From: "Guzman Lugo, Fernando" <fernando.lugo@ti.com>
To: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: "linux-omap@vger.kernel.org" <linux-omap@vger.kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"ohad@wizery.com" <ohad@wizery.com>,
"hiroshi.doyu@nokia.com" <hiroshi.doyu@nokia.com>,
"ameya.palande@nokia.com" <ameya.palande@nokia.com>,
"felipe.contreras@nokia.com" <felipe.contreras@nokia.com>
Subject: RE: [PATCH 8/9] dspbridge: add map support for big buffers
Date: Thu, 26 Aug 2010 08:16:24 -0500 [thread overview]
Message-ID: <496565EC904933469F292DDA3F1663E602F10ED4B3@dlee06.ent.ti.com> (raw)
In-Reply-To: <20100826215554N.fujita.tomonori@lab.ntt.co.jp>
>________________________________________
>From: FUJITA Tomonori [fujita.tomonori@lab.ntt.co.jp]
>Sent: Thursday, August 26, 2010 7:56 AM
>To: Guzman Lugo, Fernando
>Cc: fujita.tomonori@lab.ntt.co.jp; linux-omap@vger.kernel.org; linux-kernel@vger.kernel.org; ohad@wizery.com; hiroshi.doyu@nokia.com; ameya.palande@nokia.com; >felipe.contreras@nokia.com
>Subject: RE: [PATCH 8/9] dspbridge: add map support for big buffers
>
>On Thu, 26 Aug 2010 07:38:26 -0500
>"Guzman Lugo, Fernando" <fernando.lugo@ti.com> wrote:
>
>> >> due to a restriction in scatter gather lists, it can
>> >> not be created a list for a buffer bigger than 1MB.
>> >> This patch is spliting big mappings into 1MB mappings.
>> >
>> >I don't read the whole thread but the above description is incorrect.
>> >
>> >Why can't you use scatter gather chaining? You can create a scatter
>> >list for a buffer larger than 1MB.
>>
>> The thing is that ARM architecture does not support SG chaining. This patch should be
>> seen like a workaround until it is fixed in iovmm module.
>
>Fix iovmm module is easier than the workaround?
I have not thought about possible fixes inside iovmm, but now I am reviewing the
patches I will figure out how to fix this inside iovmm. Since he workaround still
can fail to allocate big buffers even though there is space to allocate it.
>
>From a quick look, arch/arm/plat-omap/iovmm.c does nothing wrong about
>scatter gather chaining. arm/arm/mm/dma-mapping.c looks fine too about
>it. Maybe just defining ARCH_HAS_SG_CHAIN works?
I can try, but it looks tricky for me. Maybe someone else can tell us why
SG chain is not supported for ARM or if there is a problem just defining
ARCH_HAS_SG_CHAIN.
Regards,
Fernando.
next prev parent reply other threads:[~2010-08-26 13:16 UTC|newest]
Thread overview: 51+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-07-01 0:20 [PATCH 0/9] dspbridge: iommu migration Fernando Guzman Lugo
2010-07-01 0:20 ` Fernando Guzman Lugo
2010-07-01 0:20 ` [PATCH 1/9] dspbridge: replace iommu custom for opensource implementation Fernando Guzman Lugo
2010-07-01 0:20 ` Fernando Guzman Lugo
2010-07-01 0:20 ` [PATCH 2/9] dspbridge: move shared memory iommu maps to tiomap3430.c Fernando Guzman Lugo
2010-07-01 0:20 ` Fernando Guzman Lugo
2010-07-01 0:20 ` [PATCH 3/9] dspbridge: rename bridge_brd_mem_map/unmap to a proper name Fernando Guzman Lugo
2010-07-01 0:20 ` Fernando Guzman Lugo
2010-07-01 0:20 ` [PATCH 4/9] dspbridge: remove custom mmu code from tiomap3430.c Fernando Guzman Lugo
2010-07-01 0:20 ` Fernando Guzman Lugo
2010-07-01 0:20 ` [PATCH 5/9] dspbridge: add mmufault support Fernando Guzman Lugo
2010-07-01 0:20 ` Fernando Guzman Lugo
2010-07-01 0:20 ` [PATCH 6/9] dspbridge: remove hw directory Fernando Guzman Lugo
2010-07-01 0:20 ` Fernando Guzman Lugo
2010-07-01 0:20 ` [PATCH 7/9] dspbridge: move all iommu related code to a new file Fernando Guzman Lugo
2010-07-01 0:20 ` Fernando Guzman Lugo
2010-07-01 0:20 ` [PATCH 8/9] dspbridge: add map support for big buffers Fernando Guzman Lugo
2010-07-01 0:20 ` Fernando Guzman Lugo
2010-07-01 0:21 ` [PATCH 9/9] dspbridge: cleanup bridge_dev_context and cfg_hostres structures Fernando Guzman Lugo
2010-07-01 0:21 ` Fernando Guzman Lugo
2010-07-01 23:36 ` [PATCH 8/9] dspbridge: add map support for big buffers Kanigeri, Hari
2010-07-01 23:36 ` Kanigeri, Hari
2010-07-02 16:27 ` Guzman Lugo, Fernando
2010-07-02 17:02 ` Kanigeri, Hari
2010-07-02 18:39 ` Guzman Lugo, Fernando
2010-08-24 10:09 ` Felipe Contreras
2010-08-24 16:31 ` Guzman Lugo, Fernando
2010-08-24 17:46 ` Felipe Contreras
2010-08-24 18:44 ` Guzman Lugo, Fernando
2010-08-24 18:55 ` Felipe Contreras
2010-08-24 19:05 ` Guzman Lugo, Fernando
2010-08-24 19:13 ` Felipe Contreras
2010-08-24 19:30 ` Guzman Lugo, Fernando
2010-08-24 21:17 ` Felipe Contreras
2010-08-24 21:55 ` Guzman Lugo, Fernando
2010-08-25 6:05 ` Felipe Contreras
2010-08-25 16:00 ` Guzman Lugo, Fernando
2010-08-25 19:18 ` Felipe Contreras
2010-08-25 19:42 ` Guzman Lugo, Fernando
2010-08-26 10:04 ` Felipe Contreras
2010-08-26 13:00 ` Guzman Lugo, Fernando
2010-08-26 6:55 ` FUJITA Tomonori
2010-08-26 12:38 ` Guzman Lugo, Fernando
2010-08-26 12:56 ` FUJITA Tomonori
2010-08-26 13:16 ` Guzman Lugo, Fernando [this message]
2010-08-26 14:03 ` FUJITA Tomonori
2010-08-26 14:13 ` Guzman Lugo, Fernando
2010-07-02 6:27 ` [PATCH 5/9] dspbridge: add mmufault support Hiroshi DOYU
2010-07-02 16:37 ` Guzman Lugo, Fernando
2010-07-02 6:32 ` [PATCH 1/9] dspbridge: replace iommu custom for opensource implementation Hiroshi DOYU
2010-07-02 16:40 ` Guzman Lugo, Fernando
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