From: David Brownell <david-b@pacbell.net>
To: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Cc: leoli@freescale.com, greg@kroah.com, linux-usb@vger.kernel.org,
linux-kernel@vger.kernel.org, linuxppc-dev@ozlabs.org,
Andrew Morton <akpm@linux-foundation.org>,
timur@freescale.com
Subject: Re: [PATCH 3/3] USB: driver for Freescale QUICC Engine USB Host Controller
Date: Wed, 24 Sep 2008 11:59:03 -0700 [thread overview]
Message-ID: <200809241159.04427.david-b@pacbell.net> (raw)
In-Reply-To: <48DA1544.5010307@ru.mvista.com>
On Wednesday 24 September 2008, Sergei Shtylyov wrote:
>
> >> ... then the root hub emulation is completely pointless.
> >>
> >
> > It isn't. We always should emulate the root hub. The root hub
> > is part and parcel of any USB Host. Even the one-port one.
>
> Hm, maybe that's what USB core thinks (because UHCI/OHCI/EHCI all
> have it) but e.g. MUSB doesn't have the root hub registers...
Only the OHCI registers have bit positions matching what the USB
spec says for hub status bits. Everything else, including musb_hdrc,
has the relevant status encoded in other bits.
> I looked at the core and figured that USB core seems to use the root hub
> interface for port PM, etc. and expects it to bee present, so it seems
> unavoidable indeed... :-/
Or more fundamentally: for enumeration. "Unavoidable" is correct. ;)
next prev parent reply other threads:[~2008-09-24 18:59 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-09-18 15:16 [PATCH 0/3] Patches to support QE USB Host Controller Anton Vorontsov
2008-09-18 15:17 ` [PATCH 1/3] gpiolib: make gpio_to_chip() public Anton Vorontsov
2008-09-18 15:17 ` [PATCH 2/3] powerpc/qe: new call to revert a gpio to a dedicated function Anton Vorontsov
2008-09-18 15:17 ` [PATCH 3/3] USB: driver for Freescale QUICC Engine USB Host Controller Anton Vorontsov
2008-09-19 23:23 ` Andrew Morton
2008-09-23 18:31 ` Anton Vorontsov
2008-09-23 18:32 ` [PATCH 1/2] USB: Protect hcd.h from multiple inclusions Anton Vorontsov
2008-09-23 18:32 ` [PATCH 2/2] USB: driver for Freescale QUICC Engine USB Host Controller Anton Vorontsov
2008-09-23 21:32 ` [PATCH 3/3] " Sergei Shtylyov
2008-09-23 21:35 ` Sergei Shtylyov
2008-09-23 22:57 ` Anton Vorontsov
2008-09-24 10:24 ` Sergei Shtylyov
2008-09-24 10:48 ` Sergei Shtylyov
2008-09-24 18:59 ` David Brownell [this message]
2008-09-24 19:17 ` Sergei Shtylyov
-- strict thread matches above, loose matches on Subject: below --
2008-08-08 16:17 [PATCH 0/3] Patches to support QE " Anton Vorontsov
2008-08-08 16:18 ` [PATCH 3/3] USB: driver for Freescale QUICC Engine " Anton Vorontsov
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=200809241159.04427.david-b@pacbell.net \
--to=david-b@pacbell.net \
--cc=akpm@linux-foundation.org \
--cc=greg@kroah.com \
--cc=leoli@freescale.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-usb@vger.kernel.org \
--cc=linuxppc-dev@ozlabs.org \
--cc=sshtylyov@ru.mvista.com \
--cc=timur@freescale.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).