debug: debug_stream: Access debug slot directly using cavstool.py

Access debug slot directly using cavstool.py, by specifying the debug
slot number where the debug_stream data is transferred.

Adds one command line parameter for selecting the debug slot directly,
adds an alternative mainloop for polling the slot through cavstool.py
direct access, and relaxes some often occurring warning print. The
warning prints happen when the FW boots and the cavstool code wakes up
before the init code has initialized the slot.

Signed-off-by: Jyri Sarha <[email protected]>

tools/debug_stream/debug_stream.py

@@ -286,7 +286,7 @@ def catch_up(self, slot):
         self.decode_past_records(slot, circ.w_ptr, circ.next_seqno)
         self.prev_w_ptr = circ.w_ptr
         self.prev_seqno = circ.next_seqno - 1
-        logging.info("seqno %u w_ptr %u", self.prev_seqno, self.prev_w_ptr)
+        logging.debug("seqno %u w_ptr %u", self.prev_seqno, self.prev_w_ptr)
 
     def decode_past_records(self, slot, pos, seqno):
         """
@@ -393,6 +393,12 @@ def update_slot(self):
         self.file.seek(0)
         self.slot = self.file.read(self.file_size)
 
+    def set_slot(self, buf):
+        """
+        Update slot contents
+        """
+        self.slot = buf
+
     def get_descriptors(self):
         """
         Read the core specific descriptors and initialize core
@@ -403,7 +409,7 @@ def get_descriptors(self):
             return False
         hdr = ctypes.cast(self.slot, ctypes.POINTER(DebugStreamSlotHdr))
         if hdr.contents.hdr.magic != DEBUG_STREAM_PAYLOAD_MAGIC:
-            logging.warning("Debug Slot has bad magic 0x%08x", hdr.contents.hdr.magic)
+            logging.info("Debug Slot has bad magic 0x%08x", hdr.contents.hdr.magic)
             return False
         num_sections = hdr.contents.num_sections
         if num_sections == len(self.descs):
@@ -473,6 +479,32 @@ def reset(self):
         self.file = None
         self.slot = None
 
+def cavstool_main_loop(my_args):
+    global hda, sd, dsp, hda_ostream_id, hda_streams, args
+    import cavstool
+    try:
+        (hda, sd, dsp, hda_ostream_id) = cavstool.map_regs(True)
+    except Exception as e:
+        logging.error("Could not map device in sysfs; run as root?")
+        logging.error(e)
+        sys.exit(1)
+
+    decoder = DebugStreamDecoder()
+    while True:
+        if not cavstool.fw_is_alive_dsp(dsp):
+            cavstool.wait_fw_entered_dsp(dsp, timeout_s=None)
+        try:
+            offset = cavstool.debug_slot_offset(my_args.direct_access_slot);
+            buf = cavstool.win_read(offset, 0, 4096)
+            decoder.set_slot(buf)
+            if not decoder.get_descriptors():
+                continue
+            decoder.catch_up_all()
+            if decoder.poll():
+                time.sleep(my_args.update_interval)
+        except:
+            logging.error("win_read() failed")
+            continue
 
 def main_f(my_args):
     """
@@ -483,6 +515,8 @@ def main_f(my_args):
     about the host CPU load. That is why there where no synchronous mechanism
     done and the host simply polls for new records.
     """
+    if my_args.direct_access_slot >= 0:
+	    return cavstool_main_loop(my_args)
     decoder = DebugStreamDecoder()
     prev_error = None
     while True:
@@ -527,6 +561,13 @@ def parse_params():
         help="File to read the DebugStream data from, default /sys/kernel/debug/sof/debug_stream",
         default="/sys/kernel/debug/sof/debug_stream",
     )
+    parser.add_argument(
+        "-c",
+        "--direct-access-slot",
+        help="Access specified debug window slot directly, no need for debugfs file",
+        type=int,
+        default=-1,
+    )
     parsed_args = parser.parse_args()
     return parsed_args