- MP-safe drivers provide a mutex to ifmedia that is used to serialize
access to media-related structures / hardware regsiters. Converted
drivers use the new ifmedia_init_with_lock() function for this. The
new name is provided to ease the transition.
- Un-converted drivers continue to call ifmedia_init(), which will supply
a compatibility lock to be used instead. Several media-related entry
points must be aware of this compatibility lock, and are able to acquire
it recursively a limited number of times, if needed. This is a SPIN
mutex with priority IPL_NET.
- This same lock is used to serialize access to PHY registers and other
MII-related data structures.
The PHY drivers are modified to acquire and release the lock, as needed,
and assert the lock is held as a diagnostic aid.
The "usbnet" framework has had an overhaul of its internal locking
protocols to fit in with the media / mii changes, and the drivers adapted.
USB wifi drivers have been changed to provide their own adaptive mutex
to the ifmedia later via a new ieee80211_media_init_with_lock() function.
This is required because the USB drivers need an adaptive mutex.
Besised "usbnet", a few other drivers are converted: vmx, wm, ixgbe / ixv.
mcx also now calls ifmedia_init_with_lock() because it needs to also use
an adaptive mutex. The mcx driver still needs to be fully converted to
NET_MPSAFE.