Hi !
So I see this construct:
if (test_and_set_bit(0, &chip->opened))
return -EBUSY;
.../...
return 0;
_error:
dprintk(1,"Error opening PCM!\n");
clear_bit(0, &chip->opened);
smp_mb__after_clear_bit();
return err;
So that's basically an attempt at doing a spinlock. The problem is your
barrier is wrong at the end. Better would be:
done:
smp_mb__before_clear_bit();
clear_bit(0, &chip->opened);
Though it's still less optimal that doing:
if (!spin_trylock(...))
goto bail;
.../...
done:
spin_unlock(...)
If you really want to stick to bitops, then you may want to look at
Nick's upcoming patches adding some bitops with appropriate lock
semantics.
Cheers,
Ben.
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
