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

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>

diff --git a/kernel/dma/direct.c b/kernel/dma/direct.c
index 974e96a1de4485f1fbce42792d1f2df51c290b9a..795c9b095d7573a79df1d4eeef00a10dca6a2ee4 100644 (file)
--- a/kernel/dma/direct.c
+++ b/kernel/dma/direct.c
@@ -47,9 +47,6 @@ 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;
 }