wifi: iwlwifi: mvm: Use the sync timepoint API in suspend

When starting the suspend flow, HOST_D3_START triggers an _async_
firmware dump collection for debugging purposes. The async worker
may race with suspend flow and fail to get NIC access, resulting in
the following warning:
"Timeout waiting for hardware access (CSR_GP_CNTRL 0xffffffff)"

Fix this by switching to the sync version to ensure the dump
completes before proceeding with the suspend flow, avoiding
potential race issues.

Signed-off-by: Daniel Gabay <[email protected]>
Signed-off-by: Miri Korenblit <[email protected]>
Link: https://patch.msgid.link/20241010140328.9aae318cd593.I4b322009f39489c0b1d8893495c887870f73ed9c@changeid
Signed-off-by: Johannes Berg <[email protected]>

Author: gabayd

drivers/net/wireless/intel/iwlwifi/fw/init.c

@@ -39,10 +39,12 @@ void iwl_fw_runtime_init(struct iwl_fw_runtime *fwrt, struct iwl_trans *trans,
 }
 IWL_EXPORT_SYMBOL(iwl_fw_runtime_init);
 
+/* Assumes the appropriate lock is held by the caller */
 void iwl_fw_runtime_suspend(struct iwl_fw_runtime *fwrt)
 {
 	iwl_fw_suspend_timestamp(fwrt);
-	iwl_dbg_tlv_time_point(fwrt, IWL_FW_INI_TIME_POINT_HOST_D3_START, NULL);
+	iwl_dbg_tlv_time_point_sync(fwrt, IWL_FW_INI_TIME_POINT_HOST_D3_START,
+				    NULL);
 }
 IWL_EXPORT_SYMBOL(iwl_fw_runtime_suspend);
 

drivers/net/wireless/intel/iwlwifi/mvm/d3.c

@@ -1398,7 +1398,9 @@ int iwl_mvm_suspend(struct ieee80211_hw *hw, struct cfg80211_wowlan *wowlan)
 
 	iwl_mvm_pause_tcm(mvm, true);
 
+	mutex_lock(&mvm->mutex);
 	iwl_fw_runtime_suspend(&mvm->fwrt);
+	mutex_unlock(&mvm->mutex);
 
 	return __iwl_mvm_suspend(hw, wowlan, false);
 }