Re: [PATCH 2/3] firmware: arm_scmi: Add support for marking certain frequencies as boost

Sibi Sankar
2024-02-13T08:03:38Z

On 1/31/24 21:38, Sudeep Holla wrote:
> On Wed, Jan 31, 2024 at 03:29:43PM +0100, Pierre Gondois wrote:
>> Hello Sibi,
>>
>> On 1/17/24 12:04, Sibi Sankar wrote:
>>> All opps above the sustained level/frequency are treated as boost, so mark
>>> them accordingly.
>>>

Sudeep/Pierre,

Thanks for taking time to review the series.

>>> Suggested-by: Sudeep Holla <sudeep.holla@arm.com>
>>> Signed-off-by: Sibi Sankar <quic_sibis@quicinc.com>
>>> ---
>>> drivers/firmware/arm_scmi/perf.c | 11 ++++++++++-
>>> 1 file changed, 10 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/drivers/firmware/arm_scmi/perf.c b/drivers/firmware/arm_scmi/perf.c
>>> index e286f04ee6e3..d3fb8c804b3d 100644
>>> --- a/drivers/firmware/arm_scmi/perf.c
>>> +++ b/drivers/firmware/arm_scmi/perf.c
>>> @@ -811,7 +811,7 @@ static int scmi_dvfs_device_opps_add(const struct scmi_protocol_handle *ph,
>>> struct device *dev, u32 domain)
>>> {
>>> int idx, ret;
>>> - unsigned long freq;
>>> + unsigned long freq, sustained_freq;
>>> struct dev_pm_opp_data data = {};
>>> struct perf_dom_info *dom;
>>> @@ -819,12 +819,21 @@ static int scmi_dvfs_device_opps_add(const struct scmi_protocol_handle *ph,
>>> if (IS_ERR(dom))
>>> return PTR_ERR(dom);
>>> + if (!dom->level_indexing_mode)
>>> + sustained_freq = dom->sustained_perf_level * dom->mult_factor;
>>> + else
>>> + sustained_freq = dom->sustained_freq_khz * dom->mult_factor;
>>> +
>>> for (idx = 0; idx < dom->opp_count; idx++) {
>>> if (!dom->level_indexing_mode)
>>> freq = dom->opp[idx].perf * dom->mult_factor;
>>> else
>>> freq = dom->opp[idx].indicative_freq * dom->mult_factor;
>>> + /* All opps above the sustained level/frequency are treated as boost */
>>> + if (sustained_freq && freq > sustained_freq)
>>
>> It seems the sustained_freq is not optional since SCMI v1.0,
>> is it necessary to check that (sustained_freq != 0) ?
>>
>
> Technically correct, we don't have to. But since day 1, we checked and
> handled 0 for perf_level specifically to avoid division by zero. I am
> just worried if there are any platforms in the wild with these values as
> 0. We can start without the check and add it if someone complains perhaps ?

sure will drop the check in the re-spin.

-Sibi

>