diff mbox series

[08/13] net: ravb: Rely on PM domain to enable refclk

Message ID 20231120084606.4083194-9-claudiu.beznea.uj@bp.renesas.com (mailing list archive)
State Superseded
Delegated to: Geert Uytterhoeven
Headers show
Series net: ravb: Add suspend to RAM and runtime PM support for RZ/G3S | expand

Commit Message

Claudiu Beznea Nov. 20, 2023, 8:46 a.m. UTC
From: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>

For RZ/G3S and RZ/G2L SoCs the Ethernet's reference clock is part of the
Ethernet's power domain. It is controlled though CPG driver that is
providing the support for power domain that Ethernet belongs. Thus,
to be able to implement runtime PM (at least for RZ/G3S at the moment)
w/o the need to add clock enable/disable specific calls in runtime PM
ops of ravb driver and interfere with other IP specific implementations,
add a new variable to struct_hw_info and enable the reference clock
based on the value of this variable (the variable states if reference
clock is part of the Ethernet's power domain).

Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
---
 drivers/net/ethernet/renesas/ravb.h      |  1 +
 drivers/net/ethernet/renesas/ravb_main.c | 19 ++++++++++++-------
 2 files changed, 13 insertions(+), 7 deletions(-)

Comments

Sergey Shtylyov Nov. 22, 2023, 5:31 p.m. UTC | #1
On 11/20/23 11:46 AM, Claudiu wrote:

> From: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
> 
> For RZ/G3S and RZ/G2L SoCs the Ethernet's reference clock is part of the
> Ethernet's power domain. It is controlled though CPG driver that is
> providing the support for power domain that Ethernet belongs. Thus,
> to be able to implement runtime PM (at least for RZ/G3S at the moment)
> w/o the need to add clock enable/disable specific calls in runtime PM
> ops of ravb driver and interfere with other IP specific implementations,
> add a new variable to struct_hw_info and enable the reference clock
> based on the value of this variable (the variable states if reference
> clock is part of the Ethernet's power domain).
> 
> Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>

Reviewed-by: Sergey Shtylyov <s.shtylyov@omp.ru>

[...]

MBR, Sergey
Geert Uytterhoeven Nov. 23, 2023, 8:48 a.m. UTC | #2
Hi Claudiu,

Thanks for your patch (which seems to have been delayed by 3 days, ouch)!

On Thu, Nov 23, 2023 at 5:35 AM Claudiu <claudiu.beznea@tuxon.dev> wrote:
> From: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
>
> For RZ/G3S and RZ/G2L SoCs the Ethernet's reference clock is part of the
> Ethernet's power domain. It is controlled though CPG driver that is
> providing the support for power domain that Ethernet belongs. Thus,
> to be able to implement runtime PM (at least for RZ/G3S at the moment)

Why only for RZ/G3S?

> w/o the need to add clock enable/disable specific calls in runtime PM
> ops of ravb driver and interfere with other IP specific implementations,
> add a new variable to struct_hw_info and enable the reference clock
> based on the value of this variable (the variable states if reference
> clock is part of the Ethernet's power domain).
>
> Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>

> --- a/drivers/net/ethernet/renesas/ravb.h
> +++ b/drivers/net/ethernet/renesas/ravb.h
> @@ -1043,6 +1043,7 @@ struct ravb_hw_info {
>         unsigned nc_queues:1;           /* AVB-DMAC has RX and TX NC queues */
>         unsigned magic_pkt:1;           /* E-MAC supports magic packet detection */
>         unsigned half_duplex:1;         /* E-MAC supports half duplex mode */
> +       unsigned refclk_in_pd:1;        /* Reference clock is part of a power domain. */
>  };
>
>  struct ravb_private {
> diff --git a/drivers/net/ethernet/renesas/ravb_main.c b/drivers/net/ethernet/renesas/ravb_main.c
> index 836fdb4b3bfd..ddd8cd2c0f89 100644
> --- a/drivers/net/ethernet/renesas/ravb_main.c
> +++ b/drivers/net/ethernet/renesas/ravb_main.c
> @@ -2502,6 +2502,7 @@ static const struct ravb_hw_info gbeth_hw_info = {
>         .tx_counters = 1,
>         .carrier_counters = 1,
>         .half_duplex = 1,
> +       .refclk_in_pd = 1,
>  };
>
>  static const struct of_device_id ravb_match_table[] = {
> @@ -2749,12 +2750,14 @@ static int ravb_probe(struct platform_device *pdev)
>                 goto out_release;
>         }
>
> -       priv->refclk = devm_clk_get_optional(&pdev->dev, "refclk");
> -       if (IS_ERR(priv->refclk)) {
> -               error = PTR_ERR(priv->refclk);
> -               goto out_release;
> +       if (!info->refclk_in_pd) {
> +               priv->refclk = devm_clk_get_optional(&pdev->dev, "refclk");
> +               if (IS_ERR(priv->refclk)) {
> +                       error = PTR_ERR(priv->refclk);
> +                       goto out_release;
> +               }
> +               clk_prepare_enable(priv->refclk);
>         }
> -       clk_prepare_enable(priv->refclk);

