From: Russell King - ARM Linux <linux@arm.linux.org.uk>
To: KyongHo Cho <pullip.cho@samsung.com>
Cc: linux-arch@vger.kernel.org, Arnd Bergmann <arnd@arndb.de>,
Joerg Roedel <joro@8bytes.org>,
linaro-mm-sig@lists.linaro.org, linux-mm@kvack.org,
Kyungmin Park <kyungmin.park@samsung.com>,
linux-arm-kernel@lists.infradead.org,
Marek Szyprowski <m.szyprowski@samsung.com>
Subject: Re: [PATCH 7/8] common: dma-mapping: change alloc/free_coherent method to more generic alloc/free_attrs
Date: Mon, 20 Jun 2011 16:06:10 +0100 [thread overview]
Message-ID: <20110620150610.GG26089@n2100.arm.linux.org.uk> (raw)
In-Reply-To: <BANLkTikFdrOuXsLCfvyA_V+p7S_fd72dyQ@mail.gmail.com>
On Mon, Jun 20, 2011 at 11:45:41PM +0900, KyongHo Cho wrote:
> I still don't agree with your idea that change alloc_coherent() with alloc().
> As I said before, we actually do not need dma_alloc_writecombine() anymore
> because it is not different from dma_alloc_coherent() in ARM.
Wrong - there is a difference. For pre-ARMv6 CPUs, it returns memory
with different attributes from DMA coherent memory.
And we're not going to sweep away pre-ARMv6 CPUs any time soon. So
you can't ignore dma_alloc_writecombine() which must remain to sanely
support framebuffers.
WARNING: multiple messages have this Message-ID (diff)
From: Russell King - ARM Linux <linux@arm.linux.org.uk>
To: KyongHo Cho <pullip.cho@samsung.com>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>,
linux-arm-kernel@lists.infradead.org,
linaro-mm-sig@lists.linaro.org, linux-mm@kvack.org,
linux-arch@vger.kernel.org,
Kyungmin Park <kyungmin.park@samsung.com>,
Arnd Bergmann <arnd@arndb.de>, Joerg Roedel <joro@8bytes.org>
Subject: Re: [PATCH 7/8] common: dma-mapping: change alloc/free_coherent method to more generic alloc/free_attrs
Date: Mon, 20 Jun 2011 16:06:10 +0100 [thread overview]
Message-ID: <20110620150610.GG26089@n2100.arm.linux.org.uk> (raw)
Message-ID: <20110620150610.3hT7JhHnhcABZQ9BUAhOfUMyX3VEAiy4NZIyID1090U@z> (raw)
In-Reply-To: <BANLkTikFdrOuXsLCfvyA_V+p7S_fd72dyQ@mail.gmail.com>
On Mon, Jun 20, 2011 at 11:45:41PM +0900, KyongHo Cho wrote:
> I still don't agree with your idea that change alloc_coherent() with alloc().
> As I said before, we actually do not need dma_alloc_writecombine() anymore
> because it is not different from dma_alloc_coherent() in ARM.
Wrong - there is a difference. For pre-ARMv6 CPUs, it returns memory
with different attributes from DMA coherent memory.
And we're not going to sweep away pre-ARMv6 CPUs any time soon. So
you can't ignore dma_alloc_writecombine() which must remain to sanely
support framebuffers.
next prev parent reply other threads:[~2011-06-20 15:06 UTC|newest]
Thread overview: 94+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-06-20 7:50 [PATCH/RFC 0/8] ARM: DMA-mapping framework redesign Marek Szyprowski
2011-06-20 7:50 ` [PATCH 1/8] ARM: dma-mapping: remove offset parameter to prepare for generic dma_ops Marek Szyprowski
2011-06-20 8:35 ` Michal Nazarewicz
2011-06-20 10:46 ` Marek Szyprowski
2011-06-20 10:46 ` Marek Szyprowski
2011-07-03 15:28 ` Russell King - ARM Linux
2011-07-03 15:28 ` Russell King - ARM Linux
2011-07-26 12:56 ` Marek Szyprowski
2011-06-20 7:50 ` [PATCH 2/8] ARM: dma-mapping: implement dma_map_single on top of dma_map_page Marek Szyprowski
2011-06-20 14:39 ` Russell King - ARM Linux
2011-06-20 14:39 ` Russell King - ARM Linux
2011-06-20 15:15 ` Marek Szyprowski
2011-06-24 15:24 ` Arnd Bergmann
2011-06-24 15:24 ` Arnd Bergmann
