From: Will Deacon <will.deacon@arm.com>
To: "Niklas Söderlund" <niklas.soderlund+renesas@ragnatech.se>
Cc: linux-arm-kernel@lists.infradead.org,
iommu@lists.linux-foundation.org, dmaengine@vger.kernel.org,
joro@8bytes.org, linux-kernel@vger.kernel.org,
linux-renesas-soc@vger.kernel.org, robin.murphy@arm.com
Subject: Re: [PATCH 2/2] iommu/io-pgtable-arm: use __dma_sync_single_for_device()
Date: Mon, 9 May 2016 10:35:41 +0100 [thread overview]
Message-ID: <20160509093540.GF19763@arm.com> (raw)
In-Reply-To: <1462705196-10857-3-git-send-email-niklas.soderlund+renesas@ragnatech.se>
On Sun, May 08, 2016 at 12:59:56PM +0200, Niklas Söderlund wrote:
> The call to dma_sync_single_for_device() can be reached from
> dma_map_single(). If CONFIG_DMA_API_DEBUG is enabled this would result
> in a check that the mapping being synced is valid. Since the call to
> dma_map_single is not yet completed the mapping is not recorded in
> dma-debug and the check fails and a warning is printed. Avoid this
> warning by calling __dma_sync_single_for_device() which don't preform
> this check.
Hmm, I don't understand why this would trigger that warning. The memory
being sync'd here is the page table memory, not the buffer being mapped.
The page table memory is "mapped" using dma_map_single in
__arm_lpae_alloc_pages, so it sounds like the issue something else.
Will
WARNING: multiple messages have this Message-ID (diff)
From: Will Deacon <will.deacon@arm.com>
To: "Niklas Söderlund" <niklas.soderlund+renesas@ragnatech.se>
Cc: linux-arm-kernel@lists.infradead.org,
iommu@lists.linux-foundation.org, dmaengine@vger.kernel.org,
joro@8bytes.org, linux-kernel@vger.kernel.org,
linux-renesas-soc@vger.kernel.org, robin.murphy@arm.com
Subject: Re: [PATCH 2/2] iommu/io-pgtable-arm: use __dma_sync_single_for_device()
Date: Mon, 9 May 2016 10:35:41 +0100 [thread overview]
Message-ID: <20160509093540.GF19763@arm.com> (raw)
In-Reply-To: <1462705196-10857-3-git-send-email-niklas.soderlund+renesas@ragnatech.se>
On Sun, May 08, 2016 at 12:59:56PM +0200, Niklas S�derlund wrote:
> The call to dma_sync_single_for_device() can be reached from
> dma_map_single(). If CONFIG_DMA_API_DEBUG is enabled this would result
> in a check that the mapping being synced is valid. Since the call to
> dma_map_single is not yet completed the mapping is not recorded in
> dma-debug and the check fails and a warning is printed. Avoid this
> warning by calling __dma_sync_single_for_device() which don't preform
> this check.
Hmm, I don't understand why this would trigger that warning. The memory
being sync'd here is the page table memory, not the buffer being mapped.
The page table memory is "mapped" using dma_map_single in
__arm_lpae_alloc_pages, so it sounds like the issue something else.
Will
WARNING: multiple messages have this Message-ID (diff)
From: will.deacon@arm.com (Will Deacon)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH 2/2] iommu/io-pgtable-arm: use __dma_sync_single_for_device()
Date: Mon, 9 May 2016 10:35:41 +0100 [thread overview]
Message-ID: <20160509093540.GF19763@arm.com> (raw)
In-Reply-To: <1462705196-10857-3-git-send-email-niklas.soderlund+renesas@ragnatech.se>
On Sun, May 08, 2016 at 12:59:56PM +0200, Niklas S?derlund wrote:
> The call to dma_sync_single_for_device() can be reached from
> dma_map_single(). If CONFIG_DMA_API_DEBUG is enabled this would result
> in a check that the mapping being synced is valid. Since the call to
> dma_map_single is not yet completed the mapping is not recorded in
> dma-debug and the check fails and a warning is printed. Avoid this
> warning by calling __dma_sync_single_for_device() which don't preform
> this check.
Hmm, I don't understand why this would trigger that warning. The memory
being sync'd here is the page table memory, not the buffer being mapped.
The page table memory is "mapped" using dma_map_single in
__arm_lpae_alloc_pages, so it sounds like the issue something else.
Will
next prev parent reply other threads:[~2016-05-09 9:35 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-05-08 10:59 [PATCH 0/2] Fix incorrect warning from dma-debug Niklas Söderlund
2016-05-08 10:59 ` Niklas Söderlund
2016-05-08 10:59 ` [PATCH 1/2] dma-mapping: add __dma_sync_single_for_device() Niklas Söderlund
2016-05-08 10:59 ` Niklas Söderlund
2016-05-08 10:59 ` [PATCH 2/2] iommu/io-pgtable-arm: use __dma_sync_single_for_device() Niklas Söderlund
2016-05-08 10:59 ` Niklas Söderlund
2016-05-09 9:35 ` Will Deacon [this message]
2016-05-09 9:35 ` Will Deacon
2016-05-09 9:35 ` Will Deacon
2016-05-09 9:37 ` [PATCH 0/2] Fix incorrect warning from dma-debug Robin Murphy
2016-05-09 9:37 ` Robin Murphy
2016-05-09 10:00 ` Robin Murphy
2016-05-09 10:00 ` Robin Murphy
2017-05-07 0:06 ` Jon Masters
2017-05-07 0:06 ` Jon Masters
2017-05-08 9:19 ` Geert Uytterhoeven
2017-05-08 9:19 ` Geert Uytterhoeven
2017-05-08 9:39 ` Robin Murphy
2017-05-08 9:39 ` Robin Murphy
2017-01-25 16:23 ` Geert Uytterhoeven
2017-01-25 16:23 ` Geert Uytterhoeven
[not found] ` <CAMuHMdUnznBCt=V5_PgTaXM5JAZjBvZK-44bahUx+7NFg+f0rA-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2017-01-25 17:27 ` Robin Murphy
2017-01-25 17:27 ` Robin Murphy
2017-01-25 17:27 ` Robin Murphy
2017-01-25 20:32 ` Geert Uytterhoeven
2017-01-25 20:32 ` Geert Uytterhoeven
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