2016-07-15 14:24 GMT+02:00 Wolfram Sang <wsa@xxxxxxxxxxxxx>: >> +/* >> + * 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. > While it's technically possible, it will never happen as long as write_timeout is set to some sensible value. Thanks, Bartosz -- To unsubscribe from this list: send the line "unsubscribe linux-i2c" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
