kernel/power/energy_model.c:649 em_dev_register_pd_no_update() error: we previously assumed 'dev->em_pd' could be null (see line 594)
kernel test robot <[email protected]> Thu, 30 Jul 2026 16:15:13 +0800
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BCC: [email protected] CC: [email protected] CC: [email protected] TO: "Rafael J. Wysocki" <[email protected]> tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master head: 11028ab62899e4191e074ee364c712b77823a9c4 commit: e0423541477dfb684fbc6e6b5386054bc650f264 PM: EM: Add function for registering a PD without capacity update date: 11 months ago :::::: branch date: 8 hours ago :::::: commit date: 11 months ago config: i386-randconfig-141-20260730 (https://download.01.org/0day-ci/archive/20260730/[email protected]/config) compiler: gcc-14 (Debian 14.2.0-19) 14.2.0 smatch: v0.5.0-9187-g5189e3fb 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 | Fixes: e0423541477d ("PM: EM: Add function for registering a PD without capacity update") | Reported-by: kernel test robot <[email protected]> | Reported-by: Dan Carpenter <[email protected]> | Closes: https://lore.kernel.org/r/[email protected]/ smatch warnings: kernel/power/energy_model.c:649 em_dev_register_pd_no_update() error: we previously assumed 'dev->em_pd' could be null (see line 594) vim +649 kernel/power/energy_model.c e0423541477dfb6 Rafael J. Wysocki 2025-09-05 564 e0423541477dfb6 Rafael J. Wysocki 2025-09-05 565 /** e0423541477dfb6 Rafael J. Wysocki 2025-09-05 566 * em_dev_register_pd_no_update() - Register a perf domain for a device e0423541477dfb6 Rafael J. Wysocki 2025-09-05 567 * @dev : Device to register the PD for e0423541477dfb6 Rafael J. Wysocki 2025-09-05 568 * @nr_states : Number of performance states in the new PD e0423541477dfb6 Rafael J. Wysocki 2025-09-05 569 * @cb : Callback functions for populating the energy model e0423541477dfb6 Rafael J. Wysocki 2025-09-05 570 * @cpus : CPUs to include in the new PD (mandatory if @dev is a CPU device) e0423541477dfb6 Rafael J. Wysocki 2025-09-05 571 * @microwatts : Whether or not the power values in the EM will be in uW e0423541477dfb6 Rafael J. Wysocki 2025-09-05 572 * e0423541477dfb6 Rafael J. Wysocki 2025-09-05 573 * Like em_dev_register_perf_domain(), but does not trigger a CPU capacity e0423541477dfb6 Rafael J. Wysocki 2025-09-05 574 * update after registering the PD, even if @dev is a CPU device. e0423541477dfb6 Rafael J. Wysocki 2025-09-05 575 */ e0423541477dfb6 Rafael J. Wysocki 2025-09-05 576 int em_dev_register_pd_no_update(struct device *dev, unsigned int nr_states, e0423541477dfb6 Rafael J. Wysocki 2025-09-05 577 const struct em_data_callback *cb, e0423541477dfb6 Rafael J. Wysocki 2025-09-05 578 const cpumask_t *cpus, bool microwatts) 27871f7a8a341ef Quentin Perret 2018-12-03 579 { 3ee7be9e10dd5f7 Rafael J. Wysocki 2025-03-06 580 struct em_perf_table *em_table; 27871f7a8a341ef Quentin Perret 2018-12-03 