iwlwifi: pcie: properly reset the device

We were toggling the wrong bit when we reset the device,
fix that. Moreover, since the reset can take time, we need
to wait before we set the rfkill interrupt. Not doing so
can be racy since the driver is enabling the rfkill
interrupt while the device is resetting which will clear
all the registers including the CSR_INT_MASK.
This can basically lead to a situation where we don't
enable the rfkill interrupt. If that happens, the user will
not be able to re-enable the device when de-asserting
rfkill.

This scenario happened to the submitter of:
https://bugzilla.kernel.org/show_bug.cgi?id=87191

Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>

Author: egrumbach

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

@@ -942,7 +942,8 @@ static void iwl_trans_pcie_stop_device(struct iwl_trans *trans)
 	spin_unlock(&trans_pcie->irq_lock);
 
 	/* stop and reset the on-board processor */
-	iwl_write32(trans, CSR_RESET, CSR_RESET_REG_FLAG_NEVO_RESET);
+	iwl_write32(trans, CSR_RESET, CSR_RESET_REG_FLAG_SW_RESET);
+	udelay(20);
 
 	/* clear all status bits */
 	clear_bit(STATUS_SYNC_HCMD_ACTIVE, &trans->status);