Is this patch really needed? It doesn't hurt to manually enable a
clock that is also under Runtime PM control.  Clock prepare/enable
refcounting will take care of that.

>
>         if (info->gptp_ref_clk) {
>                 priv->gptp_clk = devm_clk_get(&pdev->dev, "gptp");
> @@ -2869,7 +2872,8 @@ static int ravb_probe(struct platform_device *pdev)
>         if (info->ccc_gac)
>                 ravb_ptp_stop(ndev);
>  out_disable_refclk:
> -       clk_disable_unprepare(priv->refclk);
> +       if (!info->refclk_in_pd)
> +               clk_disable_unprepare(priv->refclk);
>  out_release:
>         free_netdev(ndev);
>  pm_runtime_put:
> @@ -2890,7 +2894,8 @@ static void ravb_remove(struct platform_device *pdev)
>         if (info->ccc_gac)
>                 ravb_ptp_stop(ndev);
>
> -       clk_disable_unprepare(priv->refclk);
> +       if (!info->refclk_in_pd)
> +               clk_disable_unprepare(priv->refclk);
>
>         /* Set reset mode */
>         ravb_write(ndev, CCC_OPC_RESET, CCC);

Gr{oetje,eeting}s,

                        Geert


--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds
Claudiu Beznea Nov. 23, 2023, 5:10 p.m. UTC | #3
Hi, Geert,

On 23.11.2023 10:48, Geert Uytterhoeven wrote:
> Hi Claudiu,
> 
> Thanks for your patch (which seems to have been delayed by 3 days, ouch)!
> 
> On Thu, Nov 23, 2023 at 5:35 AM Claudiu <claudiu.beznea@tuxon.dev> wrote:
>> From: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
>>
>> For RZ/G3S and RZ/G2L SoCs the Ethernet's reference clock is part of the
>> Ethernet's power domain. It is controlled though CPG driver that is
>> providing the support for power domain that Ethernet belongs. Thus,
>> to be able to implement runtime PM (at least for RZ/G3S at the moment)
> 
> Why only for RZ/G3S?

(I'm copy pasting here what I already replied to Sergey)

The reasons I've limited only to RZ/G3S are:
1/ I don't have all the platforms to test it
2/ on G1H this doesn't work. I tried to debugged it but I don't have a
   platform at hand, only remotely, and is hardly to debug once the
   ethernet fails to work: probe is working(), open is executed, PHY is
   initialized and then TX/RX is not working... don't know why ATM.

