iwlwifi: remove power-wasting calls to apm_ops.init()

To save power, don't run apm_ops.init() until needed at "up" time.

EEPROM (5000 and earlier devices) may be read without running apm_ops.init(),
but OTP reads (6000 and newer devices) require a powered-up chip.
Therefore, remove apm_ops.init() from the general path in XXXX_pci_probe(),
and call it only if device uses OTP.  Once done with OTP read, call
apm_ops.stop() to reset chip and save power until "up" time comes around.

NOTE:  This patch depends on removal of priv->lock from iwl_apm_stop();
lock does not get initialized until later in flow.  See patch
"remove unneeded locks from apm_stop()".

Signed-off-by: Ben Cahill <ben.m.cahill@intel.com>
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

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

@@ -3113,12 +3113,6 @@ static int iwl_pci_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 		goto out_iounmap;
 	}
 
-	/* amp init */
-	err = priv->cfg->ops->lib->apm_ops.init(priv);
-	if (err < 0) {
-		IWL_ERR(priv, "Failed to init APMG\n");
-		goto out_iounmap;
-	}
 	/*****************
 	 * 4. Read EEPROM
 	 *****************/

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

@@ -533,6 +533,10 @@ int iwl_eeprom_init(struct iwl_priv *priv)
 		goto err;
 	}
 	if (priv->nvm_device_type == NVM_DEVICE_TYPE_OTP) {
+
+		/* OTP reads require powered-up chip */
+		priv->cfg->ops->lib->apm_ops.init(priv);
+
 		ret = iwl_init_otp_access(priv);
 		if (ret) {
 			IWL_ERR(priv, "Failed to initialize OTP access.\n");
@@ -563,6 +567,13 @@ int iwl_eeprom_init(struct iwl_priv *priv)
 			e[cache_addr / 2] = eeprom_data;
 			cache_addr += sizeof(u16);
 		}
+
+		/*
+		 * Now that OTP reads are complete, reset chip to save
+		 *   power until we load uCode during "up".
+		 */
+		priv->cfg->ops->lib->apm_ops.stop(priv);
+
 	} else {
 		/* eeprom is an array of 16bit values */
 		for (addr = 0; addr < sz; addr += sizeof(u16)) {

drivers/net/wireless/iwlwifi/iwl3945-base.c

@@ -4000,13 +4000,6 @@ static int iwl3945_pci_probe(struct pci_dev *pdev, const struct pci_device_id *e
 	 */
 	spin_lock_init(&priv->reg_lock);
 
-	/* amp init */
-	err = priv->cfg->ops->lib->apm_ops.init(priv);
-	if (err < 0) {
-		IWL_DEBUG_INFO(priv, "Failed to init the card\n");
-		goto out_iounmap;
-	}
-
 	/***********************
 	 * 4. Read EEPROM
 	 * ********************/