drm/i915: add multi-threaded forcewake support
On IVB C0+ with newer BIOSes, the forcewake handshake has changed. There's
now a bitfield for different driver components to keep the GT powered
on. On Linux, we centralize forcewake handling in one place, so we
still just need a single bit, but we need to use the new registers if MT
forcewake is enabled.
This needs testing on affected machines. Please reply with your
tested-by if you had problems after a BIOS upgrade and this patch fixes
them.
v2: force MT mode. shift by 16
v3: set MT force wake bits then check ECOBUS
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=42923
Tested-by: Manoj Iyer <manoj.iyer@canonical.com>
Tested-by: Robert Hooker <robert.hooker@canonical.com>
Tested-by: Keith Packard <keithp@keithp.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Keith Packard <keithp@keithp.com>
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index e77a863..633c693 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -8491,6 +8491,28 @@
/* For FIFO watermark updates */
if (HAS_PCH_SPLIT(dev)) {
+ dev_priv->display.force_wake_get = __gen6_gt_force_wake_get;
+ dev_priv->display.force_wake_put = __gen6_gt_force_wake_put;
+
+ /* IVB configs may use multi-threaded forcewake */
+ if (IS_IVYBRIDGE(dev)) {
+ u32 ecobus;
+
+ mutex_lock(&dev->struct_mutex);
+ __gen6_gt_force_wake_mt_get(dev_priv);
+ ecobus = I915_READ(ECOBUS);
+ __gen6_gt_force_wake_mt_put(dev_priv);
+ mutex_unlock(&dev->struct_mutex);
+
+ if (ecobus & FORCEWAKE_MT_ENABLE) {
+ DRM_DEBUG_KMS("Using MT version of forcewake\n");
+ dev_priv->display.force_wake_get =
+ __gen6_gt_force_wake_mt_get;
+ dev_priv->display.force_wake_put =
+ __gen6_gt_force_wake_mt_put;
+ }
+ }
+
if (HAS_PCH_IBX(dev))
dev_priv->display.init_pch_clock_gating = ibx_init_clock_gating;
else if (HAS_PCH_CPT(dev))