Re: [PATCH] arm64: dts: zynqmp: Add xlnx prefix to GEM compatible string

[Krzysztof Kozlowski]

On 09/12/2022 16:23, Michal Simek wrote:
> 
> 
> On 12/9/22 16:11, Krzysztof Kozlowski wrote:
>> On 09/12/2022 14:56, Michal Simek wrote:
>>> From: Harini Katakam <harini.katakam@xxxxxxx>
>>>
>>> cdns,zynq/zynqmp/versal-gem was recently deprecated in Linux in
>>> favour of xlnx prefix. Add this new compatible string and retain
>>> the existing string for compatibility with uboot drivers.
>>>
>>> Signed-off-by: Harini Katakam <harini.katakam@xxxxxxx>
>>> Signed-off-by: Michal Simek <michal.simek@xxxxxxx>
>>> ---
>>>
>>>   arch/arm64/boot/dts/xilinx/zynqmp.dtsi | 8 ++++----
>>>   1 file changed, 4 insertions(+), 4 deletions(-)
>>>
>>> diff --git a/arch/arm64/boot/dts/xilinx/zynqmp.dtsi b/arch/arm64/boot/dts/xilinx/zynqmp.dtsi
>>> index 8553299f12eb..233127d94204 100644
>>> --- a/arch/arm64/boot/dts/xilinx/zynqmp.dtsi
>>> +++ b/arch/arm64/boot/dts/xilinx/zynqmp.dtsi
>>> @@ -507,7 +507,7 @@ nand0: nand-controller@ff100000 {
>>>   		};
>>>   
>>>   		gem0: ethernet@ff0b0000 {
>>> -			compatible = "cdns,zynqmp-gem", "cdns,gem";
>>> +			compatible = "xlnx,zynqmp-gem", "cdns,zynqmp-gem", "cdns,gem";
>>
>> That's not what the bindings are saying. If this was the intention of
>> AMD, you should have replied to my patch that you need prolonged
>> backwards compatibility.
> 
> I have sent the patch to U-Boot to support new compatible string and CC you on 
> that too.
> 
> I have no problem to do switch just to xlnx one but it is not fully accurate 
> that cdns,versal-gem wasn't used. True is not in Linux but it was used in U-Boot.
> 
> If we can go straight to xlnx,zynqmp-gem, cdns,gem I will send v2 of this patch.

Yeah, there might be also few other users of these bindings (other
systems), thus the DTS change might need to wait a bit. The other way
would be to change bindings to match your three-compatible usage, but
then we would have these in three places in DTS (old compatible,
new+old, only new).

Best regards,
Krzysztof