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From:   Zenghui Yu <yuzenghui@huawei.com>
To:     <linux-kernel@vger.kernel.org>, <iommu@lists.linux-foundation.org>,
        <hch@lst.de>, <m.szyprowski@samsung.com>, <robin.murphy@arm.com>
CC:     <wanghaibin.wang@huawei.com>, Zenghui Yu <yuzenghui@huawei.com>
Subject: [PATCH] dma-debug: Delete outdated comment of the hash function
Date:   Tue, 29 Dec 2020 21:40:06 +0800
Message-ID: <20201229134006.1691-1-yuzenghui@huawei.com>
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Precedence: bulk

We actually use dev_addr[26:13] as the index into dma_entry_hash. Given
that the code itself is clear enough, let's drop the hardcoded comment so
that we won't need to revisit it every time HASH_FN_{SHIFT,MASK} gets
updated.

Signed-off-by: Zenghui Yu <yuzenghui@huawei.com>
---
 kernel/dma/debug.c | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/kernel/dma/debug.c b/kernel/dma/debug.c
index 14de1271463f..d89341162d35 100644
--- a/kernel/dma/debug.c
+++ b/kernel/dma/debug.c
@@ -235,10 +235,7 @@ static bool driver_filter(struct device *dev)
  */
 static int hash_fn(struct dma_debug_entry *entry)
 {
-	/*
-	 * Hash function is based on the dma address.
-	 * We use bits 20-27 here as the index into the hash
-	 */
+	/* Hash function is based on the dma address. */
 	return (entry->dev_addr >> HASH_FN_SHIFT) & HASH_FN_MASK;
 }
 
-- 
2.19.1