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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Lucas Stach <l.stach@pengutronix.de>,
        Atish Patra <atish.patra@wdc.com>,
        Christoph Hellwig <hch@lst.de>, Sasha Levin <sashal@kernel.org>
Subject: [PATCH 5.2 025/143] dma-direct: dont truncate dma_required_mask to bus addressing capabilities
Date:   Wed,  4 Sep 2019 19:52:48 +0200
Message-Id: <20190904175315.051650883@linuxfoundation.org>
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[ 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>
---
 kernel/dma/direct.c | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/kernel/dma/direct.c b/kernel/dma/direct.c
index 2c2772e9702ab..9912be7a970de 100644
--- 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;
 }
 
-- 
2.20.1