iwlwifi: pcie: retake ownership after reset

In most cases, unless shutting down the NIC, we really need
to retake ownership after doing a software reset of the NIC.
Encode that into the API so we "automatically" do it, even
in case of workarounds, and don't keep forgetting it like a
few of the places we have did.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Link: https://lore.kernel.org/r/iwlwifi.20211204174545.458f9d98ac21.I40b9a22df1ab8178cc838fc83d5190e689dfac6a@changeidSigned-off-by: Luca Coelho <luciano.coelho@intel.com>

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

@@ -212,7 +212,9 @@ static void iwl_fwrt_dump_lmac_error_log(struct iwl_fw_runtime *fwrt, u8 lmac_nu
 		IWL_ERR(trans, "HW error, resetting before reading\n");
 
 		/* reset the device */
-		iwl_trans_sw_reset(trans);
+		err = iwl_trans_sw_reset(trans, true);
+		if (err)
+			return;
 
 		err = iwl_finish_nic_init(trans);
 		if (err)

drivers/net/wireless/intel/iwlwifi/iwl-trans.h

@@ -593,7 +593,7 @@ struct iwl_trans_ops {
 	void (*configure)(struct iwl_trans *trans,
 			  const struct iwl_trans_config *trans_cfg);
 	void (*set_pmi)(struct iwl_trans *trans, bool state);
-	void (*sw_reset)(struct iwl_trans *trans);
+	int (*sw_reset)(struct iwl_trans *trans, bool retake_ownership);
 	bool (*grab_nic_access)(struct iwl_trans *trans);
 	void (*release_nic_access)(struct iwl_trans *trans);
 	void (*set_bits_mask)(struct iwl_trans *trans, u32 reg, u32 mask,
@@ -1386,10 +1386,12 @@ static inline void iwl_trans_set_pmi(struct iwl_trans *trans, bool state)
 		trans->ops->set_pmi(trans, state);
 }
 
-static inline void iwl_trans_sw_reset(struct iwl_trans *trans)
+static inline int iwl_trans_sw_reset(struct iwl_trans *trans,
+				     bool retake_ownership)
 {
 	if (trans->ops->sw_reset)
-		trans->ops->sw_reset(trans);
+		return trans->ops->sw_reset(trans, retake_ownership);
+	return 0;
 }
 
 static inline void

drivers/net/wireless/intel/iwlwifi/pcie/trans-gen2.c

@@ -81,7 +81,7 @@ static void iwl_pcie_gen2_apm_stop(struct iwl_trans *trans, bool op_mode_leave)
 	/* Stop device's DMA activity */
 	iwl_pcie_apm_stop_master(trans);
 
-	iwl_trans_sw_reset(trans);
+	iwl_trans_sw_reset(trans, false);
 
 	/*
 	 * Clear "initialization complete" bit to move adapter from
@@ -166,7 +166,8 @@ void _iwl_trans_pcie_gen2_stop_device(struct iwl_trans *trans)
 	/* Stop the device, and put it in low power state */
 	iwl_pcie_gen2_apm_stop(trans, false);
 
-	iwl_trans_sw_reset(trans);
+	/* re-take ownership to prevent other users from stealing the device */
+	iwl_trans_sw_reset(trans, true);
 
 	/*
 	 * Upon stop, the IVAR table gets erased, so msi-x won't
@@ -196,9 +197,6 @@ void _iwl_trans_pcie_gen2_stop_device(struct iwl_trans *trans)
 	 * interrupt
 	 */
 	iwl_enable_rfkill_int(trans);
-
-	/* re-take ownership to prevent other users from stealing the device */
-	iwl_pcie_prepare_card_hw(trans);
 }
 
 void iwl_trans_pcie_gen2_stop_device(struct iwl_trans *trans)

drivers/net/wireless/intel/iwlwifi/pcie/trans.c

@@ -127,7 +127,8 @@ void iwl_trans_pcie_dump_regs(struct iwl_trans *trans)
 	kfree(buf);
 }
 
