From: liulongfang <liulongfang@huawei.com>
To: Peter Chen <peter.chen@kernel.org>
Cc: Greg KH <gregkh@linuxfoundation.org>, <mathias.nyman@intel.com>,
<linux-usb@vger.kernel.org>, <yisen.zhuang@huawei.com>,
<linux-kernel@vger.kernel.org>
Subject: Re: [RFC PATCH] USB:XHCI:Modify XHCI driver for USB2.0 controller
Date: Thu, 4 Mar 2021 12:08:43 +0800 [thread overview]
Message-ID: <cd4f7d23-0c21-5ea8-3224-cde1256a36a0@huawei.com> (raw)
In-Reply-To: <20210304013548.GA16596@nchen>
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
next prev parent reply other threads:[~2021-03-04 4:10 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-02-26 8:21 Longfang Liu
2021-02-26 8:38 ` Greg KH
2021-02-27 3:31 ` liulongfang
2021-03-04 1:35 ` Peter Chen
2021-03-04 4:08 ` liulongfang [this message]
2021-02-26 9:22 ` Mathias Nyman
2021-02-27 3:34 ` liulongfang
2021-02-26 16:30 ` Alan Stern
2021-02-27 3:38 ` liulongfang
2021-02-27 3:48 ` liulongfang
2021-02-27 16:27 ` Alan Stern
2021-03-01 1:58 ` liulongfang
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=cd4f7d23-0c21-5ea8-3224-cde1256a36a0@huawei.com \
--to=liulongfang@huawei.com \
--cc=gregkh@linuxfoundation.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-usb@vger.kernel.org \
--cc=mathias.nyman@intel.com \
--cc=peter.chen@kernel.org \
--cc=yisen.zhuang@huawei.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox
all inboxes | Powered by JetHome®