From 83128399f3b4926ab73ce8e5081ce6595e9230e9 Mon Sep 17 00:00:00 2001 From: Benjamin Berg Date: Tue, 6 May 2025 22:40:58 +0300 Subject: [PATCH] wifi: iwlwifi: mld: call thermal exit without wiphy lock held The driver must not hold the wiphy mutex when unregistering the thermal devices. Do not hold the lock for the call to iwl_mld_thermal_exit and only do a lock/unlock to cancel the ct_kill_exit_wk work. The problem is that iwl_mld_tzone_get_temp needs to take the wiphy lock while the thermal code is holding its own locks already. When unregistering the device, the reverse would happen as the driver was calling thermal_cooling_device_unregister with the wiphy mutex already held. It is not likely to trigger this deadlock as it can only happen if the thermal code is polling the temperature while the driver is being unloaded. However, lockdep reported it so fix it. Signed-off-by: Benjamin Berg Reviewed-by: Johannes Berg Link: https://patch.msgid.link/20250506194102.3407967-12-miriam.rachel.korenblit@intel.com Signed-off-by: Miri Korenblit --- drivers/net/wireless/intel/iwlwifi/mld/mld.c | 3 ++- drivers/net/wireless/intel/iwlwifi/mld/thermal.c | 4 ++++ 2 files changed, 6 insertions(+), 1 deletion(-) diff --git a/drivers/net/wireless/intel/iwlwifi/mld/mld.c b/drivers/net/wireless/intel/iwlwifi/mld/mld.c index 2c15af7b8768d..3e3af7d23b52a 100644 --- a/drivers/net/wireless/intel/iwlwifi/mld/mld.c +++ b/drivers/net/wireless/intel/iwlwifi/mld/mld.c @@ -489,8 +489,9 @@ iwl_op_mode_mld_stop(struct iwl_op_mode *op_mode) iwl_mld_ptp_remove(mld); iwl_mld_leds_exit(mld); - wiphy_lock(mld->wiphy); iwl_mld_thermal_exit(mld); + + wiphy_lock(mld->wiphy); iwl_mld_low_latency_stop(mld); iwl_mld_deinit_time_sync(mld); wiphy_unlock(mld->wiphy); diff --git a/drivers/net/wireless/intel/iwlwifi/mld/thermal.c b/drivers/net/wireless/intel/iwlwifi/mld/thermal.c index 3232b31f4b0e9..f8a8c35066beb 100644 --- a/drivers/net/wireless/intel/iwlwifi/mld/thermal.c +++ b/drivers/net/wireless/intel/iwlwifi/mld/thermal.c @@ -441,6 +441,8 @@ static u32 iwl_mld_ctdp_get_max_budget(struct iwl_mld *mld) void iwl_mld_thermal_initialize(struct iwl_mld *mld) { + lockdep_assert_not_held(&mld->wiphy->mtx); + wiphy_delayed_work_init(&mld->ct_kill_exit_wk, iwl_mld_exit_ctkill); mld->power_budget_mw = iwl_mld_ctdp_get_max_budget(mld); @@ -454,7 +456,9 @@ void iwl_mld_thermal_initialize(struct iwl_mld *mld) void iwl_mld_thermal_exit(struct iwl_mld *mld) { + wiphy_lock(mld->wiphy); wiphy_delayed_work_cancel(mld->wiphy, &mld->ct_kill_exit_wk); + wiphy_unlock(mld->wiphy); #ifdef CONFIG_THERMAL iwl_mld_cooling_device_unregister(mld); -- 2.50.1