Re: [PATCH net-next 2/2] net: stmmac: dwmac4: Use the full perfect filter ability for UC filter

[Andrew Lunn]

On Tue, Sep 01, 2026 at 08:37:20AM +0200, Maxime Chevallier wrote:
> Hi,
> 
> On 9/1/26 02:12, Andrew Lunn wrote:
> > On Mon, Aug 31, 2026 at 09:01:20AM +0200, Maxime Chevallier wrote:
> >> Contrary to dwmac1000 that gets its number of perfect filter entries
> >> through the 'snps,perfect-filter-entries' property, dwmac4 allows
> >> reading the filter size from the HW features registers.
> > 
> > Does dwmac4 take any notice of "snps,perfect-filter-entries"? Should
> > it be marked deprecated?
> 
> It's only used on :
> 
>   "st,spear600-gmac"
>   "snps,dwmac-3.50a"
>   "snps,dwmac-3.70a"
>   "snps,dwmac-3.72a"
>   "snps,dwmac"
> 
> So, dwmac1000.
> 
> I'd say, we can definitely deprecate on IPs that don't match these.
> 
> Interestingly, there are _some_ dwmac4 devicetrees out there that use
> this property. It achieves nothing, and even worse, doesn't match what
> the HW reports :
> 
> In arch/riscv/boot/dts/starfive/jh7110.dtsi for example :
> 
> gmac1: ethernet@16040000 {                                            
> 	compatible = "starfive,jh7110-dwmac", "snps,dwmac-5.20";
> 	[...]
> 	snps,perfect-filter-entries = <256>;
> }

So another thing for the TODO list, extend the YAML description to
make properties conditional on the IP core version, so the validator
tools will pick this up.

	Andrew