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From: Murali Karicheri <m-karicheri2@ti.com>
To: Arnd Bergmann <arnd@arndb.de>
Cc: bhelgaas@google.com, linux-arm-kernel@lists.infradead.org,
	joro@8bytes.org, grant.likely@linaro.org, robh+dt@kernel.org,
	iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org,
	devicetree@vger.kernel.org, linux-pci@vger.kernel.org,
	will.deacon@arm.com, linux@arm.linux.org.uk
Subject: Re: [PATCH v3 0/4] PCI: get DMA configuration from parent device
Date: Thu, 8 Jan 2015 17:46:31 -0500	[thread overview]
Message-ID: <54AF08C7.2010100@ti.com> (raw)
In-Reply-To: <2785994.gTZ9chGdKf@wuerfel>

On 01/08/2015 05:27 PM, Arnd Bergmann wrote:
> On Thursday 08 January 2015 09:56:39 Arnd Bergmann wrote:
>> There is another interesting case, which is a USB host controller or
>> something similar behind a PCI bus. These are quite common and also
>> need to be handled in some form. Let's do just PCI first for now, but
>> be aware that this will come next. Should we assume that the ID that
>> is required for a device is either known from the device node, or
>> that it comes from a PCI device? That means for the USB case, we will
>> likely need to have some custom logic. There seems to be an implicit
>> assumption all over the kernel that all devices have the same IOMMU
>> instance, but we can't really rely on that here.
>>
>
> Update: I've checked the USB implementation and we are lucky because
> these interactions are all done by the USB host controller, and a
> USB device is not itself DMA capable. We don't have to do anything
> for USB.

Ok Thanks.

Murali
>
> 	Arnd
> --
> To unsubscribe from this list: send the line "unsubscribe linux-pci" in
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-- 
Murali Karicheri
Linux Kernel, Texas Instruments

      reply	other threads:[~2015-01-08 22:46 UTC|newest]

Thread overview: 30+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-01-07 18:49 [PATCH v3 0/4] PCI: get DMA configuration from parent device Murali Karicheri
     [not found] ` <1420656594-8908-1-git-send-email-m-karicheri2-l0cyMroinI0@public.gmane.org>
2015-01-07 18:49   ` [PATCH v3 1/4] of: iommu: add ptr to OF node arg to of_iommu_configure() Murali Karicheri
     [not found]     ` <1420656594-8908-2-git-send-email-m-karicheri2-l0cyMroinI0@public.gmane.org>
2015-01-07 23:30       ` Rob Herring
2015-01-08 18:29         ` Murali Karicheri
2015-01-07 23:05   ` [PATCH v3 0/4] PCI: get DMA configuration from parent device Murali Karicheri
     [not found]     ` <54ADBBCF.8020206-l0cyMroinI0@public.gmane.org>
2015-01-07 23:08       ` Bjorn Helgaas
     [not found]         ` <CAErSpo46UAn9ckbzrgzAoQbu2D=oyOOL_rO24NWEg_iDLSuCLA-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2015-01-08 15:52           ` Murali Karicheri
2015-01-07 18:49 ` [PATCH v3 2/4] of: move of_dma_configure() to device,c to help re-use Murali Karicheri
2015-01-07 23:37   ` Rob Herring
     [not found]     ` <CAL_Jsq+pKeXuGnZV_NYHn6iZgeOs404OPhcUb0FJs=-7j2P1Ug-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2015-01-08  8:40       ` [PATCH v3 2/4] of: move of_dma_configure() to device, c " Arnd Bergmann
2015-01-08 19:26         ` [PATCH v3 2/4] of: move of_dma_configure() to device,c " Murali Karicheri
2015-01-08 22:24           ` Arnd Bergmann
2015-01-08 23:44             ` Murali Karicheri
     [not found]               ` <54AF165F.7070909-l0cyMroinI0@public.gmane.org>
2015-01-09  0:05                 ` Arnd Bergmann
2015-01-09 15:34             ` Rob Herring
2015-01-23 18:19               ` Murali Karicheri
2015-01-23 18:35                 ` Rob Herring
2015-01-07 18:49 ` [PATCH v3 3/4] of/pci: add of_pci_dma_configure() update dma configuration Murali Karicheri
2015-01-08 16:06   ` Will Deacon
2015-01-08 19:52     ` Murali Karicheri
     [not found]       ` <54AEDFED.8060008-l0cyMroinI0@public.gmane.org>
2015-01-08 22:25         ` Arnd Bergmann
2015-01-08 22:46           ` Murali Karicheri
2015-01-09 11:32           ` Will Deacon
2015-01-07 18:49 ` [PATCH v3 4/4] PCI: update dma configuration from DT Murali Karicheri
2015-01-07 21:18 ` [PATCH v3 0/4] PCI: get DMA configuration from parent device Arnd Bergmann
2015-01-07 23:04   ` Murali Karicheri
     [not found]     ` <54ADBB89.8070503-l0cyMroinI0@public.gmane.org>
2015-01-08  8:56       ` Arnd Bergmann
2015-01-08 15:54         ` Will Deacon
2015-01-08 22:27         ` Arnd Bergmann
2015-01-08 22:46           ` Murali Karicheri [this message]

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