linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Jisheng Zhang <Jisheng.Zhang@synaptics.com>
To: Evgeniy Didin <Evgeniy.Didin@synopsys.com>
Cc: <linux-mmc@vger.kernel.org>,
	Alexey Brodkin <Alexey.Brodkin@synopsys.com>,
	Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>,
	Douglas Anderson <dianders@chromium.org>,
	"Ulf Hansson" <ulf.hansson@linaro.org>,
	<linux-kernel@vger.kernel.org>,
	<linux-snps-arc@lists.infradead.org>, <stable@vger.kernel.org>,
	Vineet Gupta <Vineet.Gupta1@synopsys.com>
Subject: Re: [PATCH 0/2 v3] mmc: dw_mmc: Fix DTO/STO timeout overflow calculation
Date: Tue, 27 Feb 2018 11:02:45 +0800	[thread overview]
Message-ID: <20180227110245.6d78ff23@xhacker.debian> (raw)
In-Reply-To: <20180226143413.44134-1-Evgeniy.Didin@synopsys.com>

On Mon, 26 Feb 2018 17:34:11 +0300 Evgeniy Didin  wrote:

> For some 32-bit architectures calculation of DTO and STO timeout can be incorrect
> due to multiply overflow. Lets prevent this by casting multiply and result to u64.
> 
> Suggested by Jisheng Zhang.
> Switch DIV_ROUND_UP macro to DIV_ROUND_UP_ULL is not reasonable
> because overflow happens on multiply and DIV_ROUND_UP_ULL helps
> with sum overflow.

hmmm, I mean something as below:

-cto_ms = DIV_ROUND_UP(MSEC_PER_SEC * cto_clks * cto_div, host->bus_hz);
+cto_ms = DIV_ROUND_UP_ULL((u64)MSEC_PER_SEC * cto_clks * cto_div, host->bus_hz);

This could avoid build error in arm case.

> 
> ---
> Changes since v2:
> -add fix for cto_ms
> 
> Evgeniy Didin (2):
>   mmc: dw_mmc: Fix the DTO timeout overflow calculation for 32-bit
>     systems
>   mmc: dw_mmc: Fix the CTO overflow calculation for 32-bit systems

These two patches could be folded into one patch?

Thanks

      parent reply	other threads:[~2018-02-27  3:07 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-02-26 14:34 [PATCH 0/2 v3] mmc: dw_mmc: Fix DTO/STO timeout overflow calculation Evgeniy Didin
2018-02-26 14:34 ` [PATCH 1/2 v3] mmc: dw_mmc: Fix the DTO timeout overflow calculation for 32-bit systems Evgeniy Didin
2018-02-26 14:40   ` Andy Shevchenko
2018-02-27  1:14   ` Shawn Lin
2018-03-01  1:22   ` kbuild test robot
2018-02-26 14:34 ` [PATCH 2/2 v3] mmc: dw_mmc: Fix the CTO " Evgeniy Didin
2018-02-26 14:39   ` Andy Shevchenko
2018-02-26 15:14     ` Evgeniy Didin
2018-02-26 16:53       ` Andy Shevchenko
2018-02-26 17:14         ` Evgeniy Didin
2018-02-26 18:30           ` Andy Shevchenko
2018-02-26 20:27             ` Alexey Brodkin
2018-02-27  3:52               ` Jisheng Zhang
2018-02-27 10:49                 ` Andy Shevchenko
2018-02-27  3:02 ` Jisheng Zhang [this message]

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20180227110245.6d78ff23@xhacker.debian \
    --to=jisheng.zhang@synaptics.com \
    --cc=Alexey.Brodkin@synopsys.com \
    --cc=Eugeniy.Paltsev@synopsys.com \
    --cc=Evgeniy.Didin@synopsys.com \
    --cc=Vineet.Gupta1@synopsys.com \
    --cc=dianders@chromium.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mmc@vger.kernel.org \
    --cc=linux-snps-arc@lists.infradead.org \
    --cc=stable@vger.kernel.org \
    --cc=ulf.hansson@linaro.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).