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

[Lazar, Lijo]

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(-)
>