-static void iwl_trans_pcie_sw_reset(struct iwl_trans *trans)
+static int iwl_trans_pcie_sw_reset(struct iwl_trans *trans,
+				   bool retake_ownership)
 {
 	/* Reset entire device - do controller reset (results in SHRD_HW_RST) */
 	if (trans->trans_cfg->device_family >= IWL_DEVICE_FAMILY_BZ)
@@ -137,6 +138,11 @@ static void iwl_trans_pcie_sw_reset(struct iwl_trans *trans)
 		iwl_set_bit(trans, CSR_RESET,
 			    CSR_RESET_REG_FLAG_SW_RESET);
 	usleep_range(5000, 6000);
+
+	if (retake_ownership)
+		return iwl_pcie_prepare_card_hw(trans);
+
+	return 0;
 }
 
 static void iwl_pcie_free_fw_monitor(struct iwl_trans *trans)
@@ -382,9 +388,11 @@ static void iwl_pcie_apm_lp_xtal_enable(struct iwl_trans *trans)
 	__iwl_trans_pcie_set_bit(trans, CSR_GP_CNTRL,
 				 CSR_GP_CNTRL_REG_FLAG_XTAL_ON);
 
-	iwl_trans_pcie_sw_reset(trans);
+	ret = iwl_trans_pcie_sw_reset(trans, true);
+
+	if (!ret)
+		ret = iwl_finish_nic_init(trans);
 
-	ret = iwl_finish_nic_init(trans);
 	if (WARN_ON(ret)) {
 		/* Release XTAL ON request */
 		__iwl_trans_pcie_clear_bit(trans, CSR_GP_CNTRL,
@@ -409,7 +417,10 @@ static void iwl_pcie_apm_lp_xtal_enable(struct iwl_trans *trans)
 				 apmg_xtal_cfg_reg |
 				 SHR_APMG_XTAL_CFG_XTAL_ON_REQ);
 
-	iwl_trans_pcie_sw_reset(trans);
+	ret = iwl_trans_pcie_sw_reset(trans, true);
+	if (ret)
+		IWL_ERR(trans,
+			"iwl_pcie_apm_lp_xtal_enable: failed to retake NIC ownership\n");
 
 	/* Enable LP XTAL by indirect access through CSR */
 	apmg_gp1_reg = iwl_trans_pcie_read_shr(trans, SHR_APMG_GP1_REG);
@@ -515,7 +526,7 @@ static void iwl_pcie_apm_stop(struct iwl_trans *trans, bool op_mode_leave)
 		return;
 	}
 
-	iwl_trans_pcie_sw_reset(trans);
+	iwl_trans_pcie_sw_reset(trans, false);
 
 	/*
 	 * Clear "initialization complete" bit to move adapter from
@@ -1261,7 +1272,8 @@ static void _iwl_trans_pcie_stop_device(struct iwl_trans *trans)
 	/* Stop the device, and put it in low power state */
 	iwl_pcie_apm_stop(trans, false);
 
-	iwl_trans_pcie_sw_reset(trans);
+	/* re-take ownership to prevent other users from stealing the device */
+	iwl_trans_pcie_sw_reset(trans, true);
 
 	/*
 	 * Upon stop, the IVAR table gets erased, so msi-x won't
@@ -1291,9 +1303,6 @@ static void _iwl_trans_pcie_stop_device(struct iwl_trans *trans)
 	 * interrupt
 	 */
 	iwl_enable_rfkill_int(trans);
-
-	/* re-take ownership to prevent other users from stealing the device */
-	iwl_pcie_prepare_card_hw(trans);
 }
 
 void iwl_pcie_synchronize_irqs(struct iwl_trans *trans)
@@ -1802,9 +1811,7 @@ static int iwl_pcie_gen2_force_power_gating(struct iwl_trans *trans)
 	iwl_clear_bits_prph(trans, HPM_HIPM_GEN_CFG,
 			    HPM_HIPM_GEN_CFG_CR_FORCE_ACTIVE);
 
-	iwl_trans_pcie_sw_reset(trans);
-
-	return 0;
+	return iwl_trans_pcie_sw_reset(trans, true);
 }
 
 static int _iwl_trans_pcie_start_hw(struct iwl_trans *trans)
@@ -1824,7 +1831,9 @@ static int _iwl_trans_pcie_start_hw(struct iwl_trans *trans)
 	if (err)
 		return err;
 
-	iwl_trans_pcie_sw_reset(trans);
+	err = iwl_trans_pcie_sw_reset(trans, true);
+	if (err)
+		return err;
 
 	if (trans->trans_cfg->device_family == IWL_DEVICE_FAMILY_22000 &&
 	    trans->trans_cfg->integrated) {