581 unsigned long cap, prev_cap = 0; 91362463114eb63 Lukasz Luba 2022-03-21 582 unsigned long flags = 0; 1bc138c62295997 Lukasz Luba 2020-06-10 583 int cpu, ret; 27871f7a8a341ef Quentin Perret 2018-12-03 584 1bc138c62295997 Lukasz Luba 2020-06-10 585 if (!dev || !nr_states || !cb) 27871f7a8a341ef Quentin Perret 2018-12-03 586 return -EINVAL; 27871f7a8a341ef Quentin Perret 2018-12-03 587 27871f7a8a341ef Quentin Perret 2018-12-03 588 /* 27871f7a8a341ef Quentin Perret 2018-12-03 589 * Use a mutex to serialize the registration of performance domains and 27871f7a8a341ef Quentin Perret 2018-12-03 590 * let the driver-defined callback functions sleep. 27871f7a8a341ef Quentin Perret 2018-12-03 591 */ 27871f7a8a341ef Quentin Perret 2018-12-03 592 mutex_lock(&em_pd_mutex); 27871f7a8a341ef Quentin Perret 2018-12-03 593 1bc138c62295997 Lukasz Luba 2020-06-10 @594 if (dev->em_pd) { 27871f7a8a341ef Quentin Perret 2018-12-03 595 ret = -EEXIST; 27871f7a8a341ef Quentin Perret 2018-12-03 596 goto unlock; 27871f7a8a341ef Quentin Perret 2018-12-03 597 } 27871f7a8a341ef Quentin Perret 2018-12-03 598 1bc138c62295997 Lukasz Luba 2020-06-10 599 if (_is_cpu_device(dev)) { 1bc138c62295997 Lukasz Luba 2020-06-10 600 if (!cpus) { 1bc138c62295997 Lukasz Luba 2020-06-10 601 dev_err(dev, "EM: invalid CPU mask\n"); 1bc138c62295997 Lukasz Luba 2020-06-10 602 ret = -EINVAL; 1bc138c62295997 Lukasz Luba 2020-06-10 603 goto unlock; 1bc138c62295997 Lukasz Luba 2020-06-10 604 } 1bc138c62295997 Lukasz Luba 2020-06-10 605 1bc138c62295997 Lukasz Luba 2020-06-10 606 for_each_cpu(cpu, cpus) { 1bc138c62295997 Lukasz Luba 2020-06-10 607 if (em_cpu_get(cpu)) { 1bc138c62295997 Lukasz Luba 2020-06-10 608 dev_err(dev, "EM: exists for CPU%d\n", cpu); 1bc138c62295997 Lukasz Luba 2020-06-10 609 ret = -EEXIST; 1bc138c62295997 Lukasz Luba 2020-06-10 610 goto unlock; 1bc138c62295997 Lukasz Luba 2020-06-10 611 } 27871f7a8a341ef Quentin Perret 2018-12-03 612 /* 1bc138c62295997 Lukasz Luba 2020-06-10 613 * All CPUs of a domain must have the same 1bc138c62295997 Lukasz Luba 2020-06-10 614 * micro-architecture since they all share the same 1bc138c62295997 Lukasz Luba 2020-06-10 615 * table. 27871f7a8a341ef Quentin Perret 2018-12-03 616 */ 8ec59c0f5f4966f Vincent Guittot 2019-06-17 617 cap = arch_scale_cpu_capacity(cpu); 27871f7a8a341ef Quentin Perret 2018-12-03 618 if (prev_cap && prev_cap != cap) { 1bc138c62295997 Lukasz Luba 2020-06-10 619 dev_err(dev, "EM: CPUs of %*pbl must have the same capacity\n", 1bc138c62295997 Lukasz Luba 2020-06-10 620 cpumask_pr_args(cpus)); 1bc138c62295997 Lukasz Luba 2020-06-10 621 27871f7a8a341ef Quentin Perret 2018-12-03 622 ret = -EINVAL; 27871f7a8a341ef Quentin Perret 2018-12-03 623 goto unlock; 27871f7a8a341ef Quentin Perret 2018-12-03 624 } 27871f7a8a341ef Quentin Perret 2018-12-03 625 prev_cap = cap; 27871f7a8a341ef Quentin Perret 2018-12-03 626 } 1bc138c62295997 Lukasz Luba 2020-06-10 627 } 