linux-usb.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Alan Stern <stern@rowland.harvard.edu>
To: Ikjoon Jang <ikjn@chromium.org>
Cc: linux-usb@vger.kernel.org, <devicetree@vger.kernel.org>,
	<linux-kernel@vger.kernel.org>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Rob Herring <robh+dt@kernel.org>,
	Mark Rutland <mark.rutland@arm.com>,
	Suwan Kim <suwan.kim027@gmail.com>,
	"Gustavo A . R . Silva" <gustavo@embeddedor.com>,
	Johan Hovold <johan@kernel.org>,
	Nicolas Boitchat <drinkcat@chromium.org>
Subject: Re: [PATCH 0/2] usb: override hub device bInterval with device node
Date: Sun, 17 Nov 2019 10:46:19 -0500 (EST)	[thread overview]
Message-ID: <Pine.LNX.4.44L0.1911171043060.7716-100000@netrider.rowland.org> (raw)
In-Reply-To: <20191117033149.259303-1-ikjn@chromium.org>

On Sun, 17 Nov 2019, Ikjoon Jang wrote:

> This patchset enables hard wired hub device to use different bInterval
> from its descriptor when the hub has a combined device node.
> 
> When we know the specific hard wired hub supports changing its polling
> interval, we can adjust hub's interval to reduce the time of waking up
> from autosuspend or connect detection of HIDs.

In fact, _all_ hubs support changing the polling interval.  The value 
given in the USB spec is just an upper limit; any smaller value is 
equally acceptable.

So why are you doing this only for hard-wired hubs?  Why not for all 
hubs?

And is 250 ms really too long to wait for remote wakeup or connect 
detection?  What's the real motivation behind this change?

Alan Stern


  parent reply	other threads:[~2019-11-17 15:46 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-11-17  3:31 [PATCH 0/2] usb: override hub device bInterval with device node Ikjoon Jang
2019-11-17  7:14 ` Greg Kroah-Hartman
2019-11-19  4:05   ` Ikjoon Jang
2019-11-17 15:46 ` Alan Stern [this message]
2019-11-19  5:18   ` Ikjoon Jang
2019-11-19 15:14     ` Alan Stern
2019-11-20  7:22       ` Ikjoon Jang
2019-11-20 16:19         ` Alan Stern

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=Pine.LNX.4.44L0.1911171043060.7716-100000@netrider.rowland.org \
    --to=stern@rowland.harvard.edu \
    --cc=devicetree@vger.kernel.org \
    --cc=drinkcat@chromium.org \
    --cc=gregkh@linuxfoundation.org \
    --cc=gustavo@embeddedor.com \
    --cc=ikjn@chromium.org \
    --cc=johan@kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-usb@vger.kernel.org \
    --cc=mark.rutland@arm.com \
    --cc=robh+dt@kernel.org \
    --cc=suwan.kim027@gmail.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;
as well as URLs for NNTP newsgroup(s).