On 02.06.22 14:56, Chen, Hongzhan wrote: > > >> -----Original Message----- >> From: Jan Kiszka <[email protected]> >> Sent: Thursday, June 2, 2022 5:54 PM >> To: Chen, Hongzhan <[email protected]>; [email protected] >> Subject: Re: [Cobalt Xenoami3.1 PATCH 0/2] notify Xenomai udpated clockfreq. >> >> On 27.05.22 08:22, Hongzhan Chen via Xenomai wrote: >>> When there is refined tsc clock, notify Xenomai to apply it. >>> Linux may schedule a delayed work to refine tsc clock and update >>> tsc_khz which happen after Xenomai finsih init but tsc_scale and >>> tsc_shift still keep the value depending on origianl tsc clock >>> which is outdated. The difference between two clocks may cause >>> timing issue. >>> >>> For example: >>> [ 0.001731] tsc: Detected 2899.886 MHz TSC >>> [ 5.588387] tsc: Refined TSC clocksource calibration: 2903.999 MHz >>> cat /sys/module/xenomai/parameters/clockfreq >>> 2899886000 >>> After patching, we like to use 2903.999 MHz. >>> >>> The patchset includes IPIPE patch and cobalt-patch. >>> >> >> Sounds reasonable, but you could help me with reviewing this by already >> answering: >> >> - How does dovetail (and xenomai 3.2 or evl) address this? > > So far , I have not found similar issue on dovetail-based. Dovetail-based > would go vdso uniformly so there is > no such issue but IPIPE would have to depend on tsc_khz value it got at > first to do translation even after tsc clockfreq is refined and changed.
Right, that is reason... > >> - Why is this tagged "3.1" only? >> - Which I-pipe series is this targeting (5.4, or also 4.19)? > > Currently , I just reproduced this issue and verified the patch on 5.4.133 + > xenomai 3.1. But according to [1] reported, > the issue can be found on 4.19 and I think my patch may work but I have not > verified on 4.19. > Please check stable/v3.2.x first (or as well) as that is the latest stable with I-pipe still included. Once the fix is merged there, we can pick it for 3.1 and possibly even 3.0 as well. Jan > Regards > > Hongzhan Chen > > > [1]: https://xenomai.org/pipermail/xenomai/2022-May/047770.html > -- Siemens AG, Technology Competence Center Embedded Linux
