iv/linux
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

firmware: arm_scmi: Warn if domain frequency multiplier is 0 or rounded off

Browse Source 
When (sustained_freq_khz * 1000) is less than sustained_perf_level, the
multiplier will be less than 1 and hence rounded down as 0. Similarly if
it is not multiple of sustained_perf_level the dom_info->mult_factor will
contain rounded down value and will end up impacting all the frequency
calculations done using it.

Add warning if and when the domain frequency multiplier is 0 or rounded
down so that it gives a clue to get the firmware tables fixed.

Suggested-by: Pierre Gondois <Pierre.Gondois@arm.com>
Reviewed-by: Pierre Gondois <pierre.gondois@arm.com>
Reviewed-by: Cristian Marussi <cristian.marussi@arm.com>
Link: https://lore.kernel.org/r/20240119152338.3047620-1-sudeep.holla@arm.com
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
This commit is contained in:
Sudeep Holla 2024-01-19 15:23:37 +00:00
parent 6bd1b3fede
commit 534224b958
1 changed files with 17 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

19
drivers/firmware/arm_scmi/perf.c
View File

@ -270,15 +270,30 @@ scmi_perf_domain_attributes_get(const struct scmi_protocol_handle *ph,
le32_to_cpu(attr->sustained_freq_khz);
dom_info->sustained_perf_level =
le32_to_cpu(attr->sustained_perf_level);
/*
* sustained_freq_khz = mult_factor * sustained_perf_level
* mult_factor must be non zero positive integer(not fraction)
*/
if (!dom_info->sustained_freq_khz ||
!dom_info->sustained_perf_level ||
dom_info->level_indexing_mode)
dom_info->level_indexing_mode) {
/* CPUFreq converts to kHz, hence default 1000 */
dom_info->mult_factor = 1000;
else
} else {
dom_info->mult_factor =
(dom_info->sustained_freq_khz * 1000UL)
/ dom_info->sustained_perf_level;
if ((dom_info->sustained_freq_khz * 1000UL) %
dom_info->sustained_perf_level)
dev_warn(ph->dev,
"multiplier for domain %d rounded\n",
dom_info->id);
}
if (!dom_info->mult_factor)
dev_warn(ph->dev,
"Wrong sustained perf/frequency(domain %d)\n",
dom_info->id);
strscpy(dom_info->info.name, attr->name,
SCMI_SHORT_NAME_MAX_SIZE);
}