igc: disable L1.2 PCI-E link substate to avoid performance issue

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[ Upstream commit 0325143b59 ]

I226 devices advertise support for the PCI-E link L1.2 substate. However,
due to a hardware limitation, the exit latency from this low-power state
is longer than the packet buffer can tolerate under high traffic
conditions. This can lead to packet loss and degraded performance.

To mitigate this, disable the L1.2 substate. The increased power draw
between L1.1 and L1.2 is insignificant.

Fixes: 4354621173 ("igc: Add new device ID's")
Link: https://lore.kernel.org/intel-wired-lan/15248b4f-3271-42dd-8e35-02bfc92b25e1@intel.com
Signed-off-by: Vitaly Lifshits <vitaly.lifshits@intel.com>
Reviewed-by: Aleksandr Loktionov <aleksandr.loktionov@intel.com>
Tested-by: Mor Bar-Gabay <morx.bar.gabay@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

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Vitaly Lifshits 2025-06-11 15:52:54 +03:00 • committed by Greg Kroah-Hartman

parent 9d32b2e20f

commit e540b65ff3

1 changed files with 10 additions and 0 deletions

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

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