Re: [net-next v7 4/7] net: mtip: The L2 switch driver for imx287

[Krzysztof Kozlowski <krzk@kernel.org>]

On 25/04/2025 08:05, Lukasz Majewski wrote:
> Hi Krzysztof, Jakub,
> 
>> On 25/04/2025 03:11, Jakub Kicinski wrote:
>>> On Wed, 23 Apr 2025 09:29:08 +0200 Lukasz Majewski wrote:  
>>>> This patch series provides support for More Than IP L2 switch
>>>> embedded in the imx287 SoC.
>>>>
>>>> This is a two port switch (placed between uDMA[01] and
>>>> MAC-NET[01]), which can be used for offloading the network traffic.
>>>>
>>>> It can be used interchangeably with current FEC driver - to be more
>>>> specific: one can use either of it, depending on the requirements.
>>>>
>>>> The biggest difference is the usage of DMA - when FEC is used,
>>>> separate DMAs are available for each ENET-MAC block.
>>>> However, with switch enabled - only the DMA0 is used to
>>>> send/receive data to/form switch (and then switch sends them to
>>>> respecitive ports).  
>>>
>>> Lots of sparse warnings and build issues here, at least on x86.
>>>
>>> Could you make sure it's clean with an allmodconfig config, 
>>> something like:
>>>
>>> make C=1 W=1 drivers/net/ethernet/freescale/mtipsw/   
>>
>> ... and W=1 with clang as well.
>>
> 
> The sparse warnings are because of struct switch_t casting and register

clang W=1 fails on errors, so it is not only sparse:

error: cast to smaller integer type 'uint' (aka 'unsigned int') from
'struct cbd_t *' [-Werror,-Wpointer-to-int-cast]

You probably wanted there kenel_ulong_t.

> access with this paradigm (as it is done with other drivers).

I don't understand. I see code like:

	struct switch_t *fecp = fep->hwp;

But this is not a cast - the same types.
> 
> What is the advise here from the community?
> 
>> Best regards,
>> Krzysztof
> 
> 
> 
> 
> Best regards,
> 
> Lukasz Majewski
> 
> --
> 
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Best regards,
Krzysztof