AMD WBRF Ready For Linux 6.8 To Mitigate WiFi Radio Interference

[phoronix]

Phoronix: AMD WBRF Ready For Linux 6.8 To Mitigate WiFi Radio Interference

Since earlier this year AMD has been working on Linux support for WBRF for mitigating WiFi radio frequency interference (RFI) with their latest Ryzen 7000 and forthcoming Ryzen 8000 series mobile processors. That work looks like it will be ready to land in Linux 6.8...

https://www.phoronix.com/news/AMD-WBRF-For-Linux-6.8

[Spring]

What's being protected from what? Are Wi-Fi chips the vulnerable IC here? It's not like DDR emits a lot of radio, does it? DDR5 traces are even shielded by ground planes from both sides on all motherboards I've seen in Internet.

[skeevy420]

What's being protected from what? Are Wi-Fi chips the vulnerable IC here? It's not like DDR emits a lot of radio, does it? DDR5 traces are even shielded by ground planes from both sides on all motherboards I've seen in Internet.

WiFi and DDR5 can run at the same frequencies and if their frequencies happen to line up it can cause harmonic resonance issues. It's not DDR5 emitting radio, it's WiFi broadcasting at the same frequency as the DDR5 which causes the DRR5 to go funky.

Music concerts do the same thing with speaker placement. Aim the speakers in the right directions so they'll align over the audience and they'll sound twice as loud. In this case, the WiFi and DDR5 signals meet up in the ram chips and, instead of getting double the frequency from the harmonic resonance like concerts get double the volume, your shit crashes.

[Lord Byron II]

It seems like this would just be a BIOS update to keep the RAM out of the sensitive ranges. But kernel changes imply that this is being managed at runtime, like the RAM speed may be changed, but only if a certain radio is in use. Does this mean that your computer might slow down (slightly) if you connect to certain networks?

[ssokolow]

WiFi and DDR5 can run at the same frequencies and if their frequencies happen to line up it can cause harmonic resonance issues. It's not DDR5 emitting radio, it's WiFi broadcasting at the same frequency as the DDR5 which causes the DRR5 to go funky.

Music concerts do the same thing with speaker placement. Aim the speakers in the right directions so they'll align over the audience and they'll sound twice as loud. In this case, the WiFi and DDR5 signals meet up in the ram chips and, instead of getting double the frequency from the harmonic resonance like concerts get double the volume, your shit crashes.

Really? I thought it was about preventing the DDR5 clock from accidentally acting as a localized WiFi jammer and crapping out your WiFi signal strength. That'd make more sense, given how much the set of usable WiFi frequencies is determined by local regulations and how, to minimize congestion, you'll want to be able to choose between every frequency band local law allows. That sort of "which regulations are we complying with?" stuff is the sort of thing you can't just do once for all locales in the BIOS/UEFI.