From be36ea5f2c7d1c28dc8f829b5d2c817826481086 Mon Sep 17 00:00:00 2001 From: Laurent Pinchart Date: Fri, 15 May 2015 02:00:02 +0300 Subject: [PATCH] arm: dma-mapping: Don't override dma_ops in arch_setup_dma_ops() The arch_setup_dma_ops() function is in charge of setting dma_ops with a call to set_dma_ops(). set_dma_ops() is also called from - highbank and mvebu bus notifiers - dmabounce (to be replaced with swiotlb) - arm_iommu_attach_device (arm_iommu_attach_device is itself called from IOMMU and bus master device drivers) To allow the arch_setup_dma_ops() call to be moved from device add time to device probe time we must ensure that dma_ops already setup by any of the above callers will not be overriden. Aftering replacing dmabounce with swiotlb, converting IOMMU drivers to of_xlate and taking care of highbank and mvebu, the workaround should be removed. [Rebased on top of 4.11-rc8] Signed-off-by: Sricharan R Signed-off-by: Laurent Pinchart --- arch/arm/mm/dma-mapping.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c index 0268584..c742dfd 100644 --- a/arch/arm/mm/dma-mapping.c +++ b/arch/arm/mm/dma-mapping.c @@ -2408,6 +2408,15 @@ void arch_setup_dma_ops(struct device *dev, u64 dma_base, u64 size, const struct dma_map_ops *dma_ops; dev->archdata.dma_coherent = coherent; + + /* + * Don't override the dma_ops if they have already been set. Ideally + * this should be the only location where dma_ops are set, remove this + * check when all other callers of set_dma_ops will have disappeared. + */ + if (dev->dma_ops) + return; + if (arm_setup_iommu_dma_ops(dev, dma_base, size, iommu)) dma_ops = arm_get_iommu_dma_map_ops(coherent); else -- QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation