The hardware already takes care of disabling and recompressing FBC
when we do a page flip, so all we need to do is to update the fence
registers and move on.
One of the important things to notice is that on the pre-gen6
platforms the fence is programmed on the FBC control register and the
documentation says we can't update the control register while FBC is
enabled. This would basically mean we'd have to to disable+enable FBC
at every flip in order to make sure the hardware tracking still works,
which doesn't seem to make too much sense. So I sent an email to the
hardware team requesting some clarification. The information I got was
this:
"I don't think any hardware is latching on to 0x100100, 0x100104, or
the old fence number in FBC_CTL. Instructions against changing on the
fly would be to simplify testing and ensure you don't miss any
invalidation that happened right at that time."
So I guess we're fine for flips. But I can't really say I tested FBC
on these ancient platforms - nor that I'll ever propose enabling FBC
by default on them exactly because of problems like these.
v2: Add comment at flush() (Chris).
Testcase: igt/kms_frontbuffer_tracking/fbc*-fliptrack
Signed-off-by: Paulo Zanoni <paulo.r.zanoni@xxxxxxxxx>
---
drivers/gpu/drm/i915/i915_drv.h | 1 +
drivers/gpu/drm/i915/i915_reg.h | 3 +
drivers/gpu/drm/i915/intel_display.c | 1 -
drivers/gpu/drm/i915/intel_drv.h | 2 +
drivers/gpu/drm/i915/intel_fbc.c | 103 ++++++++++++++++++++++++++++++-
drivers/gpu/drm/i915/intel_frontbuffer.c | 1 +
6 files changed, 108 insertions(+), 3 deletions(-)
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index ee14962..77da500 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -928,6 +928,7 @@ struct i915_fbc {
bool (*fbc_enabled)(struct drm_i915_private *dev_priv);
void (*enable_fbc)(struct intel_crtc *crtc);
void (*disable_fbc)(struct drm_i915_private *dev_priv);
+ void (*flip_prepare)(struct drm_i915_private *dev_priv);
};
/**
diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index 8942532..3d598a2 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -2028,6 +2028,7 @@ enum skl_disp_power_wells {
#define FBC_CTL_C3_IDLE (1<<13)
#define FBC_CTL_STRIDE_SHIFT (5)
#define FBC_CTL_FENCENO_SHIFT (0)
+#define FBC_CTL_FENCENO_MASK 0xF
#define FBC_COMMAND 0x0320c
#define FBC_CMD_COMPRESS (1<<0)
#define FBC_STATUS 0x03210
@@ -2064,6 +2065,7 @@ enum skl_disp_power_wells {
#define DPFC_CTL_LIMIT_1X (0<<6)
#define DPFC_CTL_LIMIT_2X (1<<6)
#define DPFC_CTL_LIMIT_4X (2<<6)
+#define DPFC_CTL_FENCE_MASK 0xF
#define DPFC_RECOMP_CTL 0x320c
#define DPFC_RECOMP_STALL_EN (1<<27)
#define DPFC_RECOMP_STALL_WM_SHIFT (16)
@@ -2086,6 +2088,7 @@ enum skl_disp_power_wells {
#define FBC_CTL_FALSE_COLOR (1<<10)
/* The bit 28-8 is reserved */
#define DPFC_RESERVED (0x1FFFFF00)
+#define ILK_DPFC_FENCE_MASK 0xF
#define ILK_DPFC_RECOMP_CTL 0x4320c
#define ILK_DPFC_STATUS 0x43210
