Re: [PATCH v6 13/33] dt-bindings: usb: dwc3: Add snps,num-hc-interrupters definition

From: Wesley Cheng
Date: Mon Sep 18 2023 - 20:25:38 EST


Hi Rob,

On 9/18/2023 1:19 PM, Rob Herring wrote:
On Fri, Sep 15, 2023 at 05:43:45PM -0700, Wesley Cheng wrote:
Hi Konrad,

On 9/15/2023 5:35 PM, Konrad Dybcio wrote:
On 16.09.2023 02:10, Wesley Cheng wrote:
Add a new definition for specifying how many XHCI secondary interrupters
can be allocated. XHCI in general can potentially support up to 1024
interrupters, which some uses may want to limit depending on how many
users utilize the interrupters.

Signed-off-by: Wesley Cheng <quic_wcheng@xxxxxxxxxxx>
---
Any reason for a DWC3-specific property? Why not just
use the XHCI-common one from patch 14 and error out if
a value of more than 8 is found?


I'm pretty sure I said use the common one already...


Yes, you mentioned that in the last rev.


Not every XHCI plat user is going to be DWC3. In case DWC3 is used, the
DWC3 host driver is the one that populates and adds the XHCI plat device (no
separate device node for XHCI), so that requires the DWC3 host to also
populate properties for the XHCI device. (dwc3_host_init())

This binding references usb-xhci.yaml already, so any property from
there is allowed. Linux needs to handle that regardless of what the
driver structure/division looks like.


Ok, understood. I will remove the need to have another DWC3 property and just use the XHCI one directly. Checks are already in place in the DWC3 parser to limit the interrupters if it exceeds 8.

Thanks
Wesley Cheng