In XE, display runtime suspend / resume routines are called only
if d3cold is allowed. This makes the driver unable to detect any
HPDs once the device goes into runtime suspend state in platforms
like LNL. Update the display runtime suspend / resume routines
to include HPD polling regardless of d3cold status.
While xe_display_pm_suspend/resume() performs steps during runtime
suspend/resume that shouldn't happen, like suspending MST and they
are missing other steps like enabling DC9, this patchset is meant
to keep the current behavior wrt. these, leaving the corresponding
updates for a follow-up
v2: have a separate function for display runtime s/r (Rodrigo)
v3: better streamlining of system s/r and runtime s/r calls (Imre)
v4: rebased
Reviewed-by: Arun R Murthy <arun.r.murthy@intel.com>
Signed-off-by: Vinod Govindapillai <vinod.govindapillai@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240823112148.327015-4-vinod.govindapillai@intel.com
Prepare power-well and DC handling for a full power
lost during D3Cold, then sanitize it upon D3->D0.
Otherwise we get a bunch of state mismatch.
Ideally we could leave DC9 enabled and wouldn't need
to move DC9->DC0 on every runtime resume, however,
the disable_DC is part of the power-well checks and
intrinsic to the dc_off power well. In the future that
can be detangled so we can have even bigger power savings.
But for now, let's focus on getting a D3Cold, which saves
much more power by itself.
v2: create new functions to avoid full-suspend-resume path,
which would result in a deadlock between xe_gem_fault and the
modeset-ioctl.
v3: Only avoid the full modeset to avoid the race, for a more
robust suspend-resume.
Cc: Anshuman Gupta <anshuman.gupta@intel.com>
Cc: Uma Shankar <uma.shankar@intel.com>
Tested-by: Francois Dugast <francois.dugast@intel.com>
Reviewed-by: Anshuman Gupta <anshuman.gupta@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240522170105.327472-5-rodrigo.vivi@intel.com
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
