[PATCH 3/4] wifi: ath12k: unregister the thermal devices of a radio only once

[Vladyslav Tymoshchuk <tvlad744@gmail.com>]

ath12k_core_reconfigure_on_crash() calls ath12k_thermal_unregister(),
and the devices are registered again only when the start that follows
reaches ath12k_core_pdev_create(). If it does not, because the firmware
crashes again or the start fails earlier, the next restart unregisters
the devices a second time:

  Unable to handle kernel NULL pointer dereference at virtual address 0000000000000050
  Workqueue: ath12k_wq ath12k_core_restart [ath12k]
  pc : hwmon_device_unregister+0x24/0x90
  lr : ath12k_thermal_unregister+0x7c/0xf4 [ath12k]
  Call trace:
   hwmon_device_unregister+0x24/0x90 (P)
   ath12k_thermal_unregister+0x7c/0xf4 [ath12k]
   ath12k_core_restart+0x3c/0x210 [ath12k]

Skip the radios that have nothing registered.

Fixes: 151322bccdbd ("wifi: ath12k: add basic hwmon temperature reporting")
Signed-off-by: Vladyslav Tymoshchuk <tvlad744@gmail.com>
---
 drivers/net/wireless/ath/ath12k/thermal.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/wireless/ath/ath12k/thermal.c b/drivers/net/wireless/ath/ath12k/thermal.c
index 97fc49c40ac1..7707ae4eb683 100644
--- a/drivers/net/wireless/ath/ath12k/thermal.c
+++ b/drivers/net/wireless/ath/ath12k/thermal.c
@@ -257,7 +257,7 @@ static void ath12k_thermal_cleanup_radio(struct ath12k_base *ab, int i)
 	struct ath12k *ar;
 
 	ar = ab->pdevs[i].ar;
-	if (!ar)
+	if (!ar || !ar->thermal.cdev)
 		return;
 
 	hwmon_device_unregister(ar->thermal.hwmon_dev);
-- 
2.43.0