#define ILK_DPFC_FENCE_YOFF 0x43218
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index bc1907e..d9378c3 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -11502,7 +11502,6 @@ static int intel_crtc_page_flip(struct drm_crtc *crtc,
to_intel_plane(primary)->frontbuffer_bit);
mutex_unlock(&dev->struct_mutex);
- intel_fbc_disable_crtc(intel_crtc);
intel_frontbuffer_flip_prepare(dev,
to_intel_plane(primary)->frontbuffer_bit);
diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index 08847d0..9065a8f 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -1305,6 +1305,8 @@ void intel_fbc_invalidate(struct drm_i915_private *dev_priv,
enum fb_op_origin origin);
void intel_fbc_flush(struct drm_i915_private *dev_priv,
unsigned int frontbuffer_bits, enum fb_op_origin origin);
+void intel_fbc_flip_prepare(struct drm_i915_private *dev_priv,
+ unsigned int frontbuffer_bits);
void intel_fbc_cleanup_cfb(struct drm_i915_private *dev_priv);
/* intel_hdmi.c */
diff --git a/drivers/gpu/drm/i915/intel_fbc.c b/drivers/gpu/drm/i915/intel_fbc.c
index d9d7e54..62f158b 100644
--- a/drivers/gpu/drm/i915/intel_fbc.c
+++ b/drivers/gpu/drm/i915/intel_fbc.c
@@ -82,6 +82,22 @@ static void i8xx_fbc_disable(struct drm_i915_private *dev_priv)
DRM_DEBUG_KMS("disabled FBC\n");
}
+static void i8xx_fbc_flip_prepare(struct drm_i915_private *dev_priv)
+{
+ struct intel_crtc *crtc = dev_priv->fbc.crtc;
+ struct drm_framebuffer *fb = crtc->base.primary->fb;
+ struct drm_i915_gem_object *obj = intel_fb_obj(fb);
+ uint32_t val;
+
+ /* Although the documentation suggests we can't change DPFC_CONTROL
+ * while compression is enabled, the hardware guys said that updating
+ * the fence register bits during a flip is fine. */
+ val = I915_READ(FBC_CONTROL);
+ val &= ~FBC_CTL_FENCENO_MASK;
+ val |= obj->fence_reg;
+ I915_WRITE(FBC_CONTROL, val);
+}
+
static void i8xx_fbc_enable(struct intel_crtc *crtc)
{
struct drm_i915_private *dev_priv = crtc->base.dev->dev_private;
@@ -161,6 +177,22 @@ static void g4x_fbc_enable(struct intel_crtc *crtc)
DRM_DEBUG_KMS("enabled fbc on plane %c\n", plane_name(crtc->plane));
}
+static void g4x_fbc_flip_prepare(struct drm_i915_private *dev_priv)
+{
+ struct intel_crtc *crtc = dev_priv->fbc.crtc;
+ struct drm_framebuffer *fb = crtc->base.primary->fb;
+ struct drm_i915_gem_object *obj = intel_fb_obj(fb);
+ uint32_t val;
+
+ /* Although the documentation suggests we can't change DPFC_CONTROL
+ * while compression is enabled, the hardware guys said that updating
+ * the fence register bits during a flip is fine. */
+ val = I915_READ(DPFC_CONTROL);
+ val &= ~DPFC_CTL_FENCE_MASK;
+ val |= obj->fence_reg;
+ I915_WRITE(DPFC_CONTROL, val);
+}
+
static void g4x_fbc_disable(struct drm_i915_private *dev_priv)
{
u32 dpfc_ctl;
@@ -236,6 +268,31 @@ static void ilk_fbc_enable(struct intel_crtc *crtc)
DRM_DEBUG_KMS("enabled fbc on plane %c\n", plane_name(crtc->plane));
}
