RE: [PATCH] wifi: iwlwifi: use unique thermal zone type

[Korenblit, Miriam Rachel]

> -----Original Message-----
> From: Jiajia Liu <liujiajia@xxxxxxxxxx>
> Sent: Thursday, March 12, 2026 3:41 AM
> To: Korenblit, Miriam Rachel <miriam.rachel.korenblit@xxxxxxxxx>; Berg,
> Benjamin <benjamin.berg@xxxxxxxxx>; Berg, Johannes
> <johannes.berg@xxxxxxxxx>; linux-wireless@xxxxxxxxxxxxxxx; linux-
> kernel@xxxxxxxxxxxxxxx
> Cc: Jiajia Liu <liujiajia@xxxxxxxxxx>
> Subject: [PATCH] wifi: iwlwifi: use unique thermal zone type
> 
> Unloading iwlmld or iwlmvm can trigger hung task when two devices using
> iwlmvm and iwlmld respectively on one setup. Their thermal zones have the
> same type and share the same hwmon device created by the first zone. The
> second zone indirectly holds the first zone through hwmon and prevents the first
> zone from unregistering.
> Tested with AX211 (8086:7af0) and BE200 (8086:272b).
> 
> INFO: task modprobe:5295 blocked for more than 120 seconds.
>       Not tainted 7.0.0-rc2-up1 #2
> Call Trace:
>  __schedule+0x4df/0xfd0
>  schedule+0x27/0xd0
>  schedule_timeout+0xbd/0x100
>  __wait_for_common+0x97/0x1b0
>  ? __pfx_schedule_timeout+0x10/0x10
>  thermal_zone_device_unregister+0x173/0x1c0
>  iwl_mld_thermal_exit+0xbb/0xd0 [iwlmld]
>  iwl_op_mode_mld_stop+0x37/0x120 [iwlmld]
>  iwl_opmode_deregister+0xc0/0x160 [iwlwifi]
>  __do_sys_delete_module+0x1b5/0x320
> 
> Signed-off-by: Jiajia Liu <liujiajia@xxxxxxxxxx>
> ---
>  drivers/net/wireless/intel/iwlwifi/iwl-utils.c   | 10 ++++++++++
>  drivers/net/wireless/intel/iwlwifi/iwl-utils.h   |  4 ++++
>  drivers/net/wireless/intel/iwlwifi/mld/thermal.c |  4 ++--
>  drivers/net/wireless/intel/iwlwifi/mvm/tt.c      |  6 ++++--
>  4 files changed, 20 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/net/wireless/intel/iwlwifi/iwl-utils.c
> b/drivers/net/wireless/intel/iwlwifi/iwl-utils.c
> index d503544fda40..fe5fa5e59664 100644
> --- a/drivers/net/wireless/intel/iwlwifi/iwl-utils.c
> +++ b/drivers/net/wireless/intel/iwlwifi/iwl-utils.c
> @@ -193,3 +193,13 @@ s8 iwl_average_neg_dbm(const u8 *neg_dbm_values,
> u8 len)
>  	return clamp(average_magnitude - i, -128, 0);  }
> IWL_EXPORT_SYMBOL(iwl_average_neg_dbm);
> +
> +#ifdef CONFIG_THERMAL
> +u8 iwl_thermal_zone_get_id(void)
> +{
> +	static atomic_t counter = ATOMIC_INIT(0);
> +
> +	return atomic_inc_return(&counter) & 0xFF; }
> +IWL_EXPORT_SYMBOL(iwl_thermal_zone_get_id);
> +#endif
> diff --git a/drivers/net/wireless/intel/iwlwifi/iwl-utils.h
> b/drivers/net/wireless/intel/iwlwifi/iwl-utils.h
> index 5172035e4d26..84a4543fd290 100644
> --- a/drivers/net/wireless/intel/iwlwifi/iwl-utils.h
> +++ b/drivers/net/wireless/intel/iwlwifi/iwl-utils.h
> @@ -55,4 +55,8 @@ u32 iwl_find_ie_offset(u8 *beacon, u8 eid, u32 frame_size)
> 
>  s8 iwl_average_neg_dbm(const u8 *neg_dbm_values, u8 len);
> 
> +#ifdef CONFIG_THERMAL
> +u8 iwl_thermal_zone_get_id(void);
> +#endif
> +
>  #endif /* __iwl_utils_h__ */
> diff --git a/drivers/net/wireless/intel/iwlwifi/mld/thermal.c
> b/drivers/net/wireless/intel/iwlwifi/mld/thermal.c
> index f8a8c35066be..500028a4dbd3 100644
> --- a/drivers/net/wireless/intel/iwlwifi/mld/thermal.c
> +++ b/drivers/net/wireless/intel/iwlwifi/mld/thermal.c
> @@ -5,6 +5,7 @@
>  #ifdef CONFIG_THERMAL
>  #include <linux/sort.h>
>  #include <linux/thermal.h>
> +#include "iwl-utils.h"
>  #endif
> 
>  #include "fw/api/phy.h"
> @@ -243,7 +244,6 @@ static void iwl_mld_thermal_zone_register(struct
> iwl_mld *mld)  {
>  	int ret;
>  	char name[16];
> -	static atomic_t counter = ATOMIC_INIT(0);
>  	struct thermal_trip trips[IWL_MAX_DTS_TRIPS] = {
>  		[0 ... IWL_MAX_DTS_TRIPS - 1] = {
>  			.temperature = THERMAL_TEMP_INVALID, @@ -254,7
> +254,7 @@ static void iwl_mld_thermal_zone_register(struct iwl_mld *mld)
> 
>  	BUILD_BUG_ON(ARRAY_SIZE(name) >= THERMAL_NAME_LENGTH);
> 
> -	sprintf(name, "iwlwifi_%u", atomic_inc_return(&counter) & 0xFF);
Any reason not to have iwlmld (and iwlmvm in mvm) instead of a shared counter?

