2021-05-10 05:11:50

by Aswath Govindraju

[permalink] [raw]
Subject: [PATCH v6 1/3] phy: core: Reword the comment specifying the units of max_link_rate to be Mbps

In some subsystems (eg. CAN, SPI), the max link rate supported can be less
than 1 Mbps and if the unit for max_link_rate is Mbps then it can't be
used. Therefore, leave the decision of units to be used, to the producer
and consumer.

Signed-off-by: Aswath Govindraju <[email protected]>
Acked-by: Marc Kleine-Budde <[email protected]>
---
include/linux/phy/phy.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/linux/phy/phy.h b/include/linux/phy/phy.h
index 0ed434d02196..f3286f4cd306 100644
--- a/include/linux/phy/phy.h
+++ b/include/linux/phy/phy.h
@@ -125,7 +125,7 @@ struct phy_ops {
/**
* struct phy_attrs - represents phy attributes
* @bus_width: Data path width implemented by PHY
- * @max_link_rate: Maximum link rate supported by PHY (in Mbps)
+ * @max_link_rate: Maximum link rate supported by PHY (units to be decided by producer and consumer)
* @mode: PHY mode
*/
struct phy_attrs {
--
2.17.1


2021-05-31 07:21:48

by Vinod Koul

[permalink] [raw]
Subject: Re: [PATCH v6 1/3] phy: core: Reword the comment specifying the units of max_link_rate to be Mbps

On 10-05-21, 10:40, Aswath Govindraju wrote:
> In some subsystems (eg. CAN, SPI), the max link rate supported can be less
> than 1 Mbps and if the unit for max_link_rate is Mbps then it can't be
> used. Therefore, leave the decision of units to be used, to the producer
> and consumer.
>
> Signed-off-by: Aswath Govindraju <[email protected]>
> Acked-by: Marc Kleine-Budde <[email protected]>
> ---
> include/linux/phy/phy.h | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/include/linux/phy/phy.h b/include/linux/phy/phy.h
> index 0ed434d02196..f3286f4cd306 100644
> --- a/include/linux/phy/phy.h
> +++ b/include/linux/phy/phy.h
> @@ -125,7 +125,7 @@ struct phy_ops {
> /**
> * struct phy_attrs - represents phy attributes
> * @bus_width: Data path width implemented by PHY
> - * @max_link_rate: Maximum link rate supported by PHY (in Mbps)
> + * @max_link_rate: Maximum link rate supported by PHY (units to be decided by producer and consumer)

So there are a few users of max_link_rate. It would be better that we
document all previous users of max_link_rate that unit is in Mbps and
then modify it here

--
~Vinod

2021-05-31 08:37:29

by Aswath Govindraju

[permalink] [raw]
Subject: Re: [PATCH v6 1/3] phy: core: Reword the comment specifying the units of max_link_rate to be Mbps

Hi Vinod,

On 31/05/21 12:48 pm, Vinod Koul wrote:
> On 10-05-21, 10:40, Aswath Govindraju wrote:
>> In some subsystems (eg. CAN, SPI), the max link rate supported can be less
>> than 1 Mbps and if the unit for max_link_rate is Mbps then it can't be
>> used. Therefore, leave the decision of units to be used, to the producer
>> and consumer.
>>
>> Signed-off-by: Aswath Govindraju <[email protected]>
>> Acked-by: Marc Kleine-Budde <[email protected]>
>> ---
>> include/linux/phy/phy.h | 2 +-
>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/include/linux/phy/phy.h b/include/linux/phy/phy.h
>> index 0ed434d02196..f3286f4cd306 100644
>> --- a/include/linux/phy/phy.h
>> +++ b/include/linux/phy/phy.h
>> @@ -125,7 +125,7 @@ struct phy_ops {
>> /**
>> * struct phy_attrs - represents phy attributes
>> * @bus_width: Data path width implemented by PHY
>> - * @max_link_rate: Maximum link rate supported by PHY (in Mbps)
>> + * @max_link_rate: Maximum link rate supported by PHY (units to be decided by producer and consumer)
>
> So there are a few users of max_link_rate. It would be better that we
> document all previous users of max_link_rate that unit is in Mbps and
> then modify it here
>

I was able to see that the max_link_rate attribute was used at,

drivers/phy/cadence/phy-cadence-torrent.c:2514:
gphy->attrs.max_link_rate = cdns_phy->max_bit_rate;

and in the bindings there is indication that the units to be used is Mbps.

Can you please point me if there is any other place that I might have
missed to look at or that might need documentation update?

