[PATCH 0/2] Check if CSME is available before initializing PXP

[Daniele Ceraolo Spurio]

To support PXP, i915 needs to interface with CSME, which is done via the
component interface. However, BIOS/Coreboot can hide the CSME device,
which leads to i915 timing out waiting for the component to bind. While
PXP failing to initialize is a supported scenario (and there are several
possible ways for it to happen), the particular case where the CSME is
not available at all is something we can easily detect in the driver
and therefore avoid entirely, which means userspace doesn't need to
handle the error in this case.

Given that mei_me owns the CSME, the check for the device availability
is added to that driver and exported, with i915 calling it. The plan is
to merge both patches via the drm-intel tree.

Cc: Rodrigo Vivi <rodrigo.vivi at intel.com>
Cc: Alexander Usyskin <alexander.usyskin at intel.com>
Cc: Alan Previn <alan.previn.teres.alexis at intel.com>
Cc: Greg Kroah-Hartman <gregkh at linuxfoundation.org>

Daniele Ceraolo Spurio (2):
  mei: me: Add exported function to check ME device availabiliy
  drm/i915/pxp: Do not support PXP if CSME is not available

 drivers/gpu/drm/i915/i915_module.c   |  1 +
 drivers/gpu/drm/i915/pxp/intel_pxp.c |  5 +++++
 drivers/misc/mei/pci-me.c            | 17 +++++++++++++++++
 include/linux/mei_me.h               | 20 ++++++++++++++++++++
 4 files changed, 43 insertions(+)
 create mode 100644 include/linux/mei_me.h

-- 
2.43.0