Subject: Re: [PATCH v5 3/3] PCI: dwc: ep: Support BAR subrange inbound mapping via Address Match Mode iATU

From: Niklas Cassel <[email-masked]>
Date: Mon, 12 Jan 2026 12:43:50 +0100

Hello Koichiro,

On Sat, Jan 10, 2026 at 11:29:06PM +0900, Koichiro Den wrote:

(snip)

> > Your new feature (epc_features->subrange_mapping) in epc_features appears
> > to depend on epc_features->dynamic_inbound_mapping, so it is a shame that
> > we don't have a epc_features->dynamic_inbound_mapping bit, so that this new
> > feature could have depended on that bit.
> > 
> > 	if (epf_bar->use_submap &&
> > 	    !(epc_features->dynamic_inbound_mapping &&
> > 	      epc_features->subrange_mapping))
> > 		return -EINVAL;
> > 
> > 
> > I think adding some documentation is a good step.
> > 
> > Perhaps we should also introduce a epc_features->dynamic_inbound_mapping bit?
> > Since you are making DWC glue drivers return a mutable EPC features, we could
> > set this bit in the DWC driver after that commit. What do you think?
> 
> As you pointed out, support for dynamic_inbound_mapping is needed
> independently of my series. Given that, it would make sense to handle it
> either before this series, or to fold it into the next iteration (=v6) of
> the series if that is preferred.

Please fold it into the next iteration (=v6).

It should be a one liner patch in the DWC driver, at least if you put it
after your "PCI: dwc: Allow glue drivers to return mutable EPC features"
patch.

Thank you for all your efforts on improving the endpoint framework.

Kind regards,
Niklas