[ccing Dominik (who authored the culprit) and Herbert (who merged it)] On 02.02.23 11:28, Linux kernel regression tracking (Thorsten Leemhuis) wrote: > > I noticed a regression report in bugzilla.kernel.org. As many (most?) > kernel developer don't keep an eye on it, I decided to forward it by > mail. Quoting from https://bugzilla.kernel.org/show_bug.cgi?id=216989 : Turns out according to a bisection from one of the reporters that b006c439d58d ("hwrng: core - start hwrng kthread also for untrusted sources") (merged for 6.1) apparently makes this hardware issue occur quicker/more frequently a lot quicker on any board that didn't get the firmware update yet. So it could be argued that from the point of the kernel it *might* be considered a regression. For details see the ticket. Ciao, Thorsten (wearing his 'the Linux kernel's regression tracker' hat) -- Everything you wanna know about Linux kernel regression tracking: https://linux-regtracking.leemhuis.info/about/#tldr If I did something stupid, please tell me, as explained on that page. #regzbot introduced: b006c439d58d >> reach622@xxxxxxxxxxx 2023-02-02 02:49:48 UTC >> >> Linux kernel >=6.1 exhibits a stuttering issue that occurs once every few hours. See https://www.reddit.com/r/archlinux/comments/zvgev0/audio_stuttering_issues_with_kernel_611/ https://www.reddit.com/r/linux_gaming/comments/zzqaf7/having_intermittent_stutters_with_a_ryzen_cpu/ https://bbs.archlinux.org/viewtopic.php?id=282333 for detailed information. >> >> The stutter lasts for 1-2 seconds and causes the framerate of the display to decrease dramatically and causes bursts in audio output. >> >> Additional info: >> >> * linux 6.1.0 or later >> >> Steps to reproduce: >> >> * Use Linux kernel >=6.1 >> >> * Use AMD Ryzen CPU with fTPM enabled >> >> * Wait for a few hours >> >> [reply] [−] Comment 1 Bell 2023-02-02 03:33:24 UTC >> >> Hey, Let me add some extra information to help. >> 1. this issue can happen in 6.2-rc6 without loading third-party kernel modules. (NVIDIA or Virtualbox and so) >> 2. some guy on the Desktop/Laptop who can disable ftpm and did eliminate the problem. >> 3. this problem can happen in newer AMD processors from the 4000 series to the 6000 series. >> 4. this problem isn't caused by the dedicated graphics card I guess, here are some combinations that stuttering can happen: >> AMD(built-in GPU) + NVIDIA Laptop >> AMD(No built-in GPU) + AMD(dedicated) Desktop >> AMD(built-in GPU) + AMD(dedicated) Laptop/Desktop >> AMD + AMD(Built-in GPU only) Laptop >> all suffer from this. >> >> Hope this can help :) > > See the ticket for more details. > > I briefly looked into the links and found this: > https://www.amd.com/en/support/kb/faq/pa-410 > >> >> Intermittent System Stutter Experienced with fTPM Enabled on Windows® 10 >> and 11 >> Article Number >> PA-410 >> >> This documentation provides information on improving intermittent >> performance stutter(s) on select PCs running Windows® 10 and 11 with >> Firmware Trusted Platform Module (“fTPM”) enabled. >> >> >> >> Issue Description >> >> AMD has determined that select AMD Ryzen™ system configurations may >> intermittently perform extended fTPM-related memory transactions in SPI >> flash memory (“SPIROM”) located on the motherboard, which can lead to >> temporary pauses in system interactivity or responsiveness until the >> transaction is concluded. >> >> >> >> Update and Workaround >> >> Update: Affected PCs will require a motherboard system BIOS (sBIOS) >> update containing enhanced modules for fTPM interaction with SPIROM. AMD >> expects that flashable customer sBIOS files to be available starting in >> early May, 2022. Exact BIOS availability timing for a specific >> motherboard depends on the testing and integration schedule of your >> manufacturer. Flashable updates for motherboards will be based on AMD >> AGESA 1207 (or newer). >> >> Workaround: As an immediate solution, affected customers dependent >> on fTPM functionality for Trusted Platform Module support may instead >> use a hardware TPM (“dTPM”) device for trusted computing. Platform dTPM >> modules utilize onboard non-volatile memory (NVRAM) that supersedes the >> TPM/SPIROM interaction described in this article. >> >> COMPATIBILITY: Please check with your system or motherboard >> manufacturer to ensure that your platform supports add-in dTPM modules >> before attempting or implementing this workaround. >> >> WARNING: If switching an active system from fTPM to dTPM, it is >> critical that you disable TPM-backed encryption systems (e.g. BitLocker >> Drive Encryption) and/or back up vital system data prior to switching >> TPM devices. You must have full administrative access to the system, or >> explicit support from your IT administrator if the system is managed. >> For more information on transferring ownership to a new TPM device, >> please visit this Microsoft webpage. >> > > So it's a firmware problem, but apparently one that Linux only triggers > since 6.1. > > Jason, could the hwrng changes have anything to do with this? > > A bisection really would be helpful, but I guess that is not easy as the > problem apparently only shows up after some time... > > > Anyway: > > [TLDR for the rest of this mail: I'm adding this report to the list of > tracked Linux kernel regressions; the text you find below is based on a > few templates paragraphs you might have encountered already in similar > form.] > > BTW, let me use this mail to also add the report to the list of tracked > regressions to ensure it's doesn't fall through the cracks: > > #regzbot introduced: v6.0..v6.1 > https://bugzilla.kernel.org/show_bug.cgi?id=216989 > #regzbot title: tpm: systems with AMD Ryzen stutter when fTPM is enabled > #regzbot ignore-activity > > This isn't a regression? This issue or a fix for it are already > discussed somewhere else? It was fixed already? You want to clarify when > the regression started to happen? Or point out I got the title or > something else totally wrong? Then just reply and tell me -- ideally > while also telling regzbot about it, as explained by the page listed in > the footer of this mail. > > Developers: When fixing the issue, remember to add 'Link:' tags pointing > to the report (e.g. the buzgzilla ticket and maybe this mail as well, if > this thread sees some discussion). See page linked in footer for details. > > Ciao, Thorsten (wearing his 'the Linux kernel's regression tracker' hat) > -- > Everything you wanna know about Linux kernel regression tracking: > https://linux-regtracking.leemhuis.info/about/#tldr > If I did something stupid, please tell me, as explained on that page.