> 
>> w/o the need to add clock enable/disable specific calls in runtime PM
>> ops of ravb driver and interfere with other IP specific implementations,
>> add a new variable to struct_hw_info and enable the reference clock
>> based on the value of this variable (the variable states if reference
>> clock is part of the Ethernet's power domain).
>>
>> Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
> 
>> --- a/drivers/net/ethernet/renesas/ravb.h
>> +++ b/drivers/net/ethernet/renesas/ravb.h
>> @@ -1043,6 +1043,7 @@ struct ravb_hw_info {
>>         unsigned nc_queues:1;           /* AVB-DMAC has RX and TX NC queues */
>>         unsigned magic_pkt:1;           /* E-MAC supports magic packet detection */
>>         unsigned half_duplex:1;         /* E-MAC supports half duplex mode */
>> +       unsigned refclk_in_pd:1;        /* Reference clock is part of a power domain. */
>>  };
>>
>>  struct ravb_private {
>> diff --git a/drivers/net/ethernet/renesas/ravb_main.c b/drivers/net/ethernet/renesas/ravb_main.c
>> index 836fdb4b3bfd..ddd8cd2c0f89 100644
>> --- a/drivers/net/ethernet/renesas/ravb_main.c
>> +++ b/drivers/net/ethernet/renesas/ravb_main.c
>> @@ -2502,6 +2502,7 @@ static const struct ravb_hw_info gbeth_hw_info = {
>>         .tx_counters = 1,
>>         .carrier_counters = 1,
>>         .half_duplex = 1,
>> +       .refclk_in_pd = 1,
>>  };
>>
>>  static const struct of_device_id ravb_match_table[] = {
>> @@ -2749,12 +2750,14 @@ static int ravb_probe(struct platform_device *pdev)
>>                 goto out_release;
>>         }
>>
>> -       priv->refclk = devm_clk_get_optional(&pdev->dev, "refclk");
>> -       if (IS_ERR(priv->refclk)) {
>> -               error = PTR_ERR(priv->refclk);
>> -               goto out_release;
>> +       if (!info->refclk_in_pd) {
>> +               priv->refclk = devm_clk_get_optional(&pdev->dev, "refclk");
>> +               if (IS_ERR(priv->refclk)) {
>> +                       error = PTR_ERR(priv->refclk);
>> +                       goto out_release;
>> +               }
>> +               clk_prepare_enable(priv->refclk);
>>         }
>> -       clk_prepare_enable(priv->refclk);
> 
> Is this patch really needed? It doesn't hurt to manually enable a
> clock that is also under Runtime PM control.  Clock prepare/enable
> refcounting will take care of that.

I agree with that. I chose this path to not interfere w/ the comments
ravb_runtime_nop() which I didn't understand. Also I fail to understand why
the ravb_runtime_nop() is there...

> 
>>
>>         if (info->gptp_ref_clk) {
>>                 priv->gptp_clk = devm_clk_get(&pdev->dev, "gptp");
>> @@ -2869,7 +2872,8 @@ static int ravb_probe(struct platform_device *pdev)
>>         if (info->ccc_gac)
>>                 ravb_ptp_stop(ndev);
>>  out_disable_refclk:
>> -       clk_disable_unprepare(priv->refclk);
>> +       if (!info->refclk_in_pd)
>> +               clk_disable_unprepare(priv->refclk);
>>  out_release:
>>         free_netdev(ndev);
>>  pm_runtime_put:
>> @@ -2890,7 +2894,8 @@ static void ravb_remove(struct platform_device *pdev)
>>         if (info->ccc_gac)
>>                 ravb_ptp_stop(ndev);
>>
>> -       clk_disable_unprepare(priv->refclk);
>> +       if (!info->refclk_in_pd)
>> +               clk_disable_unprepare(priv->refclk);
>>
>>         /* Set reset mode */
>>         ravb_write(ndev, CCC_OPC_RESET, CCC);
> 
> Gr{oetje,eeting}s,
> 
>                         Geert
> 
> 
> --
> Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
> 
> In personal conversations with technical people, I call myself a hacker. But
> when I'm talking to journalists I just say "programmer" or something like that.
>                                 -- Linus Torvalds
Sergey Shtylyov Nov. 23, 2023, 7:26 p.m. UTC | #4
On 11/23/23 8:10 PM, claudiu beznea wrote:
[...]

>> On Thu, Nov 23, 2023 at 5:35 AM Claudiu <claudiu.beznea@tuxon.dev> wrote:
>>> From: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
[...]
>>> w/o the need to add clock enable/disable specific calls in runtime PM
>>> ops of ravb driver and interfere with other IP specific implementations,
>>> add a new variable to struct_hw_info and enable the reference clock
>>> based on the value of this variable (the variable states if reference
>>> clock is part of the Ethernet's power domain).
>>>
>>> Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>

