SMEM-P: debug with linear index pattern m*128+n

dsv4/kernels/attention/fmha.py

@@ -359,10 +359,11 @@ class FmhaKernel:
                             n2 = n // 64
                             pv_coord = ((m, n0), 0, (n1, n2), 0)
                             
-                            # DEBUG: Write simple test pattern (k+j)*0.01
-                            # This helps verify coordinate mapping
-                            # k and j are loop indices (0-31, 0-3)
-                            pattern_val = Float32(k + j) * Float32(0.01)
+                            # DEBUG: Write linear index as value: m*128 + n
+                            # This uniquely identifies each position
+                            linear_idx = m * 128 + n
+                            # Convert to Float32 (values 0-16383)
+                            pattern_val = Float32(linear_idx)
                             p_val_bf16 = pattern_val.to(self.q_dtype)
                             # Original: p_val_bf16 = tTMEM_LOADrS_frg[k, j].to(self.q_dtype)
                             sP[pv_coord] = p_val_bf16