From: "Arnd Bergmann" <arnd@arndb.de>
To: "Zhihao Cheng" <chengzhihao1@huawei.com>,
"Arnd Bergmann" <arnd@kernel.org>,
"Richard Weinberger" <richard@nod.at>,
"Miquel Raynal" <miquel.raynal@bootlin.com>,
"Vignesh Raghavendra" <vigneshr@ti.com>,
"Daniel Golle" <daniel@makrotopia.org>
Cc: linux-mtd@lists.infradead.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] mtd: ubi: avoid expensive do_div() on 32-bit machines
Date: Wed, 13 Mar 2024 14:51:14 +0100 [thread overview]
Message-ID: <1ee86ea9-fa91-4795-b5f8-2e57609ae65e@app.fastmail.com> (raw)
In-Reply-To: <ecc5d070-a773-1180-b50c-59088b23695e@huawei.com>
On Wed, Mar 13, 2024, at 14:43, Zhihao Cheng wrote:
> 在 2024/3/13 21:39, Arnd Bergmann 写道:
>
>>> Thanks for explaination, which means that do_div is used for 64-bit
>>> division to solve the link failure caused by missed libgcc. Since
>>> parameter 'from' is u32, there is no need to invoke do_div on a 32-bit
>>> platform, you just want to stop the wasting behavior on a 32-bit
>>> platform. Do I understand right?
>>
> How do you find it? I mean there are so many types and many do_div
> callers, do you have a static check tool?
I had a local fix with the same effect that I applied when
the code originally broke, but had not gotten around to
sending my fix.
After b8a77b9a5f9c ("mtd: ubi: fix NVMEM over UBI volumes on
32-bit systems") introduced a different workaround, I got the
link error because I had removed the do_div().
Arnd
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next prev parent reply other threads:[~2024-03-13 13:51 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-03-13 8:46 [PATCH] mtd: ubi: avoid expensive do_div() on 32-bit machines Arnd Bergmann
2024-03-13 11:29 ` Zhihao Cheng
2024-03-13 11:53 ` Arnd Bergmann
2024-03-13 12:10 ` Zhihao Cheng
2024-03-13 12:21 ` Arnd Bergmann
2024-03-13 13:29 ` Zhihao Cheng
2024-03-13 13:39 ` Arnd Bergmann
2024-03-13 13:43 ` Zhihao Cheng
2024-03-13 13:51 ` Arnd Bergmann [this message]
2024-03-13 13:41 ` Zhihao Cheng
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