diff options
author | Robin Murphy <robin.murphy@arm.com> | 2018-07-24 00:16:12 +0200 |
---|---|---|
committer | Christoph Hellwig <hch@lst.de> | 2018-07-27 19:01:07 +0200 |
commit | 4d8bde883bfba3e8dd3335f91b640e5a70ec0aa6 (patch) | |
tree | ef98a3deb3a6de05ef4ab94e54df266aad331d1a /drivers/of | |
parent | ACPI/IORT: Don't set default coherent DMA mask (diff) | |
download | linux-4d8bde883bfba3e8dd3335f91b640e5a70ec0aa6.tar.xz linux-4d8bde883bfba3e8dd3335f91b640e5a70ec0aa6.zip |
OF: Don't set default coherent DMA mask
Now that we can track upstream DMA constraints properly with
bus_dma_mask instead of trying (and failing) to maintain it in
coherent_dma_mask, it doesn't make much sense for the firmware code to
be touching the latter at all. It's merely papering over bugs wherein a
driver has failed to call dma_set_coherent_mask() *and* the bus code has
not initialised any default value.
We don't really want to encourage more drivers coercing dma_mask so
we'll continue to fix that up if necessary, but add a warning to help
flush out any such buggy bus code that remains.
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Diffstat (limited to 'drivers/of')
-rw-r--r-- | drivers/of/device.c | 20 |
1 files changed, 10 insertions, 10 deletions
diff --git a/drivers/of/device.c b/drivers/of/device.c index 0d39633e8545..5957cd4fa262 100644 --- a/drivers/of/device.c +++ b/drivers/of/device.c @@ -127,20 +127,20 @@ int of_dma_configure(struct device *dev, struct device_node *np, bool force_dma) } /* - * Set default coherent_dma_mask to 32 bit. Drivers are expected to - * setup the correct supported mask. + * If @dev is expected to be DMA-capable then the bus code that created + * it should have initialised its dma_mask pointer by this point. For + * now, we'll continue the legacy behaviour of coercing it to the + * coherent mask if not, but we'll no longer do so quietly. */ - if (!dev->coherent_dma_mask) - dev->coherent_dma_mask = DMA_BIT_MASK(32); - /* - * Set it to coherent_dma_mask by default if the architecture - * code has not set it. - */ - if (!dev->dma_mask) + if (!dev->dma_mask) { + dev_warn(dev, "DMA mask not set\n"); dev->dma_mask = &dev->coherent_dma_mask; + } - if (!size) + if (!size && dev->coherent_dma_mask) size = max(dev->coherent_dma_mask, dev->coherent_dma_mask + 1); + else if (!size) + size = 1ULL << 32; dev->dma_pfn_offset = offset; |