diff mbox series

[v7,1/3] phy: mediatek: remove temporary variable @mask_

Message ID 20230118084343.26913-1-chunfeng.yun@mediatek.com (mailing list archive)
State New, archived
Headers show
Series [v7,1/3] phy: mediatek: remove temporary variable @mask_ | expand

Commit Message

Chunfeng Yun Jan. 18, 2023, 8:43 a.m. UTC
Remove the temporary @mask_, this may cause build warning when use clang
compiler for powerpc, but can't reproduce it when compile for arm64.
the build warning is caused by:

"warning: result of comparison of constant 18446744073709551615 with
expression of type (aka 'unsigned long') is always false
[-Wtautological-constant-out-of-range-compare]"

More information provided in below lore link.

After removing @mask_, there is a "CHECK:MACRO_ARG_REUSE" when run
checkpatch.pl, but due to @mask is constant, no reuse problem will happen.

Link: https://lore.kernel.org/lkml/202212160357.jJuesD8n-lkp@intel.com/t/
Fixes: 84513eccd678 ("phy: mediatek: fix build warning of FIELD_PREP()")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
---
v7: modify title suggested by Vinod,
    modify commit message and add link tag suggested by Nick

v6: modify the title
v5: no changes
v4 new patch, I'm not sure it can fix build warning, due to I don't cross compile
    it for powerpc using clang in office.
---
 drivers/phy/mediatek/phy-mtk-io.h | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

Comments

AngeloGioacchino Del Regno Jan. 18, 2023, 12:29 p.m. UTC | #1
Il 18/01/23 09:43, Chunfeng Yun ha scritto:
> Remove the temporary @mask_, this may cause build warning when use clang
> compiler for powerpc, but can't reproduce it when compile for arm64.
> the build warning is caused by:
> 
> "warning: result of comparison of constant 18446744073709551615 with
> expression of type (aka 'unsigned long') is always false
> [-Wtautological-constant-out-of-range-compare]"
> 
> More information provided in below lore link.
> 
> After removing @mask_, there is a "CHECK:MACRO_ARG_REUSE" when run
> checkpatch.pl, but due to @mask is constant, no reuse problem will happen.
> 
> Link: https://lore.kernel.org/lkml/202212160357.jJuesD8n-lkp@intel.com/t/
> Fixes: 84513eccd678 ("phy: mediatek: fix build warning of FIELD_PREP()")
> Reported-by: kernel test robot <lkp@intel.com>
> Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com>

Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Vinod Koul Feb. 2, 2023, 1:05 p.m. UTC | #2
On 18-01-23, 16:43, Chunfeng Yun wrote:
> Remove the temporary @mask_, this may cause build warning when use clang
> compiler for powerpc, but can't reproduce it when compile for arm64.
> the build warning is caused by:
> 
> "warning: result of comparison of constant 18446744073709551615 with
> expression of type (aka 'unsigned long') is always false
> [-Wtautological-constant-out-of-range-compare]"
> 
> More information provided in below lore link.
> 
> After removing @mask_, there is a "CHECK:MACRO_ARG_REUSE" when run
> checkpatch.pl, but due to @mask is constant, no reuse problem will happen.

Applied, thanks
diff mbox series

Patch

diff --git a/drivers/phy/mediatek/phy-mtk-io.h b/drivers/phy/mediatek/phy-mtk-io.h
index d20ad5e5be81..58f06db822cb 100644
--- a/drivers/phy/mediatek/phy-mtk-io.h
+++ b/drivers/phy/mediatek/phy-mtk-io.h
@@ -39,8 +39,8 @@  static inline void mtk_phy_update_bits(void __iomem *reg, u32 mask, u32 val)
 /* field @mask shall be constant and continuous */
 #define mtk_phy_update_field(reg, mask, val) \
 ({ \
-	typeof(mask) mask_ = (mask);	\
-	mtk_phy_update_bits(reg, mask_, FIELD_PREP(mask_, val)); \
+	BUILD_BUG_ON_MSG(!__builtin_constant_p(mask), "mask is not constant"); \
+	mtk_phy_update_bits(reg, mask, FIELD_PREP(mask, val)); \
 })
 
 #endif