From 2d6cb431e328c8cd57b03e7272dc750c9ace08ed Mon Sep 17 00:00:00 2001
From: erhankur <erhankurubas@gmail.com>
Date: Sat, 10 Aug 2024 12:43:34 +0200
Subject: [PATCH] fix(jtag): flush previous gdb responses before the first gdb
 command

---
 .../pytest_embedded_jtag/gdb.py               | 37 ++++++++++---------
 1 file changed, 20 insertions(+), 17 deletions(-)

diff --git a/pytest-embedded-jtag/pytest_embedded_jtag/gdb.py b/pytest-embedded-jtag/pytest_embedded_jtag/gdb.py
index 756875c8..0f5e6b64 100644
--- a/pytest-embedded-jtag/pytest_embedded_jtag/gdb.py
+++ b/pytest-embedded-jtag/pytest_embedded_jtag/gdb.py
@@ -20,36 +20,39 @@ def __init__(self, gdb_prog_path: Optional[str] = None, gdb_cli_args: Optional[s
         gdb_prog_path = gdb_prog_path or self.GDB_PROG_PATH
         gdb_cli_args = shlex.split(gdb_cli_args or self.GDB_DEFAULT_ARGS)
 
-        self._gdb_first_prompt_matched = False
+        self._gdb_first_write = True
 
         super().__init__(cmd=[gdb_prog_path, *gdb_cli_args], **kwargs)
 
     def write(self, s: AnyStr, non_blocking: bool = False, timeout: float = 30) -> Optional[str]:
-        super().write(s)
-        _buffer = ''
-        _t_start = time.time()
-
         with open(self._logfile) as fr:
+            if self._gdb_first_write:
+                # Discard all queued responses before the first write
+                _ = fr.readlines()
+                self._logfile_offset = fr.tell()
+                self._gdb_first_write = False
+
+            super().write(s)
+
+            if non_blocking:
+                logging.debug('non-blocking write...')
+                return None
+
+            _buffer = ''
+            _t_start = time.time()
             fr.seek(self._logfile_offset)
             while True:
                 line = fr.readline()
-                _t_now = time.time()
-                if non_blocking:
-                    logging.debug('non-blocking write...')
-                    return None
-
-                if (_t_now - _t_start) >= timeout:
-                    logging.debug(f'current buffer: {_buffer}')
-                    raise ValueError(f'gdb no response after {timeout} seconds')
-
                 if line:
                     _buffer += line
                     if self._GDB_RESPONSE_FINISHED_RE.match(line):
-                        if not self._gdb_first_prompt_matched:
-                            self._gdb_first_prompt_matched = True
-                            continue
                         break
 
+                _t_now = time.time()
+                if (_t_now - _t_start) >= timeout:
+                    logging.debug(f'current buffer: {_buffer}')
+                    raise ValueError(f'gdb no response after {timeout} seconds')
+
             self._logfile_offset = fr.tell()
 
         logging.debug(f'{self.SOURCE} <-: {_buffer}')