Ignore negative intensities for scrypt.
diff --git a/driver-opencl.c b/driver-opencl.c
index c578a98..e44faef 100644
--- a/driver-opencl.c
+++ b/driver-opencl.c
@@ -1020,7 +1020,12 @@ static void set_threads_hashes(unsigned int vectors, unsigned int *threads,
int64_t *hashes, size_t *globalThreads,
unsigned int minthreads, int intensity)
{
- *threads = 1 << ((opt_scrypt ? 0 : 15) + intensity);
+ if (opt_scrypt) {
+ if (intensity < 0)
+ intensity = 0;
+ *threads = 1 << intensity;
+ } else
+ *threads = 1 << (15 + intensity);
if (*threads < minthreads)
*threads = minthreads;
*globalThreads = *threads;