From: Marek Szyprowski <m.szyprowski@samsung.com>
To: "'Hiroshi Doyu'" <hdoyu@nvidia.com>
Cc: linux-arm-kernel@lists.infradead.org,
linaro-mm-sig@lists.linaro.org, linux-mm@kvack.org,
linux-kernel@vger.kernel.org, kyungmin.park@samsung.com,
arnd@arndb.de, linux@arm.linux.org.uk, chunsang.jeong@linaro.org,
"'Krishna Reddy'" <vdumpa@nvidia.com>,
konrad.wilk@oracle.com, subashrp@gmail.com, minchan@kernel.org
Subject: RE: [RFC 0/4] ARM: dma-mapping: IOMMU atomic allocation
Date: Wed, 22 Aug 2012 14:04:26 +0200 [thread overview]
Message-ID: <005901cd805e$4afd2e40$e0f78ac0$%szyprowski@samsung.com> (raw)
In-Reply-To: <1345630830-9586-1-git-send-email-hdoyu@nvidia.com>
Hi Hiroshi,
On Wednesday, August 22, 2012 12:20 PM Hiroshi Doyu wrote:
> The commit e9da6e9 "ARM: dma-mapping: remove custom consistent dma
> region" breaks the compatibility with existing drivers. This causes
> the following kernel oops(*1). That driver has called dma_pool_alloc()
> to allocate memory from the interrupt context, and it hits
> BUG_ON(in_interrpt()) in "get_vm_area_caller()". This patch seris
> fixes this problem with making use of the pre-allocate atomic memory
> pool which DMA is using in the same way as DMA does now.
>
> Any comment would be really appreciated.
I was working on the similar patches, but You were faster. ;-)
Basically the patch no 1 and 2 are fine, but I don't like the changes proposed in
patch 3 and 4. You should not alter the attributes provided by the user nor make any
assumptions that such attributes has been provided - drivers are allowed to call
dma_alloc_attrs() directly. Please rework your patches to avoid such approach.
Best regards
--
Marek Szyprowski
Samsung Poland R&D Center
next prev parent reply other threads:[~2012-08-22 12:04 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-08-22 10:20 [RFC 0/4] ARM: dma-mapping: IOMMU atomic allocation Hiroshi Doyu
2012-08-22 10:20 ` [RFC 1/4] ARM: dma-mapping: Refactor out to introduce __alloc_fill_pages Hiroshi Doyu
2012-08-22 10:20 ` [RFC 2/4] ARM: dma-mapping: IOMMU allocates pages from pool with GFP_ATOMIC Hiroshi Doyu
2012-08-22 12:29 ` Marek Szyprowski
2012-08-22 12:52 ` Hiroshi Doyu
[not found] ` <CAHQjnOOF7Ca-Dz8K_zcS=gxQsJvKYaWA3tqUeK1RSd-wLYZ44w@mail.gmail.com>
2012-08-22 13:36 ` Hiroshi Doyu
2012-08-23 3:49 ` Minchan Kim
2012-08-23 5:58 ` Marek Szyprowski
2012-08-23 6:15 ` Hiroshi Doyu
2012-08-23 7:52 ` Marek Szyprowski
2012-08-22 10:20 ` [RFC 3/4] ARM: dma-mapping: Return cpu addr when dma_alloc(GFP_ATOMIC) Hiroshi Doyu
2012-08-22 10:20 ` [RFC 4/4] ARM: dma-mapping: dma_{alloc,free}_coherent with empty attrs Hiroshi Doyu
2012-08-22 12:04 ` Marek Szyprowski [this message]
2012-08-22 14:44 ` [RFC 0/4] ARM: dma-mapping: IOMMU atomic allocation Hiroshi Doyu
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