linux-kernel - Re: [RFC v4 2/5] usb: dwc3: core: Refactor PHY logic to support Multiport Controller

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <20230125222751.qfaikiiwr2m73ihu@synopsys.com>
Date:   Wed, 25 Jan 2023 22:27:51 +0000
From:   Thinh Nguyen <Thinh.Nguyen@...opsys.com>
To:     Jack Pham <quic_jackp@...cinc.com>
CC:     Thinh Nguyen <Thinh.Nguyen@...opsys.com>,
        Krishna Kurapati PSSNV <quic_kriskura@...cinc.com>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        Philipp Zabel <p.zabel@...gutronix.de>,
        Andy Gross <agross@...nel.org>,
        Bjorn Andersson <andersson@...nel.org>,
        Konrad Dybcio <konrad.dybcio@...aro.org>,
        Rob Herring <robh+dt@...nel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@...aro.org>,
        Felipe Balbi <balbi@...nel.org>,
        "linux-usb@...r.kernel.org" <linux-usb@...r.kernel.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        "linux-arm-msm@...r.kernel.org" <linux-arm-msm@...r.kernel.org>,
        "devicetree@...r.kernel.org" <devicetree@...r.kernel.org>,
        Pavan Kondeti <quic_pkondeti@...cinc.com>,
        Pratham Pratap <quic_ppratap@...cinc.com>,
        Harsh Agarwal <quic_harshq@...cinc.com>,
        Wesley Cheng <quic_wcheng@...cinc.com>,
        "quic_shazhuss@...cinc.com" <quic_shazhuss@...cinc.com>
Subject: Re: [RFC v4 2/5] usb: dwc3: core: Refactor PHY logic to support
 Multiport Controller

On Wed, Jan 25, 2023, Jack Pham wrote:
> On Wed, Jan 25, 2023 at 07:08:10PM +0000, Thinh Nguyen wrote:
> 
> <snip>
> 
> > > +       /*
> > > +        * If the controller is not host-only, then it must be a
> > > +        * single port controller.
> > > +        */
> 
> Thinh, is this a correct assumption?  Is it possible for the IP to be
> synthesized to support both dual-role and multiple ports?  We know that
> when operating in device mode only the first port can be used but the
> additional ports would be usable when in host.
> 

Yes. Maybe we should rephrase it a bit. Perhaps something like this:
"Currently, only host mode supports multi-port"

In case this may change in the future.

BR,
Thinh


> 
> > > +       temp = readl(regs + DWC3_GHWPARAMS0);
> > > +       hw_mode = DWC3_GHWPARAMS0_MODE(temp);
> > > +       if (hw_mode != DWC3_GHWPARAMS0_MODE_HOST) {
> > > +               dwc->num_ports = 1;
> > > +               dwc->num_ss_ports = 1;
> > > +               return 0;
> > > +       }
> > 
> > This check should be done before we get into this function.