答复: [外部邮件] Re: [PATCH v5 0/2] cpufreq: acpi-cpufreq: fix P-state index mismatch between perf->states[] and freq_table[]

["Li,Rongqing" <lirongqing@baidu.com>]

> > Patch 1/2 is unchanged from v4 and fixes the cached frequency used by
> > get_cur_freq_on_cpu() to detect a firmware frequency change behind the
> > OS's back.
> >
> > Patch 2/2 is new in v5.  As Rafael pointed out, Sashiko observed that
> > the extract_msr() fallback interferes with 1/2 and can render it
> > ineffective: when the status read from the hardware matches no
> > freq_table entry, extract_msr() returns freq_table[0].frequency
> > instead of reporting the status as unknown.  If the OS is already at
> > the P-state corresponding to freq_table[0], a firmware switch to a
> > filtered-out P-state then compares equal to the cached frequency,
> > data->resume is left clear and the next ->target() call does not
> > rewrite the control register.  So 1/2 alone does not make the
> > detection work in that case, and the two patches are posted together
> > rather than separately as I had suggested earlier.
> >
> > v4: https://lkml.iu.edu/2609.1/07369.html
> >
> > Changes since v4:
> >  - Drop "cpufreq: acpi-cpufreq: fix P-state index mismatch in
> >    extract_io()", which has been applied.  This series is based on top
> >    of it.
> >  - Add 2/2 to stop extract_msr() from masking firmware P-state changes,
> >    as reported by Sashiko, and note the dependency in 1/2's changelog.
> 
> So Sashiko has feedback on this one now:
> 
> https://sashiko.dev/#/message/20261106184008.1728-2-lirongqing%40baidu.
> com

This feedback is reasonable, I will send new version

thanks

[Li,Rongqing] 


> 
> >  - 1/2: no functional change; changelog extended to say that it fixes
> >    only the cached side of the comparison, and a duplicate
> >    Signed-off-by was removed.
> >
> > Li RongQing (2):
> >   cpufreq: acpi-cpufreq: fix P-state index mismatch in
> >     get_cur_freq_on_cpu()
> >   cpufreq: acpi-cpufreq: don't mask firmware P-state changes
> >
> >  drivers/cpufreq/acpi-cpufreq.c | 11 ++++++++---
> >  1 file changed, 8 insertions(+), 3 deletions(-)
> >
> > --
> > 2.9.4
> >