RE: [RFC 0/4] ARM: dma-mapping: IOMMU atomic allocation
From: Marek Szyprowski <m.szyprowski@samsung.com>
Date: 2012-08-22 12:04:47
Also in:
linux-arm-kernel, lkml
From: Marek Szyprowski <m.szyprowski@samsung.com>
Date: 2012-08-22 12:04:47
Also in:
linux-arm-kernel, lkml
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 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>