dma-direct: don't truncate dma_required_mask to bus addressing capabilities

[ Upstream commit d8ad55538abe443919e20e0bb996561bca9cad84 ]

The dma required_mask needs to reflect the actual addressing capabilities
needed to handle the whole system RAM. When truncated down to the bus
addressing capabilities dma_addressing_limited() will incorrectly signal
no limitations for devices which are restricted by the bus_dma_mask.

Fixes: b4ebe6063204 (dma-direct: implement complete bus_dma_mask handling)
Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Tested-by: Atish Patra <atish.patra@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/kernel/dma/direct.c b/kernel/dma/direct.c
index 2c2772e9702ab4748e6ef6f18835cdfedc185310..9912be7a970dec7f48049fb4a78e874b2ad90fe3 100644 (file)
--- a/kernel/dma/direct.c
+++ b/kernel/dma/direct.c
@@ -55,9 +55,6 @@ u64 dma_direct_get_required_mask(struct device *dev)
 {
        u64 max_dma = phys_to_dma_direct(dev, (max_pfn - 1) << PAGE_SHIFT);
 
-       if (dev->bus_dma_mask && dev->bus_dma_mask < max_dma)
-               max_dma = dev->bus_dma_mask;
-
        return (1ULL << (fls64(max_dma) - 1)) * 2 - 1;
 }