Comment fixes.

ecc-eh-to-a.c

@@ -68,9 +68,10 @@ ecc_eh_to_a (const struct ecc_curve *ecc,
       /* Skip y coordinate */
       if (op > 1)
 	{
-	  /* Reduce modulo q. FIXME: Hardcoded for curve25519,
-	     duplicates end of ecc_25519_modq. FIXME: Is this needed
-	     at all? Full reduction mod p is maybe sufficient. */
+	  /* Reduce modulo q. Hardcoded for curve25519, duplicates end
+	     of ecc_25519_modq. FIXME: Is this needed at all? op > 0
+	     is only used by ecdsa code, and ecdsa on Edwards curves
+	     makes little sense and is is only used by tests. */
 	  unsigned shift;
 	  assert (ecc->p.bit_size == 255);
 	  shift = ecc->q.bit_size - 1 - GMP_NUMB_BITS * (ecc->p.size - 1);

ecc-internal.h

@@ -283,17 +283,16 @@ ecc_a_to_j (const struct ecc_curve *ecc,
 
 /* Converts a point P in jacobian coordinates into a point R in affine
    coordinates. If op == 1, produce x coordinate only. If op == 2,
-   produce the x coordiante only, and in also it modulo q. FIXME: For
-   the public interface, have separate for the three cases, and use
-   this flag argument only for the internal ecc->h_to_a function. */
+   produce the x coordinate only, and also reduce it modulo q. */
 void
 ecc_j_to_a (const struct ecc_curve *ecc,
 	    int op,
 	    mp_limb_t *r, const mp_limb_t *p,
 	    mp_limb_t *scratch);
 
-/* Converts a point P on an Edwards curve to affine coordinates on
-   the corresponding Montgomery curve. */
+/* Converts a point P in homogeneous coordinates on an Edwards curve
+   to affine coordinates. Meaning of op is the same as for
+   ecc_j_to_a. */
 void
 ecc_eh_to_a (const struct ecc_curve *ecc,
 	     int op,