  Using Lusztig's geometric classification, we find the reducibility points of
a standard module for the affine Hecke algebra, in the case when the inducing
data is generic. This recovers the known result of Muic-Shahidi for
representations of split p-adic groups with Iwahori-spherical Whittaker
vectors. We also give a necessary (insufficient) condition for reducibility in
the non-generic case.
