Re: [PATCH v3 1/3] cpufreq: mediatek: using global lock avoid race condition
From: Chun-Jen Tseng (曾俊仁)
Date: Thu Mar 20 2025 - 04:26:57 EST
Hi Dan,
Thanks your remind. I will be careful and fix it before submit new
patch.
BRs,
Mark Tseng
On Wed, 2025-02-19 at 10:23 +0300, Dan Carpenter wrote:
>
> External email : Please do not click links or open attachments until
> you have verified the sender or the content.
>
>
> Hi Mark,
>
> kernel test robot noticed the following build warnings:
>
> https://urldefense.com/v3/__https://git-scm.com/docs/git-format-patch*_base_tree_information__;Iw!!CTRNKA9wMg0ARbw!ixPI3aPvvJSSIiRSm4TttWZyeSNnZsdzX-4zYkY7Ax1faRLZBJ7JW3Fmf7O8BYXiyHlxDC6aauOslVt8KEW_jViJAkm7uw$
> ]
>
> url:
> https://urldefense.com/v3/__https://github.com/intel-lab-lkp/linux/commits/Mark-Tseng/cpufreq-mediatek-using-global-lock-avoid-race-condition/20250214-154521__;!!CTRNKA9wMg0ARbw!ixPI3aPvvJSSIiRSm4TttWZyeSNnZsdzX-4zYkY7Ax1faRLZBJ7JW3Fmf7O8BYXiyHlxDC6aauOslVt8KEW_jVj9Egobdw$
> base:
> https://urldefense.com/v3/__https://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm.git__;!!CTRNKA9wMg0ARbw!ixPI3aPvvJSSIiRSm4TttWZyeSNnZsdzX-4zYkY7Ax1faRLZBJ7JW3Fmf7O8BYXiyHlxDC6aauOslVt8KEW_jVg7ujqlQw$
> linux-next
> patch link:
> https://lore.kernel.org/r/20250214074353.1169864-2-chun-jen.tseng%40mediatek.com
> patch subject: [PATCH v3 1/3] cpufreq: mediatek: using global lock
> avoid race condition
> config: sparc-randconfig-r071-20250218
> (https://urldefense.com/v3/__https://download.01.org/0day-ci/archive/
> 20250219/202502190807.fz6fs2jz-lkp@xxxxxxxxx/config__;!!CTRNKA9wMg0AR
> bw!ixPI3aPvvJSSIiRSm4TttWZyeSNnZsdzX-
> 4zYkY7Ax1faRLZBJ7JW3Fmf7O8BYXiyHlxDC6aauOslVt8KEW_jVhUidk_DA$ )
> compiler: sparc64-linux-gcc (GCC) 14.2.0
>
> If you fix the issue in a separate patch/commit (i.e. not just a new
> version of
> the same patch/commit), kindly add following tags
> > Reported-by: kernel test robot <lkp@xxxxxxxxx>
> > Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
> > Closes:
> > https://lore.kernel.org/r/202502190807.fz6fs2jz-lkp@xxxxxxxxx/
>
> smatch warnings:
> drivers/cpufreq/mediatek-cpufreq.c:367 mtk_cpufreq_opp_notifier()
> warn: inconsistent returns 'global &mtk_policy_lock'.