+static void ilk_fbc_flip_prepare(struct drm_i915_private *dev_priv)
+{
+ struct intel_crtc *crtc = dev_priv->fbc.crtc;
+ struct drm_framebuffer *fb = crtc->base.primary->fb;
+ struct drm_i915_gem_object *obj = intel_fb_obj(fb);
+ uint32_t val;
+
+ /* Although the documentation suggests we can't change DPFC_CONTROL
+ * while compression is enabled, the hardware guys said that updating
+ * the fence register bits during a flip is fine. */
+ val = I915_READ(ILK_DPFC_CONTROL);
+ val &= ~ILK_DPFC_FENCE_MASK;
+ val |= obj->fence_reg;
+ I915_WRITE(ILK_DPFC_CONTROL, val);
+}
+
+static void snb_fbc_flip_prepare(struct drm_i915_private *dev_priv)
+{
+ struct intel_crtc *crtc = dev_priv->fbc.crtc;
+ struct drm_framebuffer *fb = crtc->base.primary->fb;
+ struct drm_i915_gem_object *obj = intel_fb_obj(fb);
+
+ I915_WRITE(SNB_DPFC_CTL_SA, SNB_CPU_FENCE_ENABLE | obj->fence_reg);
+}
+
static void ilk_fbc_disable(struct drm_i915_private *dev_priv)
{
u32 dpfc_ctl;
@@ -1021,13 +1078,48 @@ void intel_fbc_flush(struct drm_i915_private *dev_priv,
if (origin == ORIGIN_GTT)
return;
+ /* Hardware tracking already recompresses the CFB (nuke) for us if FBC
+ * is enabled and we do a page flip, so we can safely ignore it here.
+ * FBC may be disabled in case we got an invalidate() before the
+ * flush(), so we'll still have to check that case below. */
+ if (origin == ORIGIN_FLIP && dev_priv->fbc.enabled)
+ return;
+
mutex_lock(&dev_priv->fbc.lock);
dev_priv->fbc.busy_bits &= ~frontbuffer_bits;
if (!dev_priv->fbc.busy_bits) {
- __intel_fbc_disable(dev_priv);
- __intel_fbc_update(dev_priv);
+ if (origin == ORIGIN_FLIP) {
+ __intel_fbc_update(dev_priv);
+ } else {
+ __intel_fbc_disable(dev_priv);
+ __intel_fbc_update(dev_priv);
+ }
+ }
+
+ mutex_unlock(&dev_priv->fbc.lock);
+}
+
+void intel_fbc_flip_prepare(struct drm_i915_private *dev_priv,
+ unsigned int frontbuffer_bits)
+{
+ unsigned int fbc_bits;
+
+ if (!fbc_supported(dev_priv))
+ return;
+
+ mutex_lock(&dev_priv->fbc.lock);
+
+ if (dev_priv->fbc.enabled) {
+ fbc_bits = INTEL_FRONTBUFFER_PRIMARY(dev_priv->fbc.crtc->pipe);
+ if (fbc_bits & frontbuffer_bits)
+ dev_priv->fbc.flip_prepare(dev_priv);
+ } else if (dev_priv->fbc.fbc_work) {
+ fbc_bits = INTEL_FRONTBUFFER_PRIMARY(
+ dev_priv->fbc.fbc_work->crtc->pipe);
+ if (fbc_bits & frontbuffer_bits)
+ __intel_fbc_disable(dev_priv);
}
mutex_unlock(&dev_priv->fbc.lock);
@@ -1063,18 +1155,25 @@ void intel_fbc_init(struct drm_i915_private *dev_priv)
dev_priv->fbc.fbc_enabled = ilk_fbc_enabled;
dev_priv->fbc.enable_fbc = gen7_fbc_enable;
dev_priv->fbc.disable_fbc = ilk_fbc_disable;
+ dev_priv->fbc.flip_prepare = snb_fbc_flip_prepare;
} else if (INTEL_INFO(dev_priv)->gen >= 5) {
dev_priv->fbc.fbc_enabled = ilk_fbc_enabled;
dev_priv->fbc.enable_fbc = ilk_fbc_enable;
dev_priv->fbc.disable_fbc = ilk_fbc_disable;
+ if (INTEL_INFO(dev_priv)->gen == 5)
+ dev_priv->fbc.flip_prepare = ilk_fbc_flip_prepare;
+ else
+ dev_priv