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| author |   Christoph Hellwig <hch@lst.de> | 2022-10-04 09:10:19 +0200 |
|---|---|---|
| committer | Christoph Hellwig <hch@lst.de> | 2022-10-06 14:30:51 +0200 |
| commit | 49bc8bebae79c8516cb12f91818f3a7907e3ebce (patch) | |
| tree | d574a81615e2932c54ff2287b7a459c583d7f4c1 /arch/arm/mm/dma-mapping.c | |
| parent | lib/sg_pool: change module_init(sg_pool_init) to subsys_initcall (diff) | |
| download | linux-dev-49bc8bebae79c8516cb12f91818f3a7907e3ebce.tar.xz linux-dev-49bc8bebae79c8516cb12f91818f3a7907e3ebce.zip | |
ARM/dma-mappіng: don't override ->dma_coherent when set from a bus notifier
Commit ae626eb97376 ("ARM/dma-mapping: use dma-direct unconditionally")
caused a regression on the mvebu platform, wherein devices that are
dma-coherent are marked as dma-noncoherent, because although
mvebu_hwcc_notifier() after that commit still marks then as coherent,
the arm_coherent_dma_ops() function, which is called later, overwrites
this setting, since it is being called from drivers/of/device.c with
coherency parameter determined by of_dma_is_coherent(), and the
device-trees do not declare the 'dma-coherent' property.
Fix this by defaulting never clearing the dma_coherent flag in
arm_coherent_dma_ops().
Fixes: ae626eb97376 ("ARM/dma-mapping: use dma-direct unconditionally")
Reported-by: Marek Behún <kabel@kernel.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Tested-by: Marek Behún <kabel@kernel.org>
Diffstat (limited to 'arch/arm/mm/dma-mapping.c')
| -rw-r--r-- | arch/arm/mm/dma-mapping.c | 12 |
1 files changed, 10 insertions, 2 deletions
diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c index 089c9c644cce..bfc7476f1411 100644 --- a/arch/arm/mm/dma-mapping.c +++ b/arch/arm/mm/dma-mapping.c @@ -1769,8 +1769,16 @@ static void arm_teardown_iommu_dma_ops(struct device *dev) { } void arch_setup_dma_ops(struct device *dev, u64 dma_base, u64 size, const struct iommu_ops *iommu, bool coherent) { - dev->archdata.dma_coherent = coherent; - dev->dma_coherent = coherent; + /* + * Due to legacy code that sets the ->dma_coherent flag from a bus + * notifier we can't just assign coherent to the ->dma_coherent flag + * here, but instead have to make sure we only set but never clear it + * for now. + */ + if (coherent) { + dev->archdata.dma_coherent = true; + dev->dma_coherent = true; + } /* * Don't override the dma_ops if they have already been set. Ideally |