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Date:   Fri, 10 May 2019 17:53:35 +0200
From:   Christoph Hellwig <hch@lst.de>
To:     Robin Murphy <robin.murphy@arm.com>
Cc:     laurentiu.tudor@nxp.com, hch@lst.de, stern@rowland.harvard.edu,
        gregkh@linuxfoundation.org, linux-usb@vger.kernel.org,
        marex@denx.de, leoyang.li@nxp.com, linux-kernel@vger.kernel.org
Subject: Re: [RFC PATCH 0/3] prerequisites for device reserved local mem
 rework
Message-ID: <20190510155335.GA32010@lst.de>
References: <20190510145646.10078-1-laurentiu.tudor@nxp.com> <e6410453-9ca3-4bdc-3c74-654333f2806f@arm.com>
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On Fri, May 10, 2019 at 04:03:37PM +0100, Robin Murphy wrote:
> Hi Laurentiu,
>
> On 10/05/2019 15:56,  wrote:
>> From: Laurentiu Tudor <laurentiu.tudor@nxp.com>
>>
>> For HCs that have local memory, replace the current DMA API usage
>> with a genalloc generic allocator to manage the mappings for these
>> devices.
>> This is in preparation for dropping the existing "coherent" dma
>> mem declaration APIs. Current implementation was relying on a short
>> circuit in the DMA API that in the end, was acting as an allocator
>> for these type of devices.
>>
>> Only compiled tested, so any volunteers willing to test are most welcome.
>
> Based on my diggings into this in the past, I would expect that you need to 
> do something about hcd_alloc_coherent() as well.

Yep.  And it might make sense to share the code for that and the
ohci internal allocations with a helper.