iwlwifi: mvm: allow preventing dummy notifications

The firwmare now allows the driver to disable dummy
notifications. These notifications sent by the firmware
are an overhead for slow buses. They are still useful for
fast buses.
Add a hardware switch to prevent these notifications only
on devices that work on slow buses.
Signed-off-by: Eran <eran.harary@intel.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>

drivers/net/wireless/iwlwifi/iwl-8000.c

@@ -144,6 +144,7 @@ const struct iwl_cfg iwl8260_2ac_sdio_cfg = {
 	.nvm_calib_ver = IWL8000_TX_POWER_VERSION,
 	.default_nvm_file = DEFAULT_NVM_FILE_FAMILY_8000,
 	.max_rx_agg_size = MAX_RX_AGG_SIZE_8260_SDIO,
+	.disable_dummy_notification = true,
 };
 
 MODULE_FIRMWARE(IWL8000_MODULE_FIRMWARE(IWL8000_UCODE_API_OK));

drivers/net/wireless/iwlwifi/iwl-config.h

@@ -282,6 +282,7 @@ struct iwl_cfg {
 	bool no_power_up_nic_in_init;
 	const char *default_nvm_file;
 	unsigned int max_rx_agg_size;
+	bool disable_dummy_notification;
 };
 
 /*

drivers/net/wireless/iwlwifi/iwl-fw.h

@@ -127,6 +127,7 @@ enum iwl_ucode_tlv_flag {
  * @IWL_UCODE_TLV_API_CSA_FLOW: ucode can do unbind-bind flow for CSA.
  * @IWL_UCODE_TLV_API_DISABLE_STA_TX: ucode supports tx_disable bit.
  * @IWL_UCODE_TLV_API_LMAC_SCAN: This ucode uses LMAC unified scan API.
+ * @IWL_UCODE_TLV_API_SF_NO_DUMMY_NOTIF: ucode supports disabling dummy notif.
  * @IWL_UCODE_TLV_API_FRAGMENTED_SCAN: This ucode supports active dwell time
  *	longer than the passive one, which is essential for fragmented scan.
  */
@@ -137,6 +138,7 @@ enum iwl_ucode_tlv_api {
 	IWL_UCODE_TLV_API_CSA_FLOW		= BIT(4),
 	IWL_UCODE_TLV_API_DISABLE_STA_TX	= BIT(5),
 	IWL_UCODE_TLV_API_LMAC_SCAN		= BIT(6),
+	IWL_UCODE_TLV_API_SF_NO_DUMMY_NOTIF	= BIT(7),
 	IWL_UCODE_TLV_API_FRAGMENTED_SCAN	= BIT(8),
 };
 

drivers/net/wireless/iwlwifi/mvm/fw-api.h

@@ -1601,6 +1601,8 @@ enum iwl_sf_scenario {
 
 #define SF_LONG_DELAY_AGING_TIMER 1000000	/* 1 Sec */
 
+#define SF_CFG_DUMMY_NOTIF_OFF	BIT(16)
+
 /**
  * Smart Fifo configuration command.
  * @state: smart fifo state, types listed in enum %iwl_sf_sate.

drivers/net/wireless/iwlwifi/mvm/sf.c

@@ -179,6 +179,10 @@ static int iwl_mvm_sf_config(struct iwl_mvm *mvm, u8 sta_id,
 	struct ieee80211_sta *sta;
 	int ret = 0;
 
+	if (mvm->fw->ucode_capa.api[0] & IWL_UCODE_TLV_API_SF_NO_DUMMY_NOTIF &&
+	    mvm->cfg->disable_dummy_notification)
+		sf_cmd.state |= cpu_to_le32(SF_CFG_DUMMY_NOTIF_OFF);
+
 	/*
 	 * If an associated AP sta changed its antenna configuration, the state
 	 * will remain FULL_ON but SF parameters need to be reconsidered.