igc: fix disabling L1.2 PCI-E link substate on I226 on init

[ Upstream commit 1468c1f ]

Device ID comparison in igc_is_device_id_i226 is performed before
the ID is set, resulting in always failing check on init.

Before the patch:
* L1.2 is not disabled on init
* L1.2 is properly disabled after suspend-resume cycle

With the patch:
* L1.2 is properly disabled both on init and after suspend-resume

How to test:
Connect to the 1G link with 300+ mbit/s Internet speed, and run
the download speed test, such as:

    curl -o /dev/null http://speedtest.selectel.ru/1GB

Without L1.2 disabled, the speed would be no more than ~200 mbit/s.
With L1.2 disabled, the speed would reach 1 gbit/s.
Note: it's required that the latency between your host and the remote
be around 3-5 ms, the test inside LAN (<1 ms latency) won't trigger the
issue.

Link: https://lore.kernel.org/intel-wired-lan/15248b4f-3271-42dd-8e35-02bfc92b25e1@intel.com
Fixes: 0325143 ("igc: disable L1.2 PCI-E link substate to avoid performance issue")
Signed-off-by: ValdikSS <iam@valdikss.org.ru>
Reviewed-by: Vitaly Lifshits <vitaly.lifshits@intel.com>
Reviewed-by: Paul Menzel <pmenzel@molgen.mpg.de>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
Link: https://patch.msgid.link/20250819222000.3504873-6-anthony.l.nguyen@intel.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

Author: ValdikSS

drivers/net/ethernet/intel/igc/igc_main.c

@@ -6553,6 +6553,13 @@ static int igc_probe(struct pci_dev *pdev,
 	adapter->port_num = hw->bus.func;
 	adapter->msg_enable = netif_msg_init(debug, DEFAULT_MSG_ENABLE);
 
+	/* PCI config space info */
+	hw->vendor_id = pdev->vendor;
+	hw->device_id = pdev->device;
+	hw->revision_id = pdev->revision;
+	hw->subsystem_vendor_id = pdev->subsystem_vendor;
+	hw->subsystem_device_id = pdev->subsystem_device;
+
 	/* Disable ASPM L1.2 on I226 devices to avoid packet loss */
 	if (igc_is_device_id_i226(hw))
 		pci_disable_link_state(pdev, PCIE_LINK_STATE_L1_2);
@@ -6577,13 +6584,6 @@ static int igc_probe(struct pci_dev *pdev,
 	netdev->mem_start = pci_resource_start(pdev, 0);
 	netdev->mem_end = pci_resource_end(pdev, 0);
 
-	/* PCI config space info */
-	hw->vendor_id = pdev->vendor;
-	hw->device_id = pdev->device;
-	hw->revision_id = pdev->revision;
-	hw->subsystem_vendor_id = pdev->subsystem_vendor;
-	hw->subsystem_device_id = pdev->subsystem_device;
-
 	/* Copy the default MAC and PHY function pointers */
 	memcpy(&hw->mac.ops, ei->mac_ops, sizeof(hw->mac.ops));
 	memcpy(&hw->phy.ops, ei->phy_ops, sizeof(hw->phy.ops));