27871f7a8a341ef Quentin Perret 2018-12-03 628 ae6ccaa650380d2 Lukasz Luba 2022-07-07 629 if (microwatts) ae6ccaa650380d2 Lukasz Luba 2022-07-07 630 flags |= EM_PERF_DOMAIN_MICROWATTS; 91362463114eb63 Lukasz Luba 2022-03-21 631 else if (cb->get_cost) 91362463114eb63 Lukasz Luba 2022-03-21 632 flags |= EM_PERF_DOMAIN_ARTIFICIAL; 91362463114eb63 Lukasz Luba 2022-03-21 633 3acec69a94eaaf3 Lukasz Luba 2024-03-08 634 /* 3acec69a94eaaf3 Lukasz Luba 2024-03-08 635 * EM only supports uW (exception is artificial EM). 3acec69a94eaaf3 Lukasz Luba 2024-03-08 636 * Therefore, check and force the drivers to provide 3acec69a94eaaf3 Lukasz Luba 2024-03-08 637 * power in uW. 3acec69a94eaaf3 Lukasz Luba 2024-03-08 638 */ 3acec69a94eaaf3 Lukasz Luba 2024-03-08 639 if (!microwatts && !(flags & EM_PERF_DOMAIN_ARTIFICIAL)) { 3acec69a94eaaf3 Lukasz Luba 2024-03-08 640 dev_err(dev, "EM: only supports uW power values\n"); 3acec69a94eaaf3 Lukasz Luba 2024-03-08 641 ret = -EINVAL; 3acec69a94eaaf3 Lukasz Luba 2024-03-08 642 goto unlock; 3acec69a94eaaf3 Lukasz Luba 2024-03-08 643 } 3acec69a94eaaf3 Lukasz Luba 2024-03-08 644 91362463114eb63 Lukasz Luba 2022-03-21 645 ret = em_create_pd(dev, nr_states, cb, cpus, flags); 1bc138c62295997 Lukasz Luba 2020-06-10 646 if (ret) 27871f7a8a341ef Quentin Perret 2018-12-03 647 goto unlock; 27871f7a8a341ef Quentin Perret 2018-12-03 648 91362463114eb63 Lukasz Luba 2022-03-21 @649 dev->em_pd->flags |= flags; 5609296750afd64 Lukasz Luba 2024-10-30 650 dev->em_pd->min_perf_state = 0; 5609296750afd64 Lukasz Luba 2024-10-30 651 dev->em_pd->max_perf_state = nr_states - 1; c250d50fe2ce627 Lukasz Luba 2020-11-05 652 3ee7be9e10dd5f7 Rafael J. Wysocki 2025-03-06 653 em_table = rcu_dereference_protected(dev->em_pd->em_table, 3ee7be9e10dd5f7 Rafael J. Wysocki 2025-03-06 654 lockdep_is_held(&em_pd_mutex)); 3ee7be9e10dd5f7 Rafael J. Wysocki 2025-03-06 655 em_cpufreq_update_efficiencies(dev, em_table->state); e458716a92b57f8 Vincent Donnefort 2021-09-08 656 1bc138c62295997 Lukasz Luba 2020-06-10 657 em_debug_create_pd(dev); 1bc138c62295997 Lukasz Luba 2020-06-10 658 dev_info(dev, "EM: created perf domain\n"); 27871f7a8a341ef Quentin Perret 2018-12-03 659 27871f7a8a341ef Quentin Perret 2018-12-03 660 unlock: 27871f7a8a341ef Quentin Perret 2018-12-03 661 mutex_unlock(&em_pd_mutex); e3f1164fc9ee843 Lukasz Luba 2024-02-08 662 27871f7a8a341ef Quentin Perret 2018-12-03 663 return ret; 27871f7a8a341ef Quentin Perret 2018-12-03 664 } e0423541477dfb6 Rafael J. Wysocki 2025-09-05 665 EXPORT_SYMBOL_GPL(em_dev_register_pd_no_update); 7d9895c7fbfc9c7 Lukasz Luba 2020-05-27 666 :::::: The code at line 649 was first introduced by commit :::::: 91362463114eb63ead5f02c11d58c46064c339e7 PM: EM: Use the new .get_cost() callback while registering EM :::::: TO: Lukasz Luba <[email protected]> :::::: CC: Rafael J. Wysocki <[email protected]> -- 0-DAY CI Kernel Test Service https://github.com/intel/lkp-tests/wiki