[PATCH 0/5] 0 MHz is not a valid current frequency

[Quan, Evan]

[AMD Official Use Only]

I agree with Lijo. 
Reporting a "round to the smallest operating frequency" just makes user more confusing. 
As per designed, the frequency marked with "*" should reflect the current clock frequency.

BR
Evan
> -----Original Message-----
> From: amd-gfx <amd-gfx-bounces at lists.freedesktop.org> On Behalf Of
> Lazar, Lijo
> Sent: Wednesday, October 13, 2021 12:14 PM
> To: Tuikov, Luben <Luben.Tuikov at amd.com>; amd-
> gfx at lists.freedesktop.org
> Cc: Deucher, Alexander <Alexander.Deucher at amd.com>
> Subject: Re: [PATCH 0/5] 0 MHz is not a valid current frequency
> 
> 
> 
> On 10/13/2021 8:40 AM, Luben Tuikov wrote:
> > Some ASIC support low-power functionality for the whole ASIC or just
> > an IP block. When in such low-power mode, some sysfs interfaces would
> > report a frequency of 0, e.g.,
> >
> > $cat /sys/class/drm/card0/device/pp_dpm_sclk
> > 0: 500Mhz
> > 1: 0Mhz *
> > 2: 2200Mhz
> > $_
> >
> > An operating frequency of 0 MHz doesn't make sense, and this interface
> > is designed to report only operating clock frequencies, i.e. non-zero,
> > and possibly the current one.
> >
> > When in this low-power state, round to the smallest operating
> > frequency, for this interface, as follows,
> >
> 
> Would rather avoid this -
> 
> 1) It is manipulating FW reported value. If at all there is an uncaught issue in
> FW reporting of frequency values, that is masked here.
> 2) Otherwise, if 0MHz is described as GFX power gated case, this provides a
> convenient interface to check if GFX is power gated.
> 
> If seeing a '0' is not pleasing, consider changing to something like
> 	"NA" - not available (frequency cannot be fetched at the moment).
> 
> Thanks,
> Lijo
> 
> > $cat /sys/class/drm/card0/device/pp_dpm_sclk
> > 0: 500Mhz *
> > 1: 2200Mhz
> > $_
> >
> > Luben Tuikov (5):
> >    drm/amd/pm: Slight function rename
> >    drm/amd/pm: Rename cur_value to curr_value
> >    drm/amd/pm: Rename freq_values --> freq_value
> >    dpm/amd/pm: Sienna: 0 MHz is not a current clock frequency
> >    dpm/amd/pm: Navi10: 0 MHz is not a current clock frequency
> >
> >   .../gpu/drm/amd/pm/swsmu/smu11/navi10_ppt.c   | 60 +++++++++------
> >   .../amd/pm/swsmu/smu11/sienna_cichlid_ppt.c   | 73 ++++++++++++-----
> --
> >   2 files changed, 86 insertions(+), 47 deletions(-)
> >