>
> vim +367 drivers/cpufreq/mediatek-cpufreq.c
>
> c210063b40acab drivers/cpufreq/mediatek-cpufreq.c Rex-BC Chen 2022-
> 05-05 317 static int mtk_cpufreq_opp_notifier(struct notifier_block
> *nb,
> c210063b40acab drivers/cpufreq/mediatek-cpufreq.c Rex-BC Chen 2022-
> 05-05 318 unsigned long event,
> void *data)
> c210063b40acab drivers/cpufreq/mediatek-cpufreq.c Rex-BC Chen 2022-
> 05-05 319 {
> 5f81d7eeae239d drivers/cpufreq/mediatek-cpufreq.c Mark Tseng 2025-
> 02-14 320 struct dev_pm_opp *opp;
> c210063b40acab drivers/cpufreq/mediatek-cpufreq.c Rex-BC Chen 2022-
> 05-05 321 struct dev_pm_opp *new_opp;
> c210063b40acab drivers/cpufreq/mediatek-cpufreq.c Rex-BC Chen 2022-
> 05-05 322 struct mtk_cpu_dvfs_info *info;
> c210063b40acab drivers/cpufreq/mediatek-cpufreq.c Rex-BC Chen 2022-
> 05-05 323 unsigned long freq, volt;
> c210063b40acab drivers/cpufreq/mediatek-cpufreq.c Rex-BC Chen 2022-
> 05-05 324 struct cpufreq_policy *policy;
> c210063b40acab drivers/cpufreq/mediatek-cpufreq.c Rex-BC Chen 2022-
> 05-05 325 int ret = 0;
> c210063b40acab drivers/cpufreq/mediatek-cpufreq.c Rex-BC Chen 2022-
> 05-05 326
> 5f81d7eeae239d drivers/cpufreq/mediatek-cpufreq.c Mark Tseng 2025-
> 02-14 327 mutex_lock(&mtk_policy_lock);
> 5f81d7eeae239d drivers/cpufreq/mediatek-cpufreq.c Mark Tseng 2025-
> 02-14 328 opp = data;
> c210063b40acab drivers/cpufreq/mediatek-cpufreq.c Rex-BC Chen 2022-
> 05-05 329 info = container_of(nb, struct mtk_cpu_dvfs_info,
> opp_nb);
> c210063b40acab drivers/cpufreq/mediatek-cpufreq.c Rex-BC Chen 2022-
> 05-05 330
> c210063b40acab drivers/cpufreq/mediatek-cpufreq.c Rex-BC Chen 2022-
> 05-05 331 if (event == OPP_EVENT_ADJUST_VOLTAGE) {
> c210063b40acab drivers/cpufreq/mediatek-cpufreq.c Rex-BC Chen 2022-
> 05-05 332 freq = dev_pm_opp_get_freq(opp);
> c210063b40acab drivers/cpufreq/mediatek-cpufreq.c Rex-BC Chen 2022-
> 05-05 333
> c210063b40acab drivers/cpufreq/mediatek-cpufreq.c Rex-BC Chen 2022-
> 05-05 334 if (info->current_freq == freq) {
> c210063b40acab drivers/cpufreq/mediatek-cpufreq.c Rex-BC Chen 2022-
> 05-05 335 volt =
> dev_pm_opp_get_voltage(opp);
> c210063b40acab drivers/cpufreq/mediatek-cpufreq.c Rex-BC Chen 2022-
> 05-05 336 ret =
> mtk_cpufreq_set_voltage(info, volt);
> c210063b40acab drivers/cpufreq/mediatek-cpufreq.c Rex-BC Chen 2022-
> 05-05 337 if (ret)
> c210063b40acab drivers/cpufreq/mediatek-cpufreq.c Rex-BC Chen 2022-
> 05-05 338 dev_err(info->cpu_dev,
> c210063b40acab drivers/cpufreq/mediatek-cpufreq.c Rex-BC Chen 2022-
> 05-05 339 "failed to scale
> voltage: %d\n", ret);
> c210063b40acab drivers/cpufreq/mediatek-cpufreq.c Rex-BC Chen 2022-
> 05-05 340 }
> c210063b40acab drivers/cpufreq/mediatek-cpufreq.c Rex-BC Chen 2022-
> 05-05 341 } else if (event == OPP_EVENT_DISABLE) {
> c210063b40acab drivers/cpufreq/mediatek-cpufreq.c Rex-BC Chen 2022-
> 05-05 342 freq = dev_pm_opp_get_freq(opp);
> c210063b40acab drivers/cpufreq/mediatek-cpufreq.c Rex-BC Chen 2022-
