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

[ Upstream commit 1468c1f9 ]

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: 0325143b ("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>