Re: [RESEND PATCH 05/14] eeprom: at24: hide the read/write loop behind a macro

From	Wolfram Sang <wsa@the-dreams.de>
Newsgroups	linux.kernel
Subject	Re: [RESEND PATCH 05/14] eeprom: at24: hide the read/write loop behind a macro
Date	2016-07-15 14:30 +0200
Message-ID	<rVapH-6QL-9@gated-at.bofh.it> (permalink)
References	<rGYoq-2vy-7@gated-at.bofh.it> <rGYoq-2vy-21@gated-at.bofh.it>
Organization	linux.* mail to news gateway

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> +/*
> + * Both reads and writes fail if the previous write didn't complete yet. This
> + * macro loops a few times waiting at least long enough for one entire page
> + * write to work.
> + *
> + * It takes two parameters: a variable in which the future timeout in jiffies
> + * will be stored and a temporary variable holding the time of the last
> + * iteration of processing the request. Both should be unsigned integers
> + * holding at least 32 bits.
> + */
> +#define loop_until_timeout(tout, op_time)				\
> +	for (tout = jiffies + msecs_to_jiffies(write_timeout),		\
> +		op_time = jiffies;					\
> +	     time_before(op_time, tout);				\
> +	     usleep_range(1000, 1500), op_time = jiffies)

There is one subtle change coming with this change: the do-while loop is
guaranteed to run at least once while the for-loop doesn't.

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Re: [RESEND PATCH 05/14] eeprom: at24: hide the read/write loop  behind a macro Wolfram Sang <wsa@the-dreams.de> - 2016-07-15 14:30 +0200
  Re: [RESEND PATCH 05/14] eeprom: at24: hide the read/write loop  behind a macro Bartosz Golaszewski <bgolaszewski@baylibre.com> - 2016-07-15 15:00 +0200
    Re: [RESEND PATCH 05/14] eeprom: at24: hide the read/write loop  behind a macro Wolfram Sang <wsa@the-dreams.de> - 2016-07-15 17:10 +0200
      Re: [RESEND PATCH 05/14] eeprom: at24: hide the read/write loop  behind a macro Wolfram Sang <wsa@the-dreams.de> - 2016-07-16 07:00 +0200
        Re: [RESEND PATCH 05/14] eeprom: at24: hide the read/write loop  behind a macro Bartosz Golaszewski <bgolaszewski@baylibre.com> - 2016-07-16 21:30 +0200
          Re: [RESEND PATCH 05/14] eeprom: at24: hide the read/write loop  behind a macro Wolfram Sang <wsa@the-dreams.de> - 2016-07-17 20:10 +0200

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