Re: [PATCH 2/3] soc: qcom: qcom_stats: Add QMP support for syncing ddr stats

["Maulik Shah (mkshah)" <maulik.shah@oss.qualcomm.com>]

 

On 4/29/2025 4:09 PM, Konrad Dybcio wrote:
> On 4/29/25 5:52 AM, Maulik Shah wrote:
>> +	if (qcom_stats_qmp) {
>> +		/*
>> +		 * Recent SoCs (SM8450 onwards) do not have duration field
>> +		 * populated from boot up onwards for both DDR LPM Stats
>> +		 * and DDR Frequency Stats.
>> +		 *
>> +		 * Send QMP message to Always on processor which will
>> +		 * populate duration field into MSG RAM area.
>> +		 *
>> +		 * Sent everytime to read latest data.
>> +		 */
>> +		ret = qmp_send(qcom_stats_qmp, "{class: ddr, action: freqsync}");
>> +		if (ret)
>> +			seq_printf(s, "Error updating duration field %d\n", ret);
> 
> let's just return some error, instead of printing "error" successfully

Should i drop the print and also error, From details given in commit message of [1] 
which made the qcom_subsystem_sleep_stats_show() function return 0
in order to run command like below to collect the stats without interspersed errors
grep ^ /sys/kernel/debug/qcom_stats/*

The same may break if return error from ddr stats too.

[1] https://lore.kernel.org/r/20230119032329.2909383-1-swboyd@chromium.org 

> 
>> +	}
>> +
>>  	reg += DDR_STATS_ENTRY_START_ADDR;
>>  	memcpy_fromio(data, reg, sizeof(struct ddr_stats_entry) * entry_count);
>>  
>> @@ -310,6 +329,15 @@ static int qcom_stats_probe(struct platform_device *pdev)
>>  	qcom_create_subsystem_stat_files(root, config);
>>  	qcom_create_soc_sleep_stat_files(root, reg, d, config);
>>  	qcom_create_ddr_stat_files(root, reg, config);
>> +	/*
>> +	 * QMP is used for DDR stats syncing to MSG RAM for certain SoCs having
> 
> having what? (you could drop that word and the sentence would still make sense)

I will update the sentence  in v2.

Thanks,
Maulik
> 
>> +	 * (SM8450 onwards). The prior SoCs do not need QMP handle as the required
>> +	 * stats are already present in MSG RAM, provided the DDR_STATS_MAGIC_KEY
>> +	 * matches.
>> +	 */
> 
> Konrad