[PATCH v3] net: phy: meson-gxl: Add generic dummy stubs for MMD register access

[PATCH v3] net: phy: meson-gxl: Add generic dummy stubs for MMD register access

[Chris Healy]

From: Chris Healy <healych@amazon.com>

The Meson G12A Internal PHY does not support standard IEEE MMD extended
register access, therefore add generic dummy stubs to fail the read and
write MMD calls. This is necessary to prevent the core PHY code from
erroneously believing that EEE is supported by this PHY even though this
PHY does not support EEE, as MMD register access returns all FFFFs.

Fixes: 5c3407abb338 ("net: phy: meson-gxl: add g12a support")
Reviewed-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Chris Healy <healych@amazon.com>

---

Changes in v3:
* Add reviewed-by
Change in v2:
* Add fixes tag

 drivers/net/phy/meson-gxl.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/net/phy/meson-gxl.c b/drivers/net/phy/meson-gxl.c
index c49062ad72c6..5e41658b1e2f 100644
--- a/drivers/net/phy/meson-gxl.c
+++ b/drivers/net/phy/meson-gxl.c
@@ -271,6 +271,8 @@ static struct phy_driver meson_gxl_phy[] = {
 		.handle_interrupt = meson_gxl_handle_interrupt,
 		.suspend        = genphy_suspend,
 		.resume         = genphy_resume,
+		.read_mmd	= genphy_read_mmd_unsupported,
+		.write_mmd	= genphy_write_mmd_unsupported,
 	},
 };
 
-- 
2.39.1

Re: [PATCH v3] net: phy: meson-gxl: Add generic dummy stubs for MMD register access

[Jerome Brunet]

On Mon 30 Jan 2023 at 15:14, Chris Healy <cphealy@gmail.com> wrote:

> From: Chris Healy <healych@amazon.com>
>
> The Meson G12A Internal PHY does not support standard IEEE MMD extended
> register access, therefore add generic dummy stubs to fail the read and
> write MMD calls. This is necessary to prevent the core PHY code from
> erroneously believing that EEE is supported by this PHY even though this
> PHY does not support EEE, as MMD register access returns all FFFFs.

This is definitely something that should be done, Thx !

>
> Fixes: 5c3407abb338 ("net: phy: meson-gxl: add g12a support")

This commit does not seems appropriate, especially since only the GXL ops
are changed, not the g12a variant.

This brings a 2nd point, any reason for not changing the g12 variant ?
I'm fairly confident it does support EEE either.

> Reviewed-by: Heiner Kallweit <hkallweit1@gmail.com>
> Signed-off-by: Chris Healy <healych@amazon.com>
>
> ---
>
> Changes in v3:
> * Add reviewed-by
> Change in v2:
> * Add fixes tag
>
>  drivers/net/phy/meson-gxl.c | 2 ++
>  1 file changed, 2 insertions(+)
>
> diff --git a/drivers/net/phy/meson-gxl.c b/drivers/net/phy/meson-gxl.c
> index c49062ad72c6..5e41658b1e2f 100644
> --- a/drivers/net/phy/meson-gxl.c
> +++ b/drivers/net/phy/meson-gxl.c
> @@ -271,6 +271,8 @@ static struct phy_driver meson_gxl_phy[] = {
>  		.handle_interrupt = meson_gxl_handle_interrupt,
>  		.suspend        = genphy_suspend,
>  		.resume         = genphy_resume,
> +		.read_mmd	= genphy_read_mmd_unsupported,
> +		.write_mmd	= genphy_write_mmd_unsupported,
>  	},
>  };

Re: [PATCH v3] net: phy: meson-gxl: Add generic dummy stubs for MMD register access

[Heiner Kallweit]

On 31.01.2023 11:05, Jerome Brunet wrote:
> 
> On Mon 30 Jan 2023 at 15:14, Chris Healy <cphealy@gmail.com> wrote:
> 
>> From: Chris Healy <healych@amazon.com>
>>
>> The Meson G12A Internal PHY does not support standard IEEE MMD extended
>> register access, therefore add generic dummy stubs to fail the read and
>> write MMD calls. This is necessary to prevent the core PHY code from
>> erroneously believing that EEE is supported by this PHY even though this
>> PHY does not support EEE, as MMD register access returns all FFFFs.
> 
> This is definitely something that should be done, Thx !
> 
>>
>> Fixes: 5c3407abb338 ("net: phy: meson-gxl: add g12a support")
> 
> This commit does not seems appropriate, especially since only the GXL ops
> are changed, not the g12a variant.
> 
The diff is a little bit misleading. The patch affects the G12A PHY.

