/bin/wifi: robustify Quantenna device detection.
Detect Quantenna device without actually executing the QCSAPI and move
detection out of module load time. Instead, check if the qdpc-host
module is loaded and the QCSAPI binaries exist, and memoize the result.
Change-Id: If2ff5d7e7035ca90d23e721f3ad820e5cd229199
diff --git a/wifi/quantenna.py b/wifi/quantenna.py
index bee478f..0bed0c8 100755
--- a/wifi/quantenna.py
+++ b/wifi/quantenna.py
@@ -9,27 +9,23 @@
import utils
-# Detect Quantenna device.
-#
-# qcsapi_pcie_static runs on PCIe hosts, e.g. GFRG250.
-# call_qcsapi runs on the LHOST, e.g. GFEX250.
-#
-# When called without arguments, qcsapi_pcie_static checks for a Quantenna
-# device without sending any RPCs. Both programs return 234 only if a Quantenna
-# device is present.
-_QCSAPI = None
-for qcsapi in ['qcsapi_pcie_static', 'call_qcsapi']:
- with open(os.devnull, 'w') as devnull:
- try:
- if subprocess.call([qcsapi], stdout=devnull, stderr=devnull) == 234:
- _QCSAPI = qcsapi
- break
- except OSError:
- continue
+def _get_qcsapi():
+ """Detect Quantenna device."""
+ if not hasattr(_get_qcsapi, 'qcsapi'):
+ _get_qcsapi.qcsapi = None
+ if (utils.subprocess_quiet(['runnable', 'qcsapi_pcie_static']) == 0 and
+ utils.subprocess_quiet(['modinfo', 'qdpc-host'], no_stdout=True) == 0):
+ # qcsapi_pcie_static runs on PCIe hosts, e.g. GFRG250. qdpc-host is only
+ # loaded if a Quantenna device is present.
+ _get_qcsapi.qcsapi = 'qcsapi_pcie_static'
+ elif utils.subprocess_quiet(['runnable', 'call_qcsapi']) == 0:
+ # call_qcsapi runs on the LHOST, e.g. GFEX250.
+ _get_qcsapi.qcsapi = 'call_qcsapi'
+ return _get_qcsapi.qcsapi
def _qcsapi(*args):
- return subprocess.check_output([_QCSAPI] + list(args))
+ return subprocess.check_output([_get_qcsapi()] + list(args))
def _set(mode, opt):
@@ -85,7 +81,7 @@
def has_quantenna():
- return _QCSAPI is not None
+ return _get_qcsapi() is not None
def set_wifi(opt):
