Thanks again Alex! Some comments inlined below: On 09/12/2021 15:06, Alex Deucher wrote: > Not really in a generic way. It's asic and platform specific. In > addition most modern displays require link training to bring up the > display, so you can't just save and restore registers. Oh sure, I understand that. My question is more like: is there a way, inside amdgpu driver, to save this state before taking over/overwriting/reprogramming the device? So we could (again, from inside the amdgpu driver) dump this pre-saved state in the shutdown handler, for example, having the device in a "pre-OS" state when the new kexec'ed kernel starts. > > The drivers are asic and platform specific. E.g., the driver for > vangogh is different from renoir is different from skylake, etc. The > display programming interfaces are asic specific. Cool, that makes sense! But if you (or anybody here) know some of these GOP drivers, e.g. for the qemu/qxl device, I'm just curious to see/understand how complex is the FW driver to just put the device/screen in a usable state. Cheers, Guilherme
