[RFC AR6000 patch V2] Set hardware unavailable during wext_ioctl when the suspend or rfkill is send
Michael Trimarchi
trimarchi at gandalf.sssup.it
Tue Mar 31 08:47:04 CEST 2009
Hi,
Werner Almesberger wrote:
> Michael Trimarchi wrote:
>
>> ->ioctl_start ..... by a process, your lock is not acquire
>> <--- in the middle you acquire the hardware lock and don't made the hw_unvalaible
>> ---> release the lock at the end
>> -> call ioctl_wext crash
>>
>
>
> What I mean is something like this:
>
> ar6000_avail_ev()
> {
> up_write(&sem);
> }
>
> ar6000_unavail_ev()
> {
> down_write(&sem);
> }
>
> ar6000_do_ioctl()
> {
> ...
> }
>
> ar6000_ioctl()
> {
> if (!down_read_trylock(&sem))
> return -EIO;
> ar6000_do_ioctl();
> up_read(&sem);
> }
>
> If the unavailability event arrives while we're still in the ioctl,
> the down_write just blocks until the ioctl ends and releases the
> read lock.
>
> - Werner
>
>
Ok, it's the same with one lock. Sorry, for the delay, seems to be a
better solution.
Michael
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