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From: thunder.leizhen@huawei•com (leizhen)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH RFC v1 1/2] documentation/iommu: Add description of Hisilicon System MMU binding
Date: Tue, 17 Jun 2014 15:57:28 +0800	[thread overview]
Message-ID: <539FF4E8.7010202@huawei.com> (raw)
In-Reply-To: <5537408.I9tiuCA96J@wuerfel>

On 2014/6/17 0:42, Arnd Bergmann wrote:
> On Monday 16 June 2014 17:26:53 Will Deacon wrote:
>> On Fri, Jun 06, 2014 at 12:07:11PM +0100, Dave Martin wrote:
>>> On Fri, Jun 06, 2014 at 08:48:26AM +0200, Arnd Bergmann wrote:
>>>> On Thursday 05 June 2014 21:37:09 Zhen Lei wrote:
>>>>
>>>>> +- smmu-masters  : A list of phandles to device nodes representing bus
>>>>> +                  masters for which the SMMU can provide a translation
>>>>> +                  and their corresponding StreamIDs (see example below).
>>>>>
>>>>
>>>> We're currently in the process of defining a generic binding for IOMMUs.
>>>>
>>>> While the smmu-masters property was copied from an existing binding,
>>>> I think we will end up migrating away from that towards a common way
>>>> to express those things, and we shouldn't add another one doing this
>>>> in a nonstandard way. Please have a look at the latest discussion
>>>> about the iommu binding using #iommu-cells and a reference from the
>>>> master to the iommu and see if you can migrate your code to use that.
>>>
>>> Thanks for making this point -- I was going to do so yesterday but then
>>> hesitated due to uncertainty about whether this should really be a new
>>> driver.
>>>
>>> Either way, it would be very valuable at least to attempt to describe
>>> the Hisilicon SMMU implemenation using the new proposals, since that is
>>> a good test of how reusable the proposed generic binding actually is.
>>
>> If this ends up being an addition to the existing ARM SMMU driver, I'm
>> really not keen on using the new DT bindings. We're already stuck with
>> the old bindings for that driver -- supporting both old and new in the
>> same code only buys us maintenance headaches and pointless divergence
>> within the driver.
> 
> We have to migrate the driver to the new binding anyway, it may be
> a bit painful, but there are not really any users yet so there
> is a chance we can remove the nonstandard code at some point,
> perhaps in a few years.
> 
> 	Arnd
> 
> .
> 
My driver will base on arm-smmu, and I saw Will Deacon had agreed to you.
So me too.

  parent reply	other threads:[~2014-06-17  7:57 UTC|newest]

Thread overview: 24+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-06-05 13:37 [PATCH RFC v1 0/2] Add support for Hisilicon SMMU architecture Zhen Lei
2014-06-05 13:37 ` [PATCH RFC v1 1/2] documentation/iommu: Add description of Hisilicon System MMU binding Zhen Lei
2014-06-05 15:26   ` Mark Rutland
2014-06-06  6:48   ` Arnd Bergmann
2014-06-06 11:07     ` Dave Martin
2014-06-11  8:12       ` leizhen
2014-06-16 16:26       ` Will Deacon
2014-06-16 16:42         ` Arnd Bergmann
2014-06-16 16:45           ` Will Deacon
2014-06-16 17:25             ` Arnd Bergmann
2014-06-16 18:26               ` Will Deacon
2014-06-17  7:14                 ` Arnd Bergmann
2014-06-17 11:49                   ` Thierry Reding
2014-06-18 11:10                 ` Varun Sethi
2014-06-18 12:31                   ` Will Deacon
2014-06-20  9:54                     ` Varun Sethi
2014-06-20 17:49                       ` Will Deacon
2014-06-20 18:57                         ` Varun Sethi
2014-06-24 14:30                           ` Will Deacon
2014-06-17  7:57           ` leizhen [this message]
2014-06-16 16:44     ` Arnd Bergmann
2014-06-05 13:37 ` [PATCH RFC v1 2/2] iommu/hisilicon: Add support for Hisilicon Ltd. System MMU architecture Zhen Lei
2014-06-05 15:21 ` [PATCH RFC v1 0/2] Add support for Hisilicon SMMU architecture Mark Rutland
2014-06-06  0:21   ` leizhen

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