From: Matt Sealey <matt@genesi-usa•com>
To: Valentine Barshak <vbarshak@ru•mvista.com>
Cc: David Brownell <david-b@pacbell•net>,
linux-usb-devel@lists•sourceforge.net, linuxppc-dev@ozlabs•org
Subject: Re: [linux-usb-devel] [PATCH 1/2] USB: Rework OHCI PPC OF for new bindings
Date: Thu, 25 Oct 2007 19:14:48 +0100 [thread overview]
Message-ID: <4720DD18.9000603@genesi-usa.com> (raw)
In-Reply-To: <4720CE3E.5030204@ru.mvista.com>
Valentine,
Please do the very minimal required to keep supporting the Efika.
As for an little endian OHCI controller on an OF bus, I would not
consider it an impossibility. But, not having the big-endian
property fixes this; OHCI is little-endian by default. You need
only report "difference" in device trees, overzealous naming of
a billion kinds of 99.99999% compatible controllers is just a
waste of space.
I prefer the new binding to a degree. I like the big-endian property
and I like the reporting of a standard controller type (usb-ohci
rather than building in chip names). However by making the driver
support only the recommending binding, we break old platforms for
the sake of making new ones cleaner.
I wish someone would have sat down and defined the 5200 device
tree in a design committee rather than a peer review post-commit
system. In fact, that is a great idea, we can start this off with
the MPC5121E right now, and get the damn thing RIGHT.
--
Matt Sealey <matt@genesi-usa•com>
Genesi, Manager, Developer Relations
Valentine Barshak wrote:
> Grant Likely wrote:
>> On 10/25/07, Valentine Barshak <vbarshak@ru•mvista.com> wrote:
>>> Grant Likely wrote:
>>>> On 10/24/07, David Brownell <david-b@pacbell•net> wrote:
>>>>> On Wednesday 24 October 2007, Matt Sealey wrote:
>>>>>> Can we just make sure real quickly that the changing of compatibles
>>>>>> doesn't break existing, not-easily-flashable firmwares?
>>>>> Yeah, I'm not keen on such breakage either...
>>>> Add my voice to the chorus. It's okay to change the binding, but make
>>>> sure the old binding is still supported.
>>>>
>>>> Cheers,
>>>> g.
>>>>
>>> Actually, I thought that changing the DTS stuff for mpc52xx boards would
>>> suffice. Sorry, I was unaware of Efika firmware here. I'll keep old
>>> bindings as well.
>>
>> Even if that were the case; I'm nervous about breaking compatibility
>> with old device trees.
>
> If we keep the old bindings intact in the driver code then the old dts
> files should work fine. But I'm starting to doubt we really need any new
> bindings for this if we still have to keep the old ones.
> BTW, does anybody know of any ohci-le devices on OF bus?
> Thanks,
> Valentine.
>
>>
>> We probably need a formal guideline here. ie. When is it okay to drop
>> compatibility with old dts files?
>>
>>> Does the device tree have "ohci-bigendian" or "ohci-be" compatible
>>> property on Efika?
>>
>> If it doesn't, it can be added during prom_init.c We're already doing
>> a bunch of efika fixups there anyway.
>>
>> Cheers,
>> g.
>>
>
next prev parent reply other threads:[~2007-10-25 18:12 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-10-24 16:22 [PATCH 0/2] USB: Rework OHCI PPC OF driver to support new bindings Valentine Barshak
2007-10-24 16:34 ` [PATCH 1/2] USB: Rework OHCI PPC OF for " Valentine Barshak
2007-10-24 22:05 ` Matt Sealey
2007-10-25 1:50 ` [linux-usb-devel] " David Brownell
2007-10-25 2:41 ` Grant Likely
2007-10-25 11:48 ` Valentine Barshak
2007-10-25 14:21 ` Grant Likely
2007-10-25 17:11 ` Valentine Barshak
2007-10-25 18:14 ` Matt Sealey [this message]
2007-10-25 18:13 ` Valentine Barshak
2007-10-25 18:10 ` Matt Sealey
2007-10-25 18:01 ` Matt Sealey
2007-10-25 18:50 ` Valentine Barshak
2007-10-25 22:02 ` Matt Sealey
2007-10-26 11:24 ` Valentine Barshak
2007-10-26 12:13 ` Valentine Barshak
2007-11-01 11:19 ` tnt
2007-11-01 12:44 ` Valentine Barshak
2007-11-01 13:46 ` [linux-usb-devel] " Dale Farnsworth
2007-10-24 16:35 ` [PATCH 2/2] PowerPC: Update USB OHCI DTS entires " Valentine Barshak
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