Thanks,
Aswath


2021-06-11 12:46:01

by Aswath Govindraju

[permalink] [raw]
Subject: Re: [PATCH v6 1/3] phy: core: Reword the comment specifying the units of max_link_rate to be Mbps

Hi Vinod,

On 31/05/21 2:04 pm, Aswath Govindraju wrote:
> Hi Vinod,
>
> On 31/05/21 12:48 pm, Vinod Koul wrote:
>> On 10-05-21, 10:40, Aswath Govindraju wrote:
>>> In some subsystems (eg. CAN, SPI), the max link rate supported can be less
>>> than 1 Mbps and if the unit for max_link_rate is Mbps then it can't be
>>> used. Therefore, leave the decision of units to be used, to the producer
>>> and consumer.
>>>
>>> Signed-off-by: Aswath Govindraju <[email protected]>
>>> Acked-by: Marc Kleine-Budde <[email protected]>
>>> ---
>>> include/linux/phy/phy.h | 2 +-
>>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>>
>>> diff --git a/include/linux/phy/phy.h b/include/linux/phy/phy.h
>>> index 0ed434d02196..f3286f4cd306 100644
>>> --- a/include/linux/phy/phy.h
>>> +++ b/include/linux/phy/phy.h
>>> @@ -125,7 +125,7 @@ struct phy_ops {
>>> /**
>>> * struct phy_attrs - represents phy attributes
>>> * @bus_width: Data path width implemented by PHY
>>> - * @max_link_rate: Maximum link rate supported by PHY (in Mbps)
>>> + * @max_link_rate: Maximum link rate supported by PHY (units to be decided by producer and consumer)
>>
>> So there are a few users of max_link_rate. It would be better that we
>> document all previous users of max_link_rate that unit is in Mbps and
>> then modify it here
>>
>
> I was able to see that the max_link_rate attribute was used at,
>
> drivers/phy/cadence/phy-cadence-torrent.c:2514:
> gphy->attrs.max_link_rate = cdns_phy->max_bit_rate;
>
> and in the bindings there is indication that the units to be used is Mbps.
>
> Can you please point me if there is any other place that I might have
> missed to look at or that might need documentation update?
>

May I know if this patch series is good to be merged ?

Thanks,
Aswath

> Thanks,
> Aswath
>
>

2021-06-11 13:06:30

by Kishon Vijay Abraham I

[permalink] [raw]
Subject: Re: [PATCH v6 1/3] phy: core: Reword the comment specifying the units of max_link_rate to be Mbps

Hi,

On 11/06/21 6:12 pm, Aswath Govindraju wrote:
> Hi Vinod,
>
> On 31/05/21 2:04 pm, Aswath Govindraju wrote:
>> Hi Vinod,
>>
>> On 31/05/21 12:48 pm, Vinod Koul wrote:
>>> On 10-05-21, 10:40, Aswath Govindraju wrote:
>>>> In some subsystems (eg. CAN, SPI), the max link rate supported can be less
>>>> than 1 Mbps and if the unit for max_link_rate is Mbps then it can't be
>>>> used. Therefore, leave the decision of units to be used, to the producer
>>>> and consumer.
>>>>
>>>> Signed-off-by: Aswath Govindraju <[email protected]>
>>>> Acked-by: Marc Kleine-Budde <[email protected]>
>>>> ---
>>>> include/linux/phy/phy.h | 2 +-
>>>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>>>
>>>> diff --git a/include/linux/phy/phy.h b/include/linux/phy/phy.h
>>>> index 0ed434d02196..f3286f4cd306 100644
>>>> --- a/include/linux/phy/phy.h
>>>> +++ b/include/linux/phy/phy.h
>>>> @@ -125,7 +125,7 @@ struct phy_ops {
>>>> /**
>>>> * struct phy_attrs - represents phy attributes
>>>> * @bus_width: Data path width implemented by PHY
>>>> - * @max_link_rate: Maximum link rate supported by PHY (in Mbps)
>>>> + * @max_link_rate: Maximum link rate supported by PHY (units to be decided by producer and consumer)
>>>
>>> So there are a few users of max_link_rate. It would be better that we
>>> document all previous users of max_link_rate that unit is in Mbps and
>>> then modify it here
>>>
>>
>> I was able to see that the max_link_rate attribute was used at,
>>
>> drivers/phy/cadence/phy-cadence-torrent.c:2514:
>> gphy->attrs.max_link_rate = cdns_phy->max_bit_rate;
>>
>> and in the bindings there is indication that the units to be used is Mbps.
>>
>> Can you please point me if there is any other place that I might have
>> missed to look at or that might need documentation update?
>>

The only user seems to be Torrent and max_bit_rate is documented well in
Torrent.

Acked-by: Kishon Vijay Abraham I <[email protected]>

Thanks
Kishon