2011-06-27 14:29 ` Marek Szyprowski
2011-06-27 14:53 ` Arnd Bergmann
2011-06-27 14:53 ` Arnd Bergmann
2011-06-27 15:06 ` Marek Szyprowski
2011-06-20 7:50 ` [PATCH 3/8] ARM: dma-mapping: use asm-generic/dma-mapping-common.h Marek Szyprowski
2011-06-20 14:33 ` [Linaro-mm-sig] " KyongHo Cho
2011-06-21 11:47 ` Marek Szyprowski
2011-06-21 11:47 ` Marek Szyprowski
2011-06-24 8:39 ` 'Joerg Roedel'
2011-06-24 8:39 ` 'Joerg Roedel'
2011-06-24 15:36 ` Arnd Bergmann
2011-06-24 15:36 ` Arnd Bergmann
2011-06-27 12:18 ` Marek Szyprowski
2011-06-27 12:18 ` Marek Szyprowski
2011-06-27 13:19 ` Arnd Bergmann
2011-06-27 13:19 ` Arnd Bergmann
2011-07-07 12:09 ` Lennert Buytenhek
2011-07-07 12:09 ` Lennert Buytenhek
2011-07-07 12:38 ` Russell King - ARM Linux
2011-07-07 12:38 ` Russell King - ARM Linux
2011-07-15 0:10 ` Lennert Buytenhek
2011-07-15 9:27 ` Russell King - ARM Linux
2011-07-15 9:27 ` Russell King - ARM Linux
2011-07-15 21:53 ` Lennert Buytenhek
2011-06-20 7:50 ` [PATCH 4/8] ARM: dma-mapping: implement dma sg methods on top of generic dma ops Marek Szyprowski
2011-06-20 7:50 ` Marek Szyprowski
2011-06-20 14:37 ` KyongHo Cho
2011-06-20 14:40 ` Russell King - ARM Linux
2011-06-20 14:40 ` Russell King - ARM Linux
2011-06-20 15:23 ` Marek Szyprowski
2011-06-20 7:50 ` [PATCH 5/8] ARM: dma-mapping: move all dma bounce code to separate dma ops structure Marek Szyprowski
2011-06-20 14:42 ` Russell King - ARM Linux
2011-06-20 15:31 ` Marek Szyprowski
2011-06-20 15:31 ` Marek Szyprowski
2011-06-24 15:47 ` Arnd Bergmann
2011-06-24 15:47 ` Arnd Bergmann
2011-06-27 14:20 ` Marek Szyprowski
2011-06-27 14:20 ` Marek Szyprowski
2011-06-20 7:50 ` [PATCH 6/8] ARM: dma-mapping: remove redundant code and cleanup Marek Szyprowski
2011-06-20 7:50 ` [PATCH 7/8] common: dma-mapping: change alloc/free_coherent method to more generic alloc/free_attrs Marek Szyprowski
2011-06-20 14:45 ` KyongHo Cho
2011-06-20 15:06 ` Russell King - ARM Linux [this message]
2011-06-20 15:06 ` Russell King - ARM Linux
2011-06-20 15:14 ` [Linaro-mm-sig] " KyongHo Cho
2011-06-21 11:23 ` Marek Szyprowski
2011-06-22 0:00 ` [Linaro-mm-sig] " KyongHo Cho
2011-06-24 7:20 ` Marek Szyprowski
2011-06-24 15:51 ` Arnd Bergmann
2011-06-24 15:51 ` Arnd Bergmann
2011-06-24 16:15 ` James Bottomley
2011-06-24 16:23 ` Arnd Bergmann
2011-06-27 12:23 ` Marek Szyprowski
2011-06-27 12:23 ` Marek Szyprowski
2011-06-27 13:22 ` Arnd Bergmann
2011-06-27 13:22 ` Arnd Bergmann
2011-06-27 13:30 ` Marek Szyprowski
2011-06-27 13:30 ` Marek Szyprowski
2011-06-24 15:53 ` Arnd Bergmann
2011-06-24 15:53 ` Arnd Bergmann
2011-06-27 14:41 ` Marek Szyprowski
2011-06-20 7:50 ` [PATCH 8/8] ARM: dma-mapping: use alloc, mmap, free from dma_ops Marek Szyprowski
2011-06-22 6:53 ` [Linaro-mm-sig] " KyongHo Cho
2011-06-22 4:53 ` [Linaro-mm-sig] [PATCH/RFC 0/8] ARM: DMA-mapping framework redesign Subash Patel
2011-06-22 6:59 ` Marek Szyprowski
2011-06-22 6:59 ` Marek Szyprowski
2011-06-22 8:53 ` Subash Patel
2011-06-22 9:27 ` Marek Szyprowski
2011-06-22 16:00 ` Jordan Crouse
2011-06-23 13:09 ` Subash Patel
2011-06-23 13:09 ` Subash Patel
2011-06-23 16:24 ` Michael K. Edwards
2011-06-23 22:09 ` Michael K. Edwards
2011-06-25 5:23 ` Jonathan Morton
2011-06-25 5:23 ` Jonathan Morton
2011-06-25 9:55 ` Michael K. Edwards
2011-06-26 0:06 ` Jonathan Morton
2011-06-24 15:20 ` Arnd Bergmann
2011-06-24 15:20 ` Arnd Bergmann
2011-06-24 9:18 ` Joerg Roedel
2011-06-24 14:26 ` Marek Szyprowski
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