drm/i915/pch: Save/restore PCH_PORT_HOTPLUG across suspend
At least on a Lenovo X220 the HPD bits of this are enabled at boot but
cleared after resume, which means plug interrupts stop working.
This also happens to fix DP displays re-lighting on resume. I'm quite
certain that's an accident: the first DP link train inevitably fails on
that machine, and it's only serendipity that we're getting multiple plug
interrupts and the second train works. But I shall take my victories
where I get them.
Signed-off-by: Adam Jackson <ajax@redhat.com>
Tested-by: Keith Packard <keithp@keithp.com>
Reviewed-by: Keith Packard <keithp@keithp.com>
Signed-off-by: Keith Packard <keithp@keithp.com>
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index ce7914c..e0d0e27 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -541,6 +541,7 @@
u32 savePIPEB_LINK_M1;
u32 savePIPEB_LINK_N1;
u32 saveMCHBAR_RENDER_STANDBY;
+ u32 savePCH_PORT_HOTPLUG;
struct {
/** Bridge to intel-gtt-ko */