Am 14.12.2012 15:15, schrieb Alexander Holler:
Am 14.12.2012 14:08, schrieb Alexander Holler:
Am 14.12.2012 10:42, schrieb Lars-Peter Clausen:
And another thing I've overlooked before:
wait_for_completion_interruptible_timeout can either return a positive
number when the completion was completed, 0 in case of an timeout, or a
negative error code in case it was interrupted. You need to handle all
three. E.g. something like this.
ret = wait_for_completion_interruptible_timeout(...)
if (ret == 0)
return -EIO;
if (ret < 0)
return ret
Hmpf, the only working approach to use some in kernel functions really
is to the read source yourself and don't trust anything else. :/
Anyway, my approach doesn't work as it introduces a race condition:
/* get a report with all values through requesting one value */
sensor_hub_input_attr_get_raw_value(...)
/* race if this task goes to slepp and the values were
received before it could call the below wait...
/* wait for all values (event) */
if (!wait_for_completion_interruptible_timeout(...))
I'll have to look for a mechanism how to avoid that. So v5 might need
some time.
Sorry for the noise. That INIT_COMPLETION() before the sensor...() does
exactly that. So it's enough if I handle the different return situations
of wait_for...().
I will just use if(wait...()<=0) return -EIO.
Regards,
Alexander
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