usb_power_delivery: enforce check order for start-of-packet sequences

[libsigrokdecode.git] / decoders / usb_power_delivery / pd.py

diff --git a/decoders/usb_power_delivery/pd.py b/decoders/usb_power_delivery/pd.py
index de6f39418c6930f647384b75186a0a5382ddfb37..c182498c025f5535cf758013699d35694485e2ab 100644 (file)
--- a/decoders/usb_power_delivery/pd.py
+++ b/decoders/usb_power_delivery/pd.py
@@ -101,14 +101,23 @@ EOP = 0x16
 SYNC_CODES = [SYNC1, SYNC2, SYNC3]
 HRST_CODES = [RST1, RST1, RST1, RST2]
 
+SOP_SEQUENCES = [
+    (SYNC1, SYNC1, SYNC1, SYNC2),
+    (SYNC1, SYNC1, SYNC3, SYNC3),
+    (SYNC1, SYNC3, SYNC1, SYNC3),
+    (SYNC1, RST2,  RST2,  SYNC3),
+    (SYNC1, RST2,  SYNC3, SYNC2),
+    (RST1,  SYNC1, RST1,  SYNC3),
+    (RST1,  RST1,  RST1,   RST2),
+]
 START_OF_PACKETS = {
-    (SYNC1, SYNC1, SYNC1, SYNC2): 'SOP',
-    (SYNC1, SYNC1, SYNC3, SYNC3): "SOP'",
-    (SYNC1, SYNC3, SYNC1, SYNC3): 'SOP"',
-    (SYNC1, RST2,  RST2,  SYNC3): "SOP' Debug",
-    (SYNC1, RST2,  SYNC3, SYNC2): 'SOP" Debug',
-    (RST1,  SYNC1, RST1,  SYNC3): 'Cable Reset',
-    (RST1,  RST1,  RST1,   RST2): 'Hard Reset',
+    SOP_SEQUENCES[0]: 'SOP',
+    SOP_SEQUENCES[1]: "SOP'",
+    SOP_SEQUENCES[2]: 'SOP"',
+    SOP_SEQUENCES[3]: "SOP' Debug",
+    SOP_SEQUENCES[4]: 'SOP" Debug',
+    SOP_SEQUENCES[5]: 'Cable Reset',
+    SOP_SEQUENCES[6]: 'Hard Reset',
 }
 
 SYM_NAME = [
@@ -403,7 +412,7 @@ class Decoder(srd.Decoder):
     def find_corrupted_sop(self, k):
         # Start of packet are valid even if they have only 3 correct symbols
         # out of 4.
-        for seq in START_OF_PACKETS.keys():
+        for seq in SOP_SEQUENCES:
             if [k[i] == seq[i] for i in range(len(k))].count(True) >= 3:
                 return START_OF_PACKETS[seq]
         return None