Re: [PATCH v2 net 2/4] dt-bindings: net: Document fsl,erratum-a009885

[Tobias Waldekranz <tobias@waldekranz.com>]

On Thu, Jan 20, 2022 at 20:08, Rob Herring <robh@kernel.org> wrote:
> On Tue, Jan 18, 2022 at 10:50:51PM +0100, Tobias Waldekranz wrote:
>> Update FMan binding documentation with the newly added workaround for
>> erratum A-009885.
>> 
>> Signed-off-by: Tobias Waldekranz <tobias@waldekranz.com>
>> Reviewed-by: Andrew Lunn <andrew@lunn.ch>
>> ---
>>  Documentation/devicetree/bindings/net/fsl-fman.txt | 9 +++++++++
>>  1 file changed, 9 insertions(+)
>> 
>> diff --git a/Documentation/devicetree/bindings/net/fsl-fman.txt b/Documentation/devicetree/bindings/net/fsl-fman.txt
>> index c00fb0d22c7b..020337f3c05f 100644
>> --- a/Documentation/devicetree/bindings/net/fsl-fman.txt
>> +++ b/Documentation/devicetree/bindings/net/fsl-fman.txt
>> @@ -410,6 +410,15 @@ PROPERTIES
>>  		The settings and programming routines for internal/external
>>  		MDIO are different. Must be included for internal MDIO.
>>  
>> +- fsl,erratum-a009885
>
> Adding errata properties doesn't work because then you have to update 
> your dtb to fix the issue where as if you use the compatible property 
> (specific to the SoC) you can fix the issue with just a (stable) kernel 
> update.
>
> Yes, I see we already have some, but doesn't mean we need more of them.

I agree. Unfortunately all users of the driver also use the same
compatible string, so there was no way I could think of that would not
involve rebuilding DTBs anyway. Given that situation, I chose to just
extend what was already there.