i40e: Acquire NVM lock before reads on all devices

BugLink: http://bugs.launchpad.net/bugs/1764666

[ Upstream commit 96a39aed ]

Acquire NVM lock before reads on all devices.  Previously, locks were
only used for X722 and later.  Fixes an issue where simultaneous X710
NVM accesses were interfering with each other.

Change-ID: If570bb7acf958cef58725ec2a2011cead6f80638
Signed-off-by: Aaron Salter <aaron.k.salter@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Juerg Haefliger <juergh@canonical.com>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>

drivers/net/ethernet/intel/i40e/i40e_nvm.c

@@ -292,14 +292,14 @@ i40e_status i40e_read_nvm_word(struct i40e_hw *hw, u16 offset,
 {
 	enum i40e_status_code ret_code = 0;
 
-	if (hw->flags & I40E_HW_FLAG_AQ_SRCTL_ACCESS_ENABLE) {
-		ret_code = i40e_acquire_nvm(hw, I40E_RESOURCE_READ);
-		if (!ret_code) {
+	ret_code = i40e_acquire_nvm(hw, I40E_RESOURCE_READ);
+	if (!ret_code) {
+		if (hw->flags & I40E_HW_FLAG_AQ_SRCTL_ACCESS_ENABLE) {
 			ret_code = i40e_read_nvm_word_aq(hw, offset, data);
-			i40e_release_nvm(hw);
+		} else {
+			ret_code = i40e_read_nvm_word_srctl(hw, offset, data);
 		}
-	} else {
-		ret_code = i40e_read_nvm_word_srctl(hw, offset, data);
+		i40e_release_nvm(hw);
 	}
 	return ret_code;
 }