From: Ezequiel Garcia <ezequiel@collabora.com>
To: Christoph Hellwig <hch@infradead.org>
Cc: linux-media@vger.kernel.org, linux-usb@vger.kernel.org,
linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org,
Laurent Pinchart <laurent.pinchart@ideasonboard.com>,
Tomasz Figa <tfiga@chromium.org>,
"Matwey V . Kornilov" <matwey@sai.msu.ru>,
Alan Stern <stern@rowland.harvard.edu>,
kernel@collabora.com, Keiichi Watanabe <keiichiw@chromium.org>
Subject: Re: [RFC 2/3] USB: core: Add non-coherent buffer allocation helpers
Date: Thu, 30 Aug 2018 19:11:35 -0300 [thread overview]
Message-ID: <4fc5107f93871599ead017af7ad50f22535a7683.camel@collabora.com> (raw)
In-Reply-To: <20180830175850.GA11521@infradead.org>
On Thu, 2018-08-30 at 10:58 -0700, Christoph Hellwig wrote:
> Please don't introduce new DMA_ATTR_NON_CONSISTENT users, it is
> a rather horrible interface, and I plan to kill it off rather sooner
> than later. I plan to post some patches for a better interface
> that can reuse the normal dma_sync_single_* interfaces for ownership
> transfers. I can happily include usb in that initial patch set based
> on your work here if that helps.
Please do. Until we have proper allocators that go thru the DMA API,
drivers will have to kmalloc the USB transfer buffers, and have
streaming mappings. Which in turns mean not using IOMMU or CMA.
Regards,
Eze
WARNING: multiple messages have this Message-ID (diff)
From: Ezequiel Garcia <ezequiel@collabora.com>
To: Christoph Hellwig <hch@infradead.org>
Cc: linux-media@vger.kernel.org, linux-usb@vger.kernel.org,
linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org,
Laurent Pinchart <laurent.pinchart@ideasonboard.com>,
Tomasz Figa <tfiga@chromium.org>,
"Matwey V . Kornilov" <matwey@sai.msu.ru>,
Alan Stern <stern@rowland.harvard.edu>,
kernel@collabora.com, Keiichi Watanabe <keiichiw@chromium.org>
Subject: [RFC,2/3] USB: core: Add non-coherent buffer allocation helpers
Date: Thu, 30 Aug 2018 19:11:35 -0300 [thread overview]
Message-ID: <4fc5107f93871599ead017af7ad50f22535a7683.camel@collabora.com> (raw)
On Thu, 2018-08-30 at 10:58 -0700, Christoph Hellwig wrote:
> Please don't introduce new DMA_ATTR_NON_CONSISTENT users, it is
> a rather horrible interface, and I plan to kill it off rather sooner
> than later. I plan to post some patches for a better interface
> that can reuse the normal dma_sync_single_* interfaces for ownership
> transfers. I can happily include usb in that initial patch set based
> on your work here if that helps.
Please do. Until we have proper allocators that go thru the DMA API,
drivers will have to kmalloc the USB transfer buffers, and have
streaming mappings. Which in turns mean not using IOMMU or CMA.
Regards,
Eze
WARNING: multiple messages have this Message-ID (diff)
From: ezequiel@collabora.com (Ezequiel Garcia)
To: linux-arm-kernel@lists.infradead.org
Subject: [RFC 2/3] USB: core: Add non-coherent buffer allocation helpers
Date: Thu, 30 Aug 2018 19:11:35 -0300 [thread overview]
Message-ID: <4fc5107f93871599ead017af7ad50f22535a7683.camel@collabora.com> (raw)
In-Reply-To: <20180830175850.GA11521@infradead.org>
On Thu, 2018-08-30 at 10:58 -0700, Christoph Hellwig wrote:
> Please don't introduce new DMA_ATTR_NON_CONSISTENT users, it is
> a rather horrible interface, and I plan to kill it off rather sooner
> than later. I plan to post some patches for a better interface
> that can reuse the normal dma_sync_single_* interfaces for ownership
> transfers. I can happily include usb in that initial patch set based
> on your work here if that helps.
Please do. Until we have proper allocators that go thru the DMA API,
drivers will have to kmalloc the USB transfer buffers, and have
streaming mappings. Which in turns mean not using IOMMU or CMA.
Regards,
Eze
next prev parent reply other threads:[~2018-08-30 22:11 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-08-30 17:20 [RFC 0/3] Introduce usb_{alloc,free}_noncoherent API Ezequiel Garcia
2018-08-30 17:20 ` Ezequiel Garcia
2018-08-30 17:20 ` [RFC 1/3] HACK: ARM: dma-mapping: Get writeback memory for non-consistent mappings Ezequiel Garcia
2018-08-30 17:20 ` Ezequiel Garcia
2018-08-30 17:20 ` [RFC,1/3] " Ezequiel Garcia
2018-08-30 17:20 ` [RFC 2/3] USB: core: Add non-coherent buffer allocation helpers Ezequiel Garcia
2018-08-30 17:20 ` Ezequiel Garcia
2018-08-30 17:20 ` [RFC,2/3] " Ezequiel Garcia
2018-08-30 17:58 ` [RFC 2/3] " Christoph Hellwig
2018-08-30 17:58 ` Christoph Hellwig
2018-08-30 17:58 ` [RFC,2/3] " Christoph Hellwig
2018-08-30 22:11 ` Ezequiel Garcia [this message]
2018-08-30 22:11 ` [RFC 2/3] " Ezequiel Garcia
2018-08-30 22:11 ` [RFC,2/3] " Ezequiel Garcia
2018-08-31 5:50 ` [RFC 2/3] " Christoph Hellwig
2018-08-31 5:50 ` Christoph Hellwig
2018-08-31 5:50 ` [RFC,2/3] " Christoph Hellwig
2018-08-31 6:51 ` [RFC 2/3] " Tomasz Figa
2018-08-31 6:51 ` Tomasz Figa
2018-08-31 6:51 ` [RFC,2/3] " Tomasz Figa
2018-10-31 1:55 ` [RFC 2/3] " Tomasz Figa
2018-10-31 1:55 ` Tomasz Figa
2018-10-31 1:55 ` [RFC,2/3] " Tomasz Figa
2018-08-30 17:20 ` [RFC 3/3] stk1160: Use non-coherent buffers for USB transfers Ezequiel Garcia
2018-08-30 17:20 ` Ezequiel Garcia
2018-08-30 17:20 ` [RFC,3/3] " Ezequiel Garcia
2018-08-30 17:59 ` [RFC 3/3] " Christoph Hellwig
2018-08-30 17:59 ` Christoph Hellwig
2018-08-30 17:59 ` [RFC,3/3] " Christoph Hellwig
2018-09-07 8:54 ` [RFC 3/3] " Tomasz Figa
2018-09-07 8:54 ` Tomasz Figa
2018-09-07 8:54 ` [RFC,3/3] " Tomasz Figa
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