** Description changed: Impact: The wcn36xx driver in Xenial/linux-snapdragon had an ability to - autogerenate its MAC address upon boot, or read it from a file + autogenerate its MAC address upon boot, or read it from a file (/lib/firmware/wlan/macaddr0). The linux-snapdragon kernel in Bionic - doesn't have this ability. + doesn't have this feature. - While by itself it's not a bug (Xenial used a QCOM provided custom - driver, while Bionic uses the upstream wcn36xx driver) and can be - easility workarounded by specifying the hw address in - /etc/network/interfaces, or set via ifconfig on the commandline, it - turned out to be a real problem on ubuntu core: + While by itself not a bug (Xenial used a QCOM provided custom driver, + while Bionic uses the upstream wcn36xx driver), it can be easily work- + arounded by specifying the hw address in /etc/network/interfaces, or set + using ifconfig on the command line, but it turned out to be a real + problem on ubuntu core: - 1) upon boot, with now MAC address assigned, the wcn36xx assigns itself - the empty value "00:00:00:00:00" and that prevents the network interface - to work at all, until a valid address is set + 1) upon boot, with no MAC address assigned, the wcn36xx assigns itself the + dummy address "00:00:00:00:00" and that prevents the network interface from working at all, until a valid address is set - 2) the ubuntu core installed doesn't have any knowledge about this, it - tris to 'up' the interface and upon failure, it simply marks it as 'not - working' + 2) the ubuntu core installer doesn't have any knowledge about this + behaviour, it simply tries to bring up the interface and on failure, it + marks it as 'not working' - On top of that, ubuntu core ships a small script in initramfs that + On top of that, ubuntu core ships a small script in initramfs, that generates the /lib/firmware/wlan/macaddr0 file starting from the android boot serial, effectively generating a unique MAC address per board: - clearly, without driver support for this feature, the ubuntu core - efforts fall flat. + clearly, without driver support, this ubuntu core feature doesn't work. Fix: - Import back from Xenial the MAC generation mechanism: the pseudo random - generation and parsing of /lib/firmware/wlan/macaddr0 - see the attached - patch. + Import back the MAC generation mechanism from Xenial: the pseudo random + generation and the parsing of /lib/firmware/wlan/macaddr0 - see the attached patch. How to test: Unpon boot, if no /lib/firmware/wlan/macaddr0 is present, the kernel will print: - [ 10.612701] wcn36xx a204000.wcnss:smd-edge:wcnss:wifi: Direct firmware load for wlan/macaddr0 failed with error -2 - [ 10.612713] wcn36xx a204000.wcnss:smd-edge:wcnss:wifi: Failed (-2) to read macaddressfile wlan/macaddr0, using a random address instead + [ 10.612701] wcn36xx a204000.wcnss:smd-edge:wcnss:wifi: Direct firmware load for wlan/macaddr0 failed with error -2 + [ 10.612713] wcn36xx a204000.wcnss:smd-edge:wcnss:wifi: Failed (-2) to read macaddressfile wlan/macaddr0, using a random address instead ubuntu@dragon410c:~$ ifconfig wlan0 - wlan0: flags=4098<BROADCAST,MULTICAST> mtu 1500 - ether 00:0a:f5:d5:54:d7 txqueuelen 1000 (Ethernet) - RX packets 0 bytes 0 (0.0 B) - RX errors 0 dropped 0 overruns 0 frame 0 - TX packets 0 bytes 0 (0.0 B) - TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0 + wlan0: flags=4098<BROADCAST,MULTICAST> mtu 1500 + ether 00:0a:f5:d5:54:d7 txqueuelen 1000 (Ethernet) + RX packets 0 bytes 0 (0.0 B) + RX errors 0 dropped 0 overruns 0 frame 0 + TX packets 0 bytes 0 (0.0 B) + TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0 + else, if /lib/firmware/wlan/macaddr0 is present, its content will be + used to generate wlan0 MAC address: - else, if /lib/firmware/wlan/macaddr0 is present, its content will be used to generate wlan0 MAC address: - - ubuntu@dragon410c:~$ cat /lib/firmware/wlan/macaddr0 + ubuntu@dragon410c:~$ cat /lib/firmware/wlan/macaddr0 fe:1a:19:77:d9:88 ubuntu@dragon410c:~$ ifconfig wlan0 - wlan0: flags=4098<BROADCAST,MULTICAST> mtu 1500 - ether fe:1a:19:77:d9:88 txqueuelen 1000 (Ethernet) - RX packets 0 bytes 0 (0.0 B) - RX errors 0 dropped 0 overruns 0 frame 0 - TX packets 0 bytes 0 (0.0 B) - TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0 - + wlan0: flags=4098<BROADCAST,MULTICAST> mtu 1500 + ether fe:1a:19:77:d9:88 txqueuelen 1000 (Ethernet) + RX packets 0 bytes 0 (0.0 B) + RX errors 0 dropped 0 overruns 0 frame 0 + TX packets 0 bytes 0 (0.0 B) + TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0 Regression potential: Low - the patch is small and the code is wrapped in a Kconfig option - (WCN36XX_SNAPDRAGON_HACKS) that only affects the linux-snapdragon - flavour, leaving the generic kernel untouched. + (WCN36XX_SNAPDRAGON_HACKS) that only affects the linux-snapdragon flavour, + leaving the generic kernel untouched. ---
-- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1776491 Title: linux-snapdragon: wcn36xx: mac address generation on boot Status in linux package in Ubuntu: Incomplete Bug description: Impact: The wcn36xx driver in Xenial/linux-snapdragon had an ability to autogenerate its MAC address upon boot, or read it from a file (/lib/firmware/wlan/macaddr0). The linux-snapdragon kernel in Bionic doesn't have this feature. While by itself not a bug (Xenial used a QCOM provided custom driver, while Bionic uses the upstream wcn36xx driver), it can be easily work- arounded by specifying the hw address in /etc/network/interfaces, or set using ifconfig on the command line, but it turned out to be a real problem on ubuntu core: 1) upon boot, with no MAC address assigned, the wcn36xx assigns itself the dummy address "00:00:00:00:00" and that prevents the network interface from working at all, until a valid address is set 2) the ubuntu core installer doesn't have any knowledge about this behaviour, it simply tries to bring up the interface and on failure, it marks it as 'not working' On top of that, ubuntu core ships a small script in initramfs, that generates the /lib/firmware/wlan/macaddr0 file starting from the android boot serial, effectively generating a unique MAC address per board: clearly, without driver support, this ubuntu core feature doesn't work. Fix: Import back the MAC generation mechanism from Xenial: the pseudo random generation and the parsing of /lib/firmware/wlan/macaddr0 - see the attached patch. How to test: Unpon boot, if no /lib/firmware/wlan/macaddr0 is present, the kernel will print: [ 10.612701] wcn36xx a204000.wcnss:smd-edge:wcnss:wifi: Direct firmware load for wlan/macaddr0 failed with error -2 [ 10.612713] wcn36xx a204000.wcnss:smd-edge:wcnss:wifi: Failed (-2) to read macaddressfile wlan/macaddr0, using a random address instead ubuntu@dragon410c:~$ ifconfig wlan0 wlan0: flags=4098<BROADCAST,MULTICAST> mtu 1500 ether 00:0a:f5:d5:54:d7 txqueuelen 1000 (Ethernet) RX packets 0 bytes 0 (0.0 B) RX errors 0 dropped 0 overruns 0 frame 0 TX packets 0 bytes 0 (0.0 B) TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0 else, if /lib/firmware/wlan/macaddr0 is present, its content will be used to generate wlan0 MAC address: ubuntu@dragon410c:~$ cat /lib/firmware/wlan/macaddr0 fe:1a:19:77:d9:88 ubuntu@dragon410c:~$ ifconfig wlan0 wlan0: flags=4098<BROADCAST,MULTICAST> mtu 1500 ether fe:1a:19:77:d9:88 txqueuelen 1000 (Ethernet) RX packets 0 bytes 0 (0.0 B) RX errors 0 dropped 0 overruns 0 frame 0 TX packets 0 bytes 0 (0.0 B) TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0 Regression potential: Low - the patch is small and the code is wrapped in a Kconfig option (WCN36XX_SNAPDRAGON_HACKS) that only affects the linux-snapdragon flavour, leaving the generic kernel untouched. --- To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1776491/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : [email protected] Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp
