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From: Alessandro Rubini <rubini-list@gnudd.com>
To: u-boot@lists.denx.de
Subject: [U-Boot] PATCH mtd CFI flash: timeout calculation underflow if	imprecise 1kHz timer: fix
Date: Thu, 6 Aug 2009 12:12:41 +0200	[thread overview]
Message-ID: <20090806101241.GA23106@mail.gnudd.com> (raw)
In-Reply-To: <4A7AA72C.8010704@imagos.it>

> With old configuration it could happen tout=0 if CONFIG_SYS_HZ<1000
> solved using an unsigned long long

I had the same problem with an ancient version of a vendor-ported u-boot. There
my CFG_HZ was 100, so the timeout was 0.

I used this, which avoids the preprocessor conditional. Since the HZ value
is a compile-time constant, the compiler chooses the if or else branch and doesn't
spit a run-time conditional.2

        if (CFG_HZ > 100000)
                tout *= CFG_HZ/1000;  /* for a big HZ, avoid overflow */
        else
                tout = tout * CFG_HZ / 1000 + 1;


/alessandro

  parent reply	other threads:[~2009-08-06 10:12 UTC|newest]

Thread overview: 28+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-08-06  9:49 [U-Boot] PATCH mtd CFI flash: timeout calculation underflow if imprecise 1kHz timer: fix Renato Andreola
2009-08-06 10:07 ` Wolfgang Denk
2009-08-06 10:12 ` Alessandro Rubini [this message]
     [not found]   ` <4A7AB614.2020509@imagos.it>
2009-08-06 11:40     ` Wolfgang Denk
  -- strict thread matches above, loose matches on Subject: below --
2009-08-24  8:32 Renato Andreola
2009-08-25 13:25 ` Shinya Kuribayashi
2009-08-25 15:01   ` Renato Andreola
2009-08-25 15:39 ` Stefan Roese
2009-08-25 15:44   ` Stefan Roese
2009-11-22 21:09 ` Wolfgang Denk
2009-11-23  8:51   ` Renato Andreola
2009-11-23 19:36     ` Wolfgang Denk
2009-08-06 16:08 Renato Andreola
2009-08-06 13:09 Renato Andreola
2009-08-06 13:22 ` Wolfgang Denk
2009-08-06 13:31   ` Alessandro Rubini
2009-08-06 14:19     ` Wolfgang Denk
2009-08-06 20:26 ` Jean-Christophe PLAGNIOL-VILLARD
2009-08-06 20:53   ` Wolfgang Denk
2009-08-06 21:01     ` Wolfgang Denk
2009-08-06 21:15     ` Jean-Christophe PLAGNIOL-VILLARD
2009-08-06 21:35       ` Wolfgang Denk
2009-08-07  8:15     ` Renato Andreola
2009-08-07  9:16       ` Wolfgang Denk
2009-08-07 12:14         ` Renato Andreola
2009-08-09 21:13           ` Wolfgang Denk
2009-04-10 12:28 Renato Andreola
2009-04-13 22:09 ` Jean-Christophe PLAGNIOL-VILLARD

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