[...]
>>>  static const struct of_device_id ravb_match_table[] = {
>>> @@ -2749,12 +2750,14 @@ static int ravb_probe(struct platform_device *pdev)
>>>                 goto out_release;
>>>         }
>>>
>>> -       priv->refclk = devm_clk_get_optional(&pdev->dev, "refclk");
>>> -       if (IS_ERR(priv->refclk)) {
>>> -               error = PTR_ERR(priv->refclk);
>>> -               goto out_release;
>>> +       if (!info->refclk_in_pd) {
>>> +               priv->refclk = devm_clk_get_optional(&pdev->dev, "refclk");
>>> +               if (IS_ERR(priv->refclk)) {
>>> +                       error = PTR_ERR(priv->refclk);
>>> +                       goto out_release;
>>> +               }
>>> +               clk_prepare_enable(priv->refclk);
>>>         }
>>> -       clk_prepare_enable(priv->refclk);
>>
>> Is this patch really needed? It doesn't hurt to manually enable a
>> clock that is also under Runtime PM control.  Clock prepare/enable
>> refcounting will take care of that.
> 
> I agree with that. I chose this path to not interfere w/ the comments
> ravb_runtime_nop() which I didn't understand. Also I fail to understand why
> the ravb_runtime_nop() is there...

   Looks like it was blindly copied from the sh_eth driver and doesn't (yet?)
apply to ravb...

[...]

MBR, Sergey
diff mbox series

Patch

diff --git a/drivers/net/ethernet/renesas/ravb.h b/drivers/net/ethernet/renesas/ravb.h
index e0f8276cffed..c2d8d890031f 100644
--- a/drivers/net/ethernet/renesas/ravb.h
+++ b/drivers/net/ethernet/renesas/ravb.h
@@ -1043,6 +1043,7 @@  struct ravb_hw_info {
 	unsigned nc_queues:1;		/* AVB-DMAC has RX and TX NC queues */
 	unsigned magic_pkt:1;		/* E-MAC supports magic packet detection */
 	unsigned half_duplex:1;		/* E-MAC supports half duplex mode */
+	unsigned refclk_in_pd:1;	/* Reference clock is part of a power domain. */
 };
 
 struct ravb_private {
diff --git a/drivers/net/ethernet/renesas/ravb_main.c b/drivers/net/ethernet/renesas/ravb_main.c
index 836fdb4b3bfd..ddd8cd2c0f89 100644
--- a/drivers/net/ethernet/renesas/ravb_main.c
+++ b/drivers/net/ethernet/renesas/ravb_main.c
@@ -2502,6 +2502,7 @@  static const struct ravb_hw_info gbeth_hw_info = {
 	.tx_counters = 1,
 	.carrier_counters = 1,
 	.half_duplex = 1,
+	.refclk_in_pd = 1,
 };
 
 static const struct of_device_id ravb_match_table[] = {
@@ -2749,12 +2750,14 @@  static int ravb_probe(struct platform_device *pdev)
 		goto out_release;
 	}
 
-	priv->refclk = devm_clk_get_optional(&pdev->dev, "refclk");
-	if (IS_ERR(priv->refclk)) {
-		error = PTR_ERR(priv->refclk);
-		goto out_release;
+	if (!info->refclk_in_pd) {
+		priv->refclk = devm_clk_get_optional(&pdev->dev, "refclk");
+		if (IS_ERR(priv->refclk)) {
+			error = PTR_ERR(priv->refclk);
+			goto out_release;
+		}
+		clk_prepare_enable(priv->refclk);
 	}
-	clk_prepare_enable(priv->refclk);
 
 	if (info->gptp_ref_clk) {
 		priv->gptp_clk = devm_clk_get(&pdev->dev, "gptp");
@@ -2869,7 +2872,8 @@  static int ravb_probe(struct platform_device *pdev)
 	if (info->ccc_gac)
 		ravb_ptp_stop(ndev);
 out_disable_refclk:
-	clk_disable_unprepare(priv->refclk);
+	if (!info->refclk_in_pd)
+		clk_disable_unprepare(priv->refclk);
 out_release:
 	free_netdev(ndev);
 pm_runtime_put:
@@ -2890,7 +2894,8 @@  static void ravb_remove(struct platform_device *pdev)
 	if (info->ccc_gac)
 		ravb_ptp_stop(ndev);
 
-	clk_disable_unprepare(priv->refclk);
+	if (!info->refclk_in_pd)
+		clk_disable_unprepare(priv->refclk);
 
 	/* Set reset mode */
 	ravb_write(ndev, CCC_OPC_RESET, CCC);