wget https://docs.broadcom.com/docs-and-downloads/raid-controllers/raid-controllers-common-files/8-07-14_MegaCLI.zip
unzip 8-07-14_MegaCLI.zip
cd Linux
sudo alien MegaCli-8.07.14-1.noarch.rpm
sudo dpkg -imegacli_8.07.14-2_all.deb
/opt/MegaRAID/MegaCli/MegaCli64 -h
All I can tell you is it works for me. Here's my various config options and some sample MegaCli output.
When I first got this server I spent a good while making sure all it's various firmwares were as recent as possible, including the RAID cards.
I've two controllers installed currently and they both work fine.
Note that the 'Error Code' for some MegaCli commands returns the parameter queried as opposed to an actuall error code. (eg AdpCount)
I do have modules loaded to allow passthrough of the cards into a VM, but I'm NOT actually doing that at the moment so Proxmox can use them. Not sure if that would make a difference though.
Loaded in /etc/modules
Additional GRUB kernel parameter in /etc/default/grub
My OS, Firmware & Driver versions...
A few sample MegaCli commands:
I hope there's something here that might give you an idea.
Good luck!