Re: [PATCH net-next v4 1/7] dt-bindings: net: ftgmac100: Make Aspeed compatibles standalone

[Conor Dooley <conor@kernel.org>]

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On Tue, Oct 20, 2026 at 01:14:41PM -0500, Rob Herring wrote:
> On Tue, Oct 20, 2026 at 07:34:12PM +0800, Jacky Chou wrote:
> > The aspeed,ast2400-mac, aspeed,ast2500-mac, and aspeed,ast2600-mac
> > compatibles are currently only valid when paired with the generic
> > "faraday,ftgmac100" fallback: if a node ever bound through the
> > generic entry alone, ftgmac100_probe() would set
> > rxdes0_edorr_mask/txdes0_edotr_mask to BIT(15) instead of the Aspeed
> > BIT(30), skip Aspeed clock setup, and leave the DMA mask too narrow.
> > 
> > Make each of them a standalone compatible instead, so none of the
> > Aspeed compatibles require the generic fallback alongside them.
> > 
> > Signed-off-by: Jacky Chou <jacky_chou@aspeedtech.com>
> > 
> > ---
> > ftgmac100_of_match[] has had dedicated entries for AST2400, AST2500,
> > and AST2600 since commit 03a2aba50b2c ("net: ftgmac100: List all
> > compatibles"), so there is no known kernel + devicetree combination
> > where a node has actually bound through the generic entry and gotten
> > the wrong EDORR bit. This part is a binding correctness fix, not a fix
> > for an observed failure.
> > 
> > Note that arch/arm/boot/dts/aspeed/aspeed-g4.dtsi, aspeed-g5.dtsi, and
> > aspeed-g6.dtsi still declare their MAC nodes with the two-string
> > "aspeed,astXXXX-mac", "faraday,ftgmac100" compatible, so this will make
> > dtbs_check warn against those files until the redundant fallback
> > compatible is dropped there as well. That .dtsi change will be sent as
> > a separate series through the Aspeed/arm-soc tree, since dt-bindings
> > changes don't go through that tree.
> 
> No. This just creates unnecessary warnings even if only temporary.
> 
> What a driver uses doesn't matter. That can evolve over time, but that 
> doesn't mean we change the DT schema.

The reason I suggested changing this is because the device used as a
fallback compatible is apparently not actually compatible at all and
were it to be used the device would malfunction.
The original code (from 2016) only worked because it checked the machine
compatible and slightly later on matched on the ftgmac compatible but
then explicitly checked for "ast2400-mac" etc using
of_device_is_compatible().

If you don't want the current stuff deleted, then at the very least it
should be marked deprecated and the standalone aspeed compatible stuff
added alongside it.

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