[PATCH 49/62] drm/i915/bdw: Use The GT mailbox for IPS enable/disable

Ben Widawsky
2013-11-03T04:08:26Z

v2: Squash in fixup from Ben to synchronize the GT mailbox commands.

CC: Art Runyan <arthur.j.runyan@intel.com>
Reviewed-by: Art Runyan <arthur.j.runyan@intel.com>
Signed-off-by: Ben Widawsky <ben@bwidawsk.net>
---
drivers/gpu/drm/i915/i915_drv.h | 2 +-
drivers/gpu/drm/i915/i915_reg.h | 1 +
drivers/gpu/drm/i915/intel_display.c | 36 ++++++++++++++++++++++++++----------
3 files changed, 28 insertions(+), 11 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 1a2e967..f222eb4 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -1803,7 +1803,7 @@ struct drm_i915_file_private {
#define HAS_PIPE_CXSR(dev) (INTEL_INFO(dev)->has_pipe_cxsr)
#define I915_HAS_FBC(dev) (INTEL_INFO(dev)->has_fbc)

-#define HAS_IPS(dev) (IS_ULT(dev))
+#define HAS_IPS(dev) (IS_ULT(dev) || IS_BROADWELL(dev))

#define HAS_DDI(dev) (INTEL_INFO(dev)->has_ddi)
#define HAS_POWER_WELL(dev) (IS_HASWELL(dev) || IS_GEN8(dev))
diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index 2a65f92..65f9631 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -4932,6 +4932,7 @@
#define GEN6_PCODE_WRITE_D_COMP 0x11
#define GEN6_ENCODE_RC6_VID(mv) (((mv) - 245) / 5)
#define GEN6_DECODE_RC6_VID(vids) (((vids) * 5) + 245)
+#define DISPLAY_IPS_CONTROL 0x19
#define GEN6_PCODE_DATA 0x138128
#define GEN6_PCODE_FREQ_IA_RATIO_SHIFT 8
#define GEN6_PCODE_FREQ_RING_RATIO_SHIFT 16
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index fce3b0d..fc4b4cf 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -3347,15 +3347,26 @@ void hsw_enable_ips(struct intel_crtc *crtc)
* only after intel_enable_plane. And intel_enable_plane already waits
* for a vblank, so all we need to do here is to enable the IPS bit. */
assert_plane_enabled(dev_priv, crtc->plane);
- I915_WRITE(IPS_CTL, IPS_ENABLE);
-
- /* The bit only becomes 1 in the next vblank, so this wait here is
- * essentially intel_wait_for_vblank. If we don't have this and don't
- * wait for vblanks until the end of crtc_enable, then the HW state
- * readout code will complain that the expected IPS_CTL value is not the
- * one we read. */
- if (wait_for(I915_READ_NOTRACE(IPS_CTL) & IPS_ENABLE, 50))
- DRM_ERROR("Timed out waiting for IPS enable\n");
+ if (IS_BROADWELL(crtc->base.dev)) {
+ mutex_lock(&dev_priv->rps.hw_lock);
+ WARN_ON(sandybridge_pcode_write(dev_priv, DISPLAY_IPS_CONTROL, 0xc0000000));
+ mutex_unlock(&dev_priv->rps.hw_lock);
+ /* Quoting Art Runyan: "its not safe to expect any particular
+ * value in IPS_CTL bit 31 after enabling IPS through the
+ * mailbox." Therefore we need to defer waiting on the state
+ * change.
+ * TODO: need to fix this for state checker
+ */
+ } else {
+ I915_WRITE(IPS_CTL, IPS_ENABLE);
+ /* The bit only becomes 1 in the next vblank, so this wait here
+ * is essentially intel_wait_for_vblank. If we don't have this
+ * and don't wait for vblanks until the end of crtc_enable, then
+ * the HW state readout code will complain that the expected
+ * IPS_CTL value is not the one we read. */
+ if (wait_for(I915_READ_NOTRACE(IPS_CTL) & IPS_ENABLE, 50))
+ DRM_ERROR("Timed out waiting for IPS enable\n");
+ }
}

void hsw_disable_ips(struct intel_crtc *crtc)
@@ -3367,7 +3378,12 @@ void hsw_disable_ips(struct intel_crtc *crtc)
return;

assert_plane_enabled(dev_priv, crtc->plane);
- I915_WRITE(IPS_CTL, 0);
+ if (IS_BROADWELL(crtc->base.dev)) {
+ mutex_lock(&dev_priv->rps.hw_lock);
+ WARN_ON(sandybridge_pcode_write(dev_priv, DISPLAY_IPS_CONTROL, 0));
+ mutex_unlock(&dev_priv->rps.hw_lock);
+ } else
+ I915_WRITE(IPS_CTL, 0);
POSTING_READ(IPS_CTL);

/* We need to wait for a vblank before we can disable the plane. */
--
1.8.4.2