htc-msm-3.4
I emailed WisTilt2 this morning, and hopefully 3.4 will get added to the autobuild soon.
It's in pretty good shape now, but initially we had a few serious issues with this kernel.
- When it came out, there was a serious problem with the memory manager in the upstream 3.4 kernel that flat out broke the chroot system call (not just for us, but other users as well). If you have ever taken a peak at our initramfs, we use chroot (or rather switch_root) to maneuver onto our rootfs. We were stuck spinning our wheels until around 3.4.2 made an appearance on kernel.org and this problem was patched.
- We had another problem with the patches that instruct the vanilla linux kernel to use the android wake_locks infrastructure. Not sure who's to blame here, but I am inclined to think it's kernel.org again. At any rate, for the first time ever I saw frequent SODs on the 3.x kernels. I think we fixed this also.
- Finally, USB: I think we are victims of our own success here. To get adb, usb tethering etc, to work with android, we use android-specific patches on the vanilla linux kernel. As we progress to newer and newer kernels, so do these android patches. The problem is that ever since 3.0, google has stopped supporting gingerbread-like usb configurations in their kernel patches. So we've been dragging the usb layer from .39 all the way up to 3.3 -> this way we were successful in using the new kernels with gingerbread. This however is a HUGE hack and not good in any way shape or form. Finally something in the new 3.4 kernel prevents us to use the drivers from .39 and we were forced upgrade our usb layer, and together with it bring in ICS geared USB patches.
The result: with some work, we can get adb to work. However gingerbread is looking for active USB connections in the wrong place and even if you get ADB going, GB is unaware of an active usb connection so you can't enable other perks like USB tethering.
Not sure what the solution is to this last problem -> probably need to hack at frameworks in GBX but the motivation for this is somewhat low, since at that point we would need to be distributing a separate build to use specifically with 3.4.
Therefore finally, the current bug-list for 3.4:
1. Kexec is broken
2. USB: We can get ADB (instructions on this to follow), however USB notification doesn't work,
and consequently can't enable USB tethering. <---
see here how to take advantage of usb functionality on htc-msm-3.4
3. Bluetooth -> haven't looked at the BT patches yet, but hey BT never really works OK anyways.
On the bright side -> you will be using a kernel that's the bleeding edge in the linux world. Also, this might be placebo, but I think the new usb drivers manage the serial clocks better and perhaps power-management seems slightly better (interested in hearing how other folks think it compares).