> This brings a 2nd point, any reason for not changing the g12 variant ?
> I'm fairly confident it does support EEE either.
> 
Supposedly it's a typo and you mean "doesn't". Neither Chris nor me
have GXL HW and we didn't want to submit a patch just based on speculation.

>> Reviewed-by: Heiner Kallweit <hkallweit1@gmail.com>
>> Signed-off-by: Chris Healy <healych@amazon.com>
>>
>> ---
>>
>> Changes in v3:
>> * Add reviewed-by
>> Change in v2:
>> * Add fixes tag
>>
>>  drivers/net/phy/meson-gxl.c | 2 ++
>>  1 file changed, 2 insertions(+)
>>
>> diff --git a/drivers/net/phy/meson-gxl.c b/drivers/net/phy/meson-gxl.c
>> index c49062ad72c6..5e41658b1e2f 100644
>> --- a/drivers/net/phy/meson-gxl.c
>> +++ b/drivers/net/phy/meson-gxl.c
>> @@ -271,6 +271,8 @@ static struct phy_driver meson_gxl_phy[] = {
>>  		.handle_interrupt = meson_gxl_handle_interrupt,
>>  		.suspend        = genphy_suspend,
>>  		.resume         = genphy_resume,
>> +		.read_mmd	= genphy_read_mmd_unsupported,
>> +		.write_mmd	= genphy_write_mmd_unsupported,
>>  	},
>>  };
> 

Re: [PATCH v3] net: phy: meson-gxl: Add generic dummy stubs for MMD register access

[Jerome Brunet]

On Tue 31 Jan 2023 at 11:38, Heiner Kallweit <hkallweit1@gmail.com> wrote:

> On 31.01.2023 11:05, Jerome Brunet wrote:
>> 
>> On Mon 30 Jan 2023 at 15:14, Chris Healy <cphealy@gmail.com> wrote:
>> 
>>> From: Chris Healy <healych@amazon.com>
>>>
>>> The Meson G12A Internal PHY does not support standard IEEE MMD extended
>>> register access, therefore add generic dummy stubs to fail the read and
>>> write MMD calls. This is necessary to prevent the core PHY code from
>>> erroneously believing that EEE is supported by this PHY even though this
>>> PHY does not support EEE, as MMD register access returns all FFFFs.
>> 
>> This is definitely something that should be done, Thx !
>> 
>>>
>>> Fixes: 5c3407abb338 ("net: phy: meson-gxl: add g12a support")
>> 
>> This commit does not seems appropriate, especially since only the GXL ops
>> are changed, not the g12a variant.
>> 
> The diff is a little bit misleading. The patch affects the G12A PHY.
>
>> This brings a 2nd point, any reason for not changing the g12 variant ?
>> I'm fairly confident it does support EEE either.
>> 
> Supposedly it's a typo and you mean "doesn't". Neither Chris nor me

Indeed ;)

> have GXL HW and we didn't want to submit a patch just based on speculation.
>

Ah - Ok.
I've tested something similar recently while working on the PHY.
I confirm that both GXL and G12a should stub those calls.

... maybe in separate patches to help stable backports.

Do you want to handle this or should I ?

>>> Reviewed-by: Heiner Kallweit <hkallweit1@gmail.com>
>>> Signed-off-by: Chris Healy <healych@amazon.com>
>>>

Reviewed-by: Jerome Brunet <jbrunet@baylibre.com>

>>> ---
>>>
>>> Changes in v3:
>>> * Add reviewed-by
>>> Change in v2:
>>> * Add fixes tag
>>>
>>>  drivers/net/phy/meson-gxl.c | 2 ++
>>>  1 file changed, 2 insertions(+)
>>>
>>> diff --git a/drivers/net/phy/meson-gxl.c b/drivers/net/phy/meson-gxl.c
>>> index c49062ad72c6..5e41658b1e2f 100644
>>> --- a/drivers/net/phy/meson-gxl.c
>>> +++ b/drivers/net/phy/meson-gxl.c
>>> @@ -271,6 +271,8 @@ static struct phy_driver meson_gxl_phy[] = {
>>>  		.handle_interrupt = meson_gxl_handle_interrupt,
>>>  		.suspend        = genphy_suspend,
>>>  		.resume         = genphy_resume,
>>> +		.read_mmd	= genphy_read_mmd_unsupported,
>>> +		.write_mmd	= genphy_write_mmd_unsupported,
>>>  	},
>>>  };
>> 

Re: [PATCH v3] net: phy: meson-gxl: Add generic dummy stubs for MMD register access

[Heiner Kallweit]

On 31.01.2023 11:59, Jerome Brunet wrote:
> 
> On Tue 31 Jan 2023 at 11:38, Heiner Kallweit <hkallweit1@gmail.com> wrote:
> 
>> On 31.01.2023 11:05, Jerome Brunet wrote:
>>>
>>> On Mon 30 Jan 2023 at 15:14, Chris Healy <cphealy@gmail.com> wrote:
>>>
>>>> From: Chris Healy <healych@amazon.com>
>>>>
>>>> The Meson G12A Internal PHY does not support standard IEEE MMD extended
>>>> register access, therefore add generic dummy stubs to fail the read and
>>>> write MMD calls. This is necessary to prevent the core PHY code from
>>>> erroneously believing that EEE is supported by this PHY even though this
>>>> PHY does not support EEE, as MMD register access returns all FFFFs.
>>>
>>> This is definitely something that should be done, Thx !
>>>
>>>>
>>>> Fixes: 5c3407abb338 ("net: phy: meson-gxl: add g12a support")
>>>
>>> This commit does not seems appropriate, especially since only the GXL ops
>>> are changed, not the g12a variant.
>>>
>> The diff is a little bit misleading. The patch affects the G12A PHY.
>>
>>> This brings a 2nd point, any reason for not changing the g12 variant ?
>>> I'm fairly confident it does support EEE either.
>>>
>> Supposedly it's a typo and you mean "doesn't". Neither Chris nor me
> 
> Indeed ;)
> 
>> have GXL HW and we didn't want to submit a patch just based on speculation.
>>
> 
> Ah - Ok.
> I've tested something similar recently while working on the PHY.
> I confirm that both GXL and G12a should stub those calls.
> 
> ... maybe in separate patches to help stable backports.
> 
> Do you want to handle this or should I ?
> 
I can take it, will add your Suggested-by.

>>>> Reviewed-by: Heiner Kallweit <hkallweit1@gmail.com>
>>>> Signed-off-by: Chris Healy <healych@amazon.com>
>>>>
> 
> Reviewed-by: Jerome Brunet <jbrunet@baylibre.com>
> 
>>>> ---
>>>>
>>>> Changes in v3:
>>>> * Add reviewed-by
>>>> Change in v2:
>>>> * Add fixes tag
>>>>
>>>>  drivers/net/phy/meson-gxl.c | 2 ++
>>>>  1 file changed, 2 insertions(+)
>>>>
>>>> diff --git a/drivers/net/phy/meson-gxl.c b/drivers/net/phy/meson-gxl.c
>>>> index c49062ad72c6..5e41658b1e2f 100644
>>>> --- a/drivers/net/phy/meson-gxl.c
>>>> +++ b/drivers/net/phy/meson-gxl.c
>>>> @@ -271,6 +271,8 @@ static struct phy_driver meson_gxl_phy[] = {
>>>>  		.handle_interrupt = meson_gxl_handle_interrupt,
>>>>  		.suspend        = genphy_suspend,
>>>>  		.resume         = genphy_resume,
>>>> +		.read_mmd	= genphy_read_mmd_unsupported,
>>>> +		.write_mmd	= genphy_write_mmd_unsupported,
>>>>  	},
>>>>  };
>>>
> 

Re: [PATCH v3] net: phy: meson-gxl: Add generic dummy stubs for MMD register access

[patchwork-bot+netdevbpf]

Hello:

This patch was applied to netdev/net.git (master)
by Jakub Kicinski <kuba@kernel.org>:

On Mon, 30 Jan 2023 15:14:02 -0800 you wrote:
> From: Chris Healy <healych@amazon.com>
> 
> The Meson G12A Internal PHY does not support standard IEEE MMD extended
> register access, therefore add generic dummy stubs to fail the read and
> write MMD calls. This is necessary to prevent the core PHY code from
> erroneously believing that EEE is supported by this PHY even though this
> PHY does not support EEE, as MMD register access returns all FFFFs.
> 
> [...]

Here is the summary with links:
  - [v3] net: phy: meson-gxl: Add generic dummy stubs for MMD register access
    https://git.kernel.org/netdev/net/c/afc2336f89dc

You are awesome, thank you!
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