Arch hangs on boot at vchiq_get_state

[LucidEye]

I am running Arch and I just did a system and firmware update "pacman -Syu" and "rpi-update" and soft-booted my pi. It booted just fine and everything looked ok on the boot messages... no errors.

Later I turned off the Pi and came back after dinner and powered it up and now it's hanging on the boot up process.

It gets about 36 lines into the boot messages and stops here every time:

] vc-cma: Videocore CMA driver
] vc-cma: vc_cma_base = 0xd400000
] vc-cma: vc_cma_size = 0x11800000 (280MiB)
] vc-cma: vc_cma_initial = 0x00000000 (0 MiB)
] brd: module loaded
] loop: moodule loaded
] vchiq: vchiq_init_state: slot_zero = 0xcd400000, is_master = 0
] vchiq_get_state: g_state.remote->initialized != 1 (0)

After reading a few things on this forum and others I did some experimenting and discovered that when I rem out the following lines in my config.txt file in the boot partition I can get the Pi to boot...

gpu_mem_512=316
gpu_mem_256=128
#cma_lwm=16
#cma_hwm=32
#cma_offline_start=16

I know these lines control the dynamic memory allocation between the CPU/GPU, but other than that I really have no idea what I am doing by reming out these 3 "cma" lines and what other things may stop functioning properly by doing this... all I know is this is the only way to get my Pi to boot right now.
Why are these settings apparently causing the Pi to crash on boot now after a software/firmware update when they worked OK before?
I know this is just a workaround to get it to boot, but I would like to know if anyone can tell me how to properly fix this problem as I would like to have the CMA working rather than just a hard split.
Thank you.

[dpm]

I have the same problem under Raspbian. I inserted cma entries today and hasn't booted since. I'll confirm reversing my changes fixes it later this week. Has an update been made that means dynamic memory allocation no longer works?

[edit]
Just realised I haven't helped myself by using old configuration as recommended here when really I should have used these. So this may well be a different issue.

[sdjf]

Later I turned off the Pi and came back after dinner and powered it up and now it's hanging on the boot up process.

If you turned off the Pi without a proper software shutdown, that could explain a lot of your problems, it can result in file system corruption. Never, ever turn off your Pi without first issuing a sync and then the poweroff commands.

[Aurelian_15]

I had the very same problem after a rpi-update with branch=next. Removing the cma lines from the config.txt solved the problem. The rpi has been rebooted with a soft "reboot".