From: David Laight <David.Laight@ACULAB.COM>
To: "'15330273260@189.cn'" <15330273260@189.cn>,
Jani Nikula <jani.nikula@linux.intel.com>,
Sui Jingfeng <suijingfeng@loongson.cn>, Li Yi <liyi@loongson.cn>
Cc: Thomas Zimmermann <tzimmermann@suse.de>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"dri-devel@lists.freedesktop.org"
<dri-devel@lists.freedesktop.org>,
"loongson-kernel@lists.loongnix.cn"
<loongson-kernel@lists.loongnix.cn>
Subject: RE: [PATCH] drm/drm_vblank.c: avoid unsigned int to signed int cast
Date: Tue, 23 May 2023 08:50:30 +0000 [thread overview]
Message-ID: <e5effc4568034489acf2f4d4dad6eba9@AcuMS.aculab.com> (raw)
In-Reply-To: <4c9c0897-5e3a-1469-3d87-ff7723ac160c@189.cn>
From: 15330273260@189.cn <15330273260@189.cn>
> Sent: 23 May 2023 05:27
>
> On 2023/5/22 19:29, Jani Nikula wrote:
> > In general, do not use unsigned types in arithmethic to avoid negative
> > values, because most people will be tripped over by integer promotion
> > rules, and you'll get negative values anyway.
>
>
> Here I'm sure about this,
>
> but there are plenty unsigned types arithmetic in the kernel.
The real problem is (attempted) arithmetic on types smaller than int.
Regardless of whether they are signed or unsigned.
David
-
Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK
Registration No: 1397386 (Wales)
next prev parent reply other threads:[~2023-05-23 8:50 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-05-16 17:30 Sui Jingfeng
2023-05-17 10:59 ` David Laight
2023-05-17 18:08 ` Sui Jingfeng
2023-05-22 11:29 ` Jani Nikula
2023-05-22 11:55 ` Sui Jingfeng
2023-05-22 12:07 ` David Laight
2023-05-22 12:13 ` Jani Nikula
2023-05-22 12:53 ` Sui Jingfeng
2023-05-22 15:01 ` Jani Nikula
2023-05-23 3:55 ` Sui Jingfeng
2023-05-23 4:26 ` Sui Jingfeng
2023-05-23 8:12 ` Sui Jingfeng
2023-05-23 8:50 ` David Laight [this message]
2023-05-23 9:55 ` Sui Jingfeng
-- strict thread matches above, loose matches on Subject: below --
2023-05-16 16:59 Sui Jingfeng
2023-05-16 17:06 ` Thomas Zimmermann
2023-05-16 17:13 ` Sui Jingfeng
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