From: Sergei Shtylyov <sshtylyov@ru.mvista.com>
To: avorontsov@ru.mvista.com
Cc: Andrew Morton <akpm@linux-foundation.org>,
dbrownell@users.sourceforge.net, greg@kroah.com,
linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org,
linuxppc-dev@ozlabs.org, leoli@freescale.com,
timur@freescale.com
Subject: Re: [PATCH 3/3] USB: driver for Freescale QUICC Engine USB Host Controller
Date: Wed, 24 Sep 2008 14:24:04 +0400 [thread overview]
Message-ID: <48DA1544.5010307@ru.mvista.com> (raw)
In-Reply-To: <20080923225730.GB13617@oksana.dev.rtsoft.ru>
Hello.
Anton Vorontsov wrote:
>>>>>> This controller does not integrate the root hub, so this driver also
>>>>>> fakes one-port hub. External hub is required to support more than
>>>>>> one device.
>>>>>>
>>>>>> ...
>>>>>>
>>>>>>
>>>>>>
>>>>> Please, no.
>>>>>
>>>>>
>>>> What exactly 'no'? ;-)
>>>>
>>>>
>>> No one-port hubs I guess -- they are pointless. Though e.g. MUSB
>>> driver creates one -- I guess to impersonate a transaction translating
>>> high-speed hub...
>>>
>>>
>> ... 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...
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... :-/
WBR, Sergei
next prev parent reply other threads:[~2008-09-24 10:24 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 [this message]
2008-09-24 10:48 ` Sergei Shtylyov
2008-09-24 18:59 ` David Brownell
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
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