Commit 7c0dde86 authored by Zihuan Zhang's avatar Zihuan Zhang Committed by Rafael J. Wysocki
Browse files

cpufreq: Add defensive check during driver registration 



Currently, cpufreq allows drivers to implement both ->target() and
->target_index() callbacks, but that can lead to ambiguous or incorrect
behavior.

For this reason, prevent cpufreq drivers implementing both ->target()
and ->target_index() at the same time from registering.

This check can help to catch driver implementation mistakes early and
improve overall robustness, without affecting existing valid drivers.

Signed-off-by: default avatarZihuan Zhang <zhangzihuan@kylinos.cn>
Link: https://patch.msgid.link/20250908085738.31602-1-zhangzihuan@kylinos.cn


[ rjw: Subject adjustment and changelog rewrite ]
Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
parent 46c435cb

drivers/cpufreq/cpufreq.c

+1 −0
Original line number Diff line number Diff line
@@ -2911,6 +2911,7 @@ int cpufreq_register_driver(struct cpufreq_driver *driver_data) 
		return -EPROBE_DEFER;



	if (!driver_data || !driver_data->verify || !driver_data->init ||

	     (driver_data->target_index && driver_data->target) ||

	     (!!driver_data->setpolicy == (driver_data->target_index || driver_data->target)) ||

	     (!driver_data->get_intermediate != !driver_data->target_intermediate) ||

	     (!driver_data->online != !driver_data->offline) ||