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| author | Bartosz Golaszewski <bgolaszewski@baylibre.com> | 2016-07-17 20:40:06 +0200 |
|---|---|---|
| committer | Wolfram Sang <wsa@the-dreams.de> | 2016-07-18 20:07:54 +0200 |
| commit | 24da3cc0e25f48e12656226e5ed313573a3b443f (patch) | |
| tree | 5ad5a9441d18e625b54678481c3ad80740c9d7d2 /drivers/misc | |
| parent | 0b813658c11532be90cbf5f579a8ba45a8cc9dbf (diff) | |
| download | linux-24da3cc0e25f48e12656226e5ed313573a3b443f.tar.bz2 | |
eeprom: at24: tweak the loop_until_timeout() macro
loop_until_timeout() replaced a do {} while loop in the at24 driver
with a for loop which, under certain circumstances (such as heavy load
or low value of the write_timeout argument), can lead to the code in
the loop never being executed.
Make sure that at least one iteration of the code enclosed within
loop_until_timeout() is always executed.
Suggested-by: Wolfram Sang <wsa@the-dreams.de>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Diffstat (limited to 'drivers/misc')
| -rw-r--r-- | drivers/misc/eeprom/at24.c | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/drivers/misc/eeprom/at24.c b/drivers/misc/eeprom/at24.c index 04e91e331fc5..3cdf8e1ca0ad 100644 --- a/drivers/misc/eeprom/at24.c +++ b/drivers/misc/eeprom/at24.c @@ -116,7 +116,8 @@ MODULE_PARM_DESC(write_timeout, "Time (in ms) to try writes (default 25)"); /* * 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. + * write to work while making sure that at least one iteration is run before + * checking the break condition. * * 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 @@ -124,9 +125,8 @@ MODULE_PARM_DESC(write_timeout, "Time (in ms) to try writes (default 25)"); * 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); \ + for (tout = jiffies + msecs_to_jiffies(write_timeout), op_time = 0; \ + op_time ? time_before(op_time, tout) : true; \ usleep_range(1000, 1500), op_time = jiffies) static const struct i2c_device_id at24_ids[] = { |