tree 18c5b73f6d8f2a8feb85b81639ca7773b0eb9b0b
parent 269b04a50992d8defab869079049ecfc60b6b3e5
author David E. Box <david.e.box@linux.intel.com> 1616185124 -0700
committer Hans de Goede <hdegoede@redhat.com> 1616532614 +0100

platform/x86: intel_pmc_core: Ignore GBE LTR on Tiger Lake platforms

Due to a HW limitation, the Latency Tolerance Reporting (LTR) value
programmed in the Tiger Lake GBE controller is not large enough to allow
the platform to enter Package C10, which in turn prevents the platform from
achieving its low power target during suspend-to-idle.  Ignore the GBE LTR
value on Tiger Lake. LTR ignore functionality is currently performed solely
by a debugfs write call. Split out the LTR code into its own function that
can be called by both the debugfs writer and by this work around.

Signed-off-by: David E. Box <david.e.box@linux.intel.com>
Reviewed-by: Sasha Neftin <sasha.neftin@intel.com>
Cc: intel-wired-lan@lists.osuosl.org
Reviewed-by: Rajneesh Bhardwaj <irenic.rajneesh@gmail.com>
Link: https://lore.kernel.org/r/20210319201844.3305399-2-david.e.box@linux.intel.com
Signed-off-by: Hans de Goede <hdegoede@redhat.com>