2023-12-14 21:04:26

by Sergey Shtylyov

[permalink] [raw]
Subject: Re: [PATCH net-next v2 11/21] net: ravb: Move DBAT configuration to the driver's ndo_open API

On 12/14/23 2:45 PM, Claudiu wrote:

> From: Claudiu Beznea <[email protected]>
>
> DBAT setup was done in the driver's probe API. As some IP variants switch
> to reset mode (and thus registers' content is lost) when setting clocks
> (due to module standby functionality) to be able to implement runtime PM
> move the DBAT configuration in the driver's ndo_open API.
>
> This commit prepares the code for the addition of runtime PM.
>
> Signed-off-by: Claudiu Beznea <[email protected]>

Reviewed-by: Sergey Shtylyov <[email protected]>

[...]
> diff --git a/drivers/net/ethernet/renesas/ravb_main.c b/drivers/net/ethernet/renesas/ravb_main.c
> index 04eaa1967651..6b8ca08be35e 100644
> --- a/drivers/net/ethernet/renesas/ravb_main.c
> +++ b/drivers/net/ethernet/renesas/ravb_main.c
> @@ -1822,6 +1822,7 @@ static int ravb_open(struct net_device *ndev)
> napi_enable(&priv->napi[RAVB_NC]);
>
> ravb_set_delay_mode(ndev);
> + ravb_write(ndev, priv->desc_bat_dma, DBAT);
>
> /* Device init */
> error = ravb_dmac_init(ndev);
> @@ -2841,7 +2842,6 @@ static int ravb_probe(struct platform_device *pdev)
> }
> for (q = RAVB_BE; q < DBAT_ENTRY_NUM; q++)
> priv->desc_bat[q].die_dt = DT_EOS;
> - ravb_write(ndev, priv->desc_bat_dma, DBAT);
>
> /* Initialise HW timestamp list */
> INIT_LIST_HEAD(&priv->ts_skb_list);
>

How about also removing the DBAT write from ravb_resume()?

MBR, Sergey


2023-12-15 20:12:45

by Sergey Shtylyov

[permalink] [raw]
Subject: Re: [PATCH net-next v2 11/21] net: ravb: Move DBAT configuration to the driver's ndo_open API

On 12/15/23 12:03 AM, Sergey Shtylyov wrote:
[...]

>> From: Claudiu Beznea <[email protected]>
>>
>> DBAT setup was done in the driver's probe API. As some IP variants switch
>> to reset mode (and thus registers' content is lost) when setting clocks
>> (due to module standby functionality) to be able to implement runtime PM
>> move the DBAT configuration in the driver's ndo_open API.
>>
>> This commit prepares the code for the addition of runtime PM.
>>
>> Signed-off-by: Claudiu Beznea <[email protected]>
>
> Reviewed-by: Sergey Shtylyov <[email protected]>
>
> [...]
>> diff --git a/drivers/net/ethernet/renesas/ravb_main.c b/drivers/net/ethernet/renesas/ravb_main.c
>> index 04eaa1967651..6b8ca08be35e 100644
>> --- a/drivers/net/ethernet/renesas/ravb_main.c
>> +++ b/drivers/net/ethernet/renesas/ravb_main.c
>> @@ -1822,6 +1822,7 @@ static int ravb_open(struct net_device *ndev)
>> napi_enable(&priv->napi[RAVB_NC]);
>>
>> ravb_set_delay_mode(ndev);
>> + ravb_write(ndev, priv->desc_bat_dma, DBAT);

Looking at it again, I suspect this belong in ravb_dmac_init()...

>>
>> /* Device init */
>> error = ravb_dmac_init(ndev);
[...]

MBR, Sergey

2023-12-17 12:54:34

by Claudiu

[permalink] [raw]
Subject: Re: [PATCH net-next v2 11/21] net: ravb: Move DBAT configuration to the driver's ndo_open API



