret)
+			return ret;
 	}
 
 	/* Reopening the interface will restore the device to the working state. */
 	ret = ravb_open(ndev);
 	if (ret < 0)
-		return ret;
+		goto out_rpm_put;
 
 	ravb_set_rx_mode(ndev);
 	netif_device_attach(ndev);
 
+	return 0;
+
+out_rpm_put:
+	if (!priv->wol_enabled) {
+		pm_runtime_mark_last_busy(dev);
+		pm_runtime_put_autosuspend(dev);
+	}
+
 	return ret;
 }