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From:   Anders Roxell <anders.roxell@linaro.org>
To:     vkoul@kernel.org, dan.j.williams@intel.com
Cc:     dmaengine@vger.kernel.org, linux-kernel@vger.kernel.org,
        Anders Roxell <anders.roxell@linaro.org>
Subject: [PATCH] dma: ixm-dma: fix warning comparison of distinct pointer types
Date:   Thu, 10 Jan 2019 12:15:35 +0100
Message-Id: <20190110111535.11235-1-anders.roxell@linaro.org>
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Sender: linux-kernel-owner@vger.kernel.org
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The warning got introduced by commit 930507c18304 ("arm64: add basic
Kconfig symbols for i.MX8"). Since it got enabled for arm64. The warning
haven't been seen before since size_t was 'unsigned int' when built on
arm32.

../drivers/dma/imx-dma.c: In function ‘imxdma_sg_next’:
../include/linux/kernel.h:846:29: warning: comparison of distinct pointer types lacks a cast
   (!!(sizeof((typeof(x) *)1 == (typeof(y) *)1)))
                             ^~
../include/linux/kernel.h:860:4: note: in expansion of macro ‘__typecheck’
   (__typecheck(x, y) && __no_side_effects(x, y))
    ^~~~~~~~~~~
../include/linux/kernel.h:870:24: note: in expansion of macro ‘__safe_cmp’
  __builtin_choose_expr(__safe_cmp(x, y), \
                        ^~~~~~~~~~
../include/linux/kernel.h:879:19: note: in expansion of macro ‘__careful_cmp’
 #define min(x, y) __careful_cmp(x, y, <)
                   ^~~~~~~~~~~~~
../drivers/dma/imx-dma.c:288:8: note: in expansion of macro ‘min’
  now = min(d->len, sg_dma_len(sg));
        ^~~

Rework so that we use min_t and pass in the size_t that returns the
minimum of two values, using the specified type.

Signed-off-by: Anders Roxell <anders.roxell@linaro.org>
---
 drivers/dma/imx-dma.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/dma/imx-dma.c b/drivers/dma/imx-dma.c
index c2fff3f6c9ca..fa3ef43fe314 100644
--- a/drivers/dma/imx-dma.c
+++ b/drivers/dma/imx-dma.c
@@ -285,7 +285,7 @@ static inline int imxdma_sg_next(struct imxdma_desc *d)
 	struct scatterlist *sg = d->sg;
 	unsigned long now;
 
-	now = min(d->len, sg_dma_len(sg));
+	now = min_t(size_t, d->len, sg_dma_len(sg));
 	if (d->len != IMX_DMA_LENGTH_LOOP)
 		d->len -= now;
 
-- 
2.19.2