On 24.11.19 15:19, André Przywara wrote:
On 24/11/2019 13:21, Jan Kiszka wrote:
Hi,
I'm trying to get CPU offlining work for Linux on the RPi4. In fact, this is working already with current ATF master and the Raspberry kernel 4.19.85. Not it would be "nice" if onlining worked as well:
Indeed.
[ 94.959294] CPU1: shutdown [ 94.959311] psci: CPU1 killed. [ 106.750960] CPU1: failed to come online [ 106.755425] CPU1: failed in unknown state : 0x0
Yeah, I remember there was an issue with that, but I didn't come around to fix that yet. I would have put this as a limitation in the cover letter, but: gerrit ...
Is this a known limitation? Or am I using the wrong kernel (obviously, it's a downstream one ;) )?
I obviously cannot endorse the usage of downstream kernels ;-), but I think I saw this with mainline as well.
Is mainline working on the RPi4 already? Well, another topic...
Do you get any more messages on the console? I think RPI3_RUNTIME_UART defaults to 0 for the RPI4 (more by accident), which should give you TF-A debug messages on PSCI calls. Maybe you can quickly add some, to see where it breaks?
I've instrumented the psci cpu off/on paths, and the enabling path after disabling never gets us into psci_warmboot_entrypoint() at least.
I might dig out my RPI4, but only later next week, so you might want to beat me on it, if you have your rig set up already.
I this working on the RPi3? I don't see much deviations between both in this regard.
Thanks, Jan
PS: Current RPi firmware requires an explicit "armstub=armstub8.bin" in config.txt, no automatic pickup.
Ah, thanks for the heads up. Feel free to send a documentation patch - if you are comfortable with gerrit, that is. Otherwise I would do it later on.
Well, gerrit... Let's see whether I'll be able to produce enough changes to be worth that trouble.
Thanks, Jan