On 8/15/24 08:56, Diederik de Haas wrote: > Hi, > > I recently bought an Asus ROG STRIX B550-F GAMING MB with an > AMD Ryzen 5 5500GT CPU (and installed the latest BIOS: 3607). > I'm running Debian Testing/Sid on it with kernel 6.9 and now 6.10 > and it seems to work great. > I've been doing some (unrelated) tests with `rngtest` from the > `rng-tools5` package and wondered how it would fare on my AMD CPU. I'm not very familiar with this test. What is the command line that you are using to invoke it? > > And I found out it doesn't work at all! > But on another system I have (Asus ROG CROSSHAIR VII HERO MB + > AMD Ryzen 1800X CPU) it works absolutely fine. > > # dmesg | grep ccp > [ 5.399853] ccp 0000:07:00.2: ccp: unable to access the device: you might > be running a broken BIOS. > [ 5.401031] ccp 0000:07:00.2: tee enabled > [ 5.401113] ccp 0000:07:00.2: psp enabled Which system is this output from? Can you provide the output from lspci -nn? Thanks, Tom > > Found an article [1] which could be relevant and downloaded and ran the > accompanying test program (written by Jason Donenfeld): > # ./amd-rdrand-bug > Your RDRAND() does not have the AMD bug. > # ./test-rdrand > RDRAND() =x47c993c0 > RDRAND() =xec7c697d > ... (more seemingly random numbers) > RDRAND() =xba858101 > > I tried it with the latest microcode dd 2024-07-10, but that didn't make > a difference. > > So I'd like to know if this may actually be a bug on the kernel side. > > Happy to provide additional information or run tests or try patches. > > Cheers, > Diederik > > [1] https://arstechnica.com/gadgets/2019/10/how-a-months-old-amd-microcode-bug-destroyed-my-weekend/
