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Date:   Sat, 20 Jun 2020 09:35:00 +0000
To:     Thomas Bogendoerfer <tsbogend@alpha.franken.de>
From:   Alexander Lobakin <alobakin@pm.me>
Cc:     Alexandre Belloni <alexandre.belloni@bootlin.com>,
        Paul Burton <paulburton@kernel.org>,
        Alexander Lobakin <alobakin@pm.me>, linux-mips@vger.kernel.org,
        linux-kernel@vger.kernel.org
Reply-To: Alexander Lobakin <alobakin@pm.me>
Subject: [PATCH mips-next 3/3] MIPS: checksum: fix sparse flooding on asm/checksum.h
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csum_fold() in MIPS' asm/checksum.h is another source of sparse flooding
when building different networking source code.
The thing is that only half of __wsum <--> u32 casts inside the funtion
is forced, which is insufficient.
Add all necessary forced typecasting to stop floods and simplify actual
bug hunting.

Signed-off-by: Alexander Lobakin <alobakin@pm.me>
---
 arch/mips/include/asm/checksum.h | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/mips/include/asm/checksum.h b/arch/mips/include/asm/check=
sum.h
index dcebaaf8c862..181f7d14efb9 100644
--- a/arch/mips/include/asm/checksum.h
+++ b/arch/mips/include/asm/checksum.h
@@ -113,9 +113,9 @@ static inline __sum16 csum_fold(__wsum csum)
 =09u32 sum =3D (__force u32)csum;
=20
 =09sum +=3D (sum << 16);
-=09csum =3D (sum < csum);
+=09csum =3D (__force __wsum)(sum < (__force u32)csum);
 =09sum >>=3D 16;
-=09sum +=3D csum;
+=09sum +=3D (__force u32)csum;
=20
 =09return (__force __sum16)~sum;
 }
--=20
2.27.0