> 05-05 343
> c210063b40acab drivers/cpufreq/mediatek-cpufreq.c Rex-BC Chen 2022-
> 05-05 344 /* case of current opp item is disabled */
> c210063b40acab drivers/cpufreq/mediatek-cpufreq.c Rex-BC Chen 2022-
> 05-05 345 if (info->current_freq == freq) {
> c210063b40acab drivers/cpufreq/mediatek-cpufreq.c Rex-BC Chen 2022-
> 05-05 346 freq = 1;
> c210063b40acab drivers/cpufreq/mediatek-cpufreq.c Rex-BC Chen 2022-
> 05-05 347 new_opp =
> dev_pm_opp_find_freq_ceil(info->cpu_dev,
> c210063b40acab drivers/cpufreq/mediatek-cpufreq.c Rex-BC Chen 2022-
> 05-05
> 348
> &freq);
> c210063b40acab drivers/cpufreq/mediatek-cpufreq.c Rex-BC Chen 2022-
> 05-05 349 if (IS_ERR(new_opp)) {
> c210063b40acab drivers/cpufreq/mediatek-cpufreq.c Rex-BC Chen 2022-
> 05-05 350 dev_err(info->cpu_dev,
> c210063b40acab drivers/cpufreq/mediatek-cpufreq.c Rex-BC Chen 2022-
> 05-05 351 "all opp items are
> disabled\n");
> c210063b40acab drivers/cpufreq/mediatek-cpufreq.c Rex-BC Chen 2022-
> 05-05 352 ret = PTR_ERR(new_opp);
> c210063b40acab drivers/cpufreq/mediatek-cpufreq.c Rex-BC Chen 2022-
> 05-05 353 return
> notifier_from_errno(ret);
>
> mutex_unlock(&mtk_policy_lock) before returning.
>
> c210063b40acab drivers/cpufreq/mediatek-cpufreq.c Rex-BC Chen 2022-
> 05-05 354 }
> c210063b40acab drivers/cpufreq/mediatek-cpufreq.c Rex-BC Chen 2022-
> 05-05 355
> c210063b40acab drivers/cpufreq/mediatek-cpufreq.c Rex-BC Chen 2022-
> 05-05 356 dev_pm_opp_put(new_opp);
> c210063b40acab drivers/cpufreq/mediatek-cpufreq.c Rex-BC Chen 2022-
> 05-05 357 policy = cpufreq_cpu_get(info-
> >opp_cpu);
> c210063b40acab drivers/cpufreq/mediatek-cpufreq.c Rex-BC Chen 2022-
> 05-05 358 if (policy) {
> c210063b40acab drivers/cpufreq/mediatek-cpufreq.c Rex-BC Chen 2022-
> 05-05 359
> cpufreq_driver_target(policy, freq / 1000,
> c210063b40acab drivers/cpufreq/mediatek-cpufreq.c Rex-BC Chen 2022-
> 05-05 360
> CPUFREQ_RELATION_L);
> c210063b40acab drivers/cpufreq/mediatek-cpufreq.c Rex-BC Chen 2022-
> 05-05 361 cpufreq_cpu_put(policy);
> c210063b40acab drivers/cpufreq/mediatek-cpufreq.c Rex-BC Chen 2022-
> 05-05 362 }
> c210063b40acab drivers/cpufreq/mediatek-cpufreq.c Rex-BC Chen 2022-
> 05-05 363 }
> c210063b40acab drivers/cpufreq/mediatek-cpufreq.c Rex-BC Chen 2022-
> 05-05 364 }
> 5f81d7eeae239d drivers/cpufreq/mediatek-cpufreq.c Mark Tseng 2025-
> 02-14 365 mutex_unlock(&mtk_policy_lock);
> c210063b40acab drivers/cpufreq/mediatek-cpufreq.c Rex-BC Chen 2022-
> 05-05 366
> c210063b40acab drivers/cpufreq/mediatek-cpufreq.c Rex-BC Chen 2022-
> 05-05 @367 return notifier_from_errno(ret);
> c210063b40acab drivers/cpufreq/mediatek-cpufreq.c Rex-BC Chen 2022-
> 05-05 368 }
>
> --
> 0-DAY CI Kernel Test Service
> https://urldefense.com/v3/__https://github.com/intel/lkp-tests/wiki__;!!CTRNKA9wMg0ARbw!ixPI3aPvvJSSIiRSm4TttWZyeSNnZsdzX-4zYkY7Ax1faRLZBJ7JW3Fmf7O8BYXiyHlxDC6aauOslVt8KEW_jVii1cx6tQ$
>