On 15.12.2023 22:01, Sergey Shtylyov wrote:
> On 12/15/23 12:03 AM, Sergey Shtylyov wrote:
> [...]
>
>>> From: Claudiu Beznea <[email protected]>
>>>
>>> DBAT setup was done in the driver's probe API. As some IP variants switch
>>> to reset mode (and thus registers' content is lost) when setting clocks
>>> (due to module standby functionality) to be able to implement runtime PM
>>> move the DBAT configuration in the driver's ndo_open API.
>>>
>>> This commit prepares the code for the addition of runtime PM.
>>>
>>> Signed-off-by: Claudiu Beznea <[email protected]>
>>
>> Reviewed-by: Sergey Shtylyov <[email protected]>
>>
>> [...]
>>> diff --git a/drivers/net/ethernet/renesas/ravb_main.c b/drivers/net/ethernet/renesas/ravb_main.c
>>> index 04eaa1967651..6b8ca08be35e 100644
>>> --- a/drivers/net/ethernet/renesas/ravb_main.c
>>> +++ b/drivers/net/ethernet/renesas/ravb_main.c
>>> @@ -1822,6 +1822,7 @@ static int ravb_open(struct net_device *ndev)
>>> napi_enable(&priv->napi[RAVB_NC]);
>>>
>>> ravb_set_delay_mode(ndev);
>>> + ravb_write(ndev, priv->desc_bat_dma, DBAT);
>
> Looking at it again, I suspect this belong in ravb_dmac_init()...

ravb_dmac_init() is called from multiple places in this driver, e.g.,
ravb_set_ringparam(), ravb_tx_timeout_work(). I'm afraid we may broke the
behavior of these if DBAT setup is moved in ravb_dmac_init(). This is also
valid for setting delay (see patch 10/12).

>
>>>
>>> /* Device init */
>>> error = ravb_dmac_init(ndev);
> [...]
>
> MBR, Sergey

2023-12-19 18:55:15

by Sergey Shtylyov

[permalink] [raw]
Subject: Re: [PATCH net-next v2 11/21] net: ravb: Move DBAT configuration to the driver's ndo_open API

On 12/17/23 3:54 PM, claudiu beznea wrote:

[...]

>>>> From: Claudiu Beznea <[email protected]>
>>>>
>>>> DBAT setup was done in the driver's probe API. As some IP variants switch
>>>> to reset mode (and thus registers' content is lost) when setting clocks
>>>> (due to module standby functionality) to be able to implement runtime PM
>>>> move the DBAT configuration in the driver's ndo_open API.
>>>>
>>>> This commit prepares the code for the addition of runtime PM.
>>>>
>>>> Signed-off-by: Claudiu Beznea <[email protected]>
>>>
>>> Reviewed-by: Sergey Shtylyov <[email protected]>
>>>
>>> [...]
>>>> diff --git a/drivers/net/ethernet/renesas/ravb_main.c b/drivers/net/ethernet/renesas/ravb_main.c
>>>> index 04eaa1967651..6b8ca08be35e 100644
>>>> --- a/drivers/net/ethernet/renesas/ravb_main.c
>>>> +++ b/drivers/net/ethernet/renesas/ravb_main.c
>>>> @@ -1822,6 +1822,7 @@ static int ravb_open(struct net_device *ndev)
>>>> napi_enable(&priv->napi[RAVB_NC]);
>>>>
>>>> ravb_set_delay_mode(ndev);
>>>> + ravb_write(ndev, priv->desc_bat_dma, DBAT);
>>
>> Looking at it again, I suspect this belong in ravb_dmac_init()...
>
> ravb_dmac_init() is called from multiple places in this driver, e.g.,

It's purpose is to configure AVB-DMAC and DBAT is the AVB-DMAC register,
right?

> ravb_set_ringparam(), ravb_tx_timeout_work().

I know. Its value is only calculated once, in ravb_probe(), right?

> I'm afraid we may broke the behavior of these if DBAT setup is moved

Do not be afraid! :-)

> in ravb_dmac_init(). This is also
> valid for setting delay (see patch 10/12).

I don't think there will be a problem either... but maybe we
should call it in ravb_emac_init() indeed.

[...]