> +	sprintf(name, "iwlwifi_%u", iwl_thermal_zone_get_id());
>  	mld->tzone =
>  		thermal_zone_device_register_with_trips(name, trips,
>  							IWL_MAX_DTS_TRIPS,
> diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/tt.c
> b/drivers/net/wireless/intel/iwlwifi/mvm/tt.c
> index 53bab21ebae2..ea8e616174db 100644
> --- a/drivers/net/wireless/intel/iwlwifi/mvm/tt.c
> +++ b/drivers/net/wireless/intel/iwlwifi/mvm/tt.c
> @@ -7,6 +7,9 @@
>  #include <linux/sort.h>
> 
>  #include "mvm.h"
> +#ifdef CONFIG_THERMAL
> +#include "iwl-utils.h"
> +#endif
> 
>  #define IWL_MVM_NUM_CTDP_STEPS		20
>  #define IWL_MVM_MIN_CTDP_BUDGET_MW	150
> @@ -652,7 +655,6 @@ static void iwl_mvm_thermal_zone_register(struct
> iwl_mvm *mvm)  {
>  	int i, ret;
>  	char name[16];
> -	static atomic_t counter = ATOMIC_INIT(0);
> 
>  	if (!iwl_mvm_is_tt_in_fw(mvm)) {
>  		mvm->tz_device.tzone = NULL;
> @@ -662,7 +664,7 @@ static void iwl_mvm_thermal_zone_register(struct
> iwl_mvm *mvm)
> 
>  	BUILD_BUG_ON(ARRAY_SIZE(name) >= THERMAL_NAME_LENGTH);
> 
> -	sprintf(name, "iwlwifi_%u", atomic_inc_return(&counter) & 0xFF);
> +	sprintf(name, "iwlwifi_%u", iwl_thermal_zone_get_id());
>  	/*
>  	 * 0 is a valid temperature,
>  	 * so initialize the array with S16_MIN which invalid temperature
> --
> 2.53.0