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coredevice/comm_serial: give up on garbage received after baudrate change

This commit is contained in:
Sebastien Bourdeauducq 2014-12-02 16:04:41 +08:00
parent cad5933709
commit 83d3b97b23
1 changed files with 8 additions and 4 deletions
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12
artiq/coredevice/comm_serial.py
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@ -88,16 +88,20 @@ class Comm:
_write_exactly(self.port, struct.pack( _write_exactly(self.port, struct.pack(
">lbl", 0x5a5a5a5a, _H2DMsgType.SET_BAUD_RATE.value, baud)) ">lbl", 0x5a5a5a5a, _H2DMsgType.SET_BAUD_RATE.value, baud))
handshake = 0 handshake = 0
fails = 0
while handshake < 4: while handshake < 4:
recv = struct.unpack( (recv, ) = struct.unpack("B", _read_exactly(self.port, 1))
"B", _read_exactly(self.port, 1)) if recv == 0x5a:
if recv[0] == 0x5a:
handshake += 1 handshake += 1
else: else:
# FIXME: when loading immediately after a board reset, # FIXME: when loading immediately after a board reset,
# we erroneously get some zeros back. # we erroneously get some zeros back.
logger.warning("unexpected sync character: {:02x}".format(int(recv[0]))) logger.warning("unexpected sync character: {:02x}".format(int(recv)))
handshake = 0 handshake = 0
if recv != 0:
fails += 1
if fails > 3:
raise IOError("Baudrate ack failed")
self.set_baud(baud) self.set_baud(baud)
logger.debug("synchronized") logger.debug("synchronized")