MBR, Sergey

2023-12-20 11:41:57

by Claudiu

[permalink] [raw]
Subject: Re: [PATCH net-next v2 11/21] net: ravb: Move DBAT configuration to the driver's ndo_open API



On 19.12.2023 20:54, Sergey Shtylyov wrote:
> On 12/17/23 3:54 PM, claudiu beznea wrote:
>
> [...]
>
>>>>> From: Claudiu Beznea <[email protected]>
>>>>>
>>>>> DBAT setup was done in the driver's probe API. As some IP variants switch
>>>>> to reset mode (and thus registers' content is lost) when setting clocks
>>>>> (due to module standby functionality) to be able to implement runtime PM
>>>>> move the DBAT configuration in the driver's ndo_open API.
>>>>>
>>>>> This commit prepares the code for the addition of runtime PM.
>>>>>
>>>>> Signed-off-by: Claudiu Beznea <[email protected]>
>>>>
>>>> Reviewed-by: Sergey Shtylyov <[email protected]>
>>>>
>>>> [...]
>>>>> diff --git a/drivers/net/ethernet/renesas/ravb_main.c b/drivers/net/ethernet/renesas/ravb_main.c
>>>>> index 04eaa1967651..6b8ca08be35e 100644
>>>>> --- a/drivers/net/ethernet/renesas/ravb_main.c
>>>>> +++ b/drivers/net/ethernet/renesas/ravb_main.c
>>>>> @@ -1822,6 +1822,7 @@ static int ravb_open(struct net_device *ndev)
>>>>> napi_enable(&priv->napi[RAVB_NC]);
>>>>>
>>>>> ravb_set_delay_mode(ndev);
>>>>> + ravb_write(ndev, priv->desc_bat_dma, DBAT);
>>>
>>> Looking at it again, I suspect this belong in ravb_dmac_init()...
>>
>> ravb_dmac_init() is called from multiple places in this driver, e.g.,
>
> It's purpose is to configure AVB-DMAC and DBAT is the AVB-DMAC register,
> right?

It is. But it is pointless to configure it more than one time after
ravb_open() has been called as the register content is not changed until IP
enters reset mode (though ravb_close() now).

>
>> ravb_set_ringparam(), ravb_tx_timeout_work().
>
> I know. Its value is only calculated once, in ravb_probe(), right?

right

>
>> I'm afraid we may broke the behavior of these if DBAT setup is moved

I was wrong here. DBAT is not changed by IP while TX/RX is working.

>
> Do not be afraid! :-)
>
>> in ravb_dmac_init(). This is also
>> valid for setting delay (see patch 10/12).
>
> I don't think there will be a problem either... but maybe we
> should call it in ravb_emac_init() indeed.
>
> [...]
>
> MBR, Sergey

2023-12-21 19:55:17

by Sergey Shtylyov

[permalink] [raw]
Subject: Re: [PATCH net-next v2 11/21] net: ravb: Move DBAT configuration to the driver's ndo_open API

On 12/20/23 2:41 PM, claudiu beznea wrote:

[...]

>>>>>> From: Claudiu Beznea <[email protected]>
>>>>>>
>>>>>> DBAT setup was done in the driver's probe API. As some IP variants switch
>>>>>> to reset mode (and thus registers' content is lost) when setting clocks
>>>>>> (due to module standby functionality) to be able to implement runtime PM
>>>>>> move the DBAT configuration in the driver's ndo_open API.
>>>>>>
>>>>>> This commit prepares the code for the addition of runtime PM.
>>>>>>
>>>>>> Signed-off-by: Claudiu Beznea <[email protected]>
>>>>>
>>>>> Reviewed-by: Sergey Shtylyov <[email protected]>
>>>>>
>>>>> [...]
>>>>>> diff --git a/drivers/net/ethernet/renesas/ravb_main.c b/drivers/net/ethernet/renesas/ravb_main.c
>>>>>> index 04eaa1967651..6b8ca08be35e 100644
>>>>>> --- a/drivers/net/ethernet/renesas/ravb_main.c
>>>>>> +++ b/drivers/net/ethernet/renesas/ravb_main.c
>>>>>> @@ -1822,6 +1822,7 @@ static int ravb_open(struct net_device *ndev)
>>>>>> napi_enable(&priv->napi[RAVB_NC]);
>>>>>>
>>>>>> ravb_set_delay_mode(ndev);
>>>>>> + ravb_write(ndev, priv->desc_bat_dma, DBAT);
>>>>
>>>> Looking at it again, I suspect this belong in ravb_dmac_init()...
>>>
>>> ravb_dmac_init() is called from multiple places in this driver, e.g.,
>>
>> It's purpose is to configure AVB-DMAC and DBAT is the AVB-DMAC register,
>> right?
>
> It is. But it is pointless to configure it more than one time after
> ravb_open() has been called as the register content is not changed until IP
> enters reset mode (though ravb_close() now).

The same is true for the most registers set by ravb_dmac_init()!

[...]

MBR, Sergey