diff options
| author |   Kumar Gala <galak@kernel.crashing.org> | 2011-06-10 02:22:06 -0500 |
|---|---|---|
| committer | Kumar Gala <galak@kernel.crashing.org> | 2011-07-08 00:21:36 -0500 |
| commit | 6471fc6630a507fd54fdaceceee1ddaf3c917cde (patch) | |
| tree | 0532ac8edd4caef745dd28a56979cdb5037c464b /arch/powerpc/kernel/dma.c | |
| parent | powerpc: implement arch_setup_pdev_archdata (diff) | |
| download | linux-dev-6471fc6630a507fd54fdaceceee1ddaf3c917cde.tar.xz linux-dev-6471fc6630a507fd54fdaceceee1ddaf3c917cde.zip | |
powerpc: Dont require a dma_ops struct to set dma mask
The only reason to require a dma_ops struct is to see if it has
implemented set_dma_mask. If not we can fall back to setting the mask
directly.
This resolves an issue with how to sequence the setting of a DMA mask
for platform devices. Before we had an issue in that we have no way of
setting the DMA mask before the various low level bus notifiers get
called that might check it (swiotlb).
So now we can do:
pdev = platform_device_alloc("foobar", 0);
dma_set_mask(&pdev->dev, DMA_BIT_MASK(37));
platform_device_add(pdev);
And expect the right thing to happen with the bus notifiers get called
via platform_device_add.
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
Diffstat (limited to 'arch/powerpc/kernel/dma.c')
| -rw-r--r-- | arch/powerpc/kernel/dma.c | 4 |
1 files changed, 1 insertions, 3 deletions
diff --git a/arch/powerpc/kernel/dma.c b/arch/powerpc/kernel/dma.c index d238c082c3c5..4f0959fbfbee 100644 --- a/arch/powerpc/kernel/dma.c +++ b/arch/powerpc/kernel/dma.c @@ -161,9 +161,7 @@ int dma_set_mask(struct device *dev, u64 dma_mask) if (ppc_md.dma_set_mask) return ppc_md.dma_set_mask(dev, dma_mask); - if (unlikely(dma_ops == NULL)) - return -EIO; - if (dma_ops->set_dma_mask != NULL) + if ((dma_ops != NULL) && (dma_ops->set_dma_mask != NULL)) return dma_ops->set_dma_mask(dev, dma_mask); if (!dev->dma_mask || !dma_supported(dev, dma_mask)) return -EIO; |