linux-kernel - Re: [RFC PATCH] USB:XHCI:Modify XHCI driver for USB2.0 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: <cd4f7d23-0c21-5ea8-3224-cde1256a36a0@huawei.com>
Date:   Thu, 4 Mar 2021 12:08:43 +0800
From:   liulongfang <liulongfang@...wei.com>
To:     Peter Chen <peter.chen@...nel.org>
CC:     Greg KH <gregkh@...uxfoundation.org>, <mathias.nyman@...el.com>,
        <linux-usb@...r.kernel.org>, <yisen.zhuang@...wei.com>,
        <linux-kernel@...r.kernel.org>
Subject: Re: [RFC PATCH] USB:XHCI:Modify XHCI driver for USB2.0 controller

On 2021/3/4 9:35, Peter Chen wrote:
> On 21-02-27 11:31:00, liulongfang wrote:
>> On 2021/2/26 16:38, Greg KH wrote:
>>> On Fri, Feb 26, 2021 at 04:21:37PM +0800, Longfang Liu wrote:
>>>> Our current XHCI hardware controller has been customized to only
>>>> support USB 2.0 ports.
>>>
>>> That sounds like a spec violation, right?  Why do you want to do this?
>>>
>>> greg k-h
>>> .
>>>
>> I hope to support a USB2.0-only mode on the XHCI controller
>> through software configuration.
>> Thanks.
> 
> If your hardware has disabled USB3 logic, when the USB3 device is plugged,
> since there are no RX signal on the bus, the device will not enable USB3
> logic, and only USB2 signals will be on the bus, there are only USB devices on
> USB2 roothub later. So, any issues you have met?
> 
I don’t want to see the USB3 bus controller in the system,
but it actually exists.
Thanks.
Longfang, Liu