Merge ~jocave/netplan/+git/netplan:dont-rebind-mwifiex into netplan:master

[Jonathan Cave]

We have found the mwifiex_pcie driver does not handle unbind/bind actions well. This manifested as frequent kernel panics when console-conf used netplan to configure interfaces on Ubuntu Core images.

[Martin Pitt (pitti)]

I'm fine with applying this patch, but note that mac80211_hwsim is a bit special: it genuinely doesn't even advertise rebinding, but it's also just being used for testing so it doesn't matter much.

OTOH mwifiex_pcie actually controls real hardware, and with that "netplan apply" would stop working for renames. Obviously you do call netplan apply (otherwise you wouldn't run into the crash), so I figure you do want it to actually apply.

Can you please file a bug against the kernel with the logs and traces so that this gets fixed properly eventually?

I also have an inline comment, see below.

5de3398... by Jonathan Cave on 2016-10-04

Keep individual driver checks and debug messages

[Martin Pitt (pitti)]

Thanks for the cleanup! I'll pull that into the package and xenial-updates backport. The latter will take a bit, so I take it in the meantime you want to land this in the snappy overlay PPA.

review: Approve

[Martin Pitt (pitti)]

Merged into trunk (squashed the three commits into one).

diff --git a/src/netplan b/src/netplan
index bdef802..e90720f 100755
--- a/src/netplan
+++ b/src/netplan
@@ -103,9 +103,14 @@ def replug(device):  # pragma: nocover (covered in autopkgtest)
     try:
         # we must resolve symlinks here as the device dir will be gone after unbind
         driver = os.path.realpath(os.path.join(devdir, 'device', 'driver'))
-        if os.path.basename(driver) == 'mac80211_hwsim':
+        driver_name = os.path.basename(driver)
+        if driver_name == 'mac80211_hwsim':
             logging.debug('replug %s: mac80211_hwsim does not support rebinding, ignoring', device)
             return False
+        # workaround for https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1630285
+        if driver_name == 'mwifiex_pcie':
+            logging.debug('replug %s: mwifiex_pcie crashes on rebinding, ignoring', device)
+            return False
         logging.debug('replug %s: unbinding %s from %s', device, devname, driver)
         with open(os.path.join(driver, 'unbind'), 'w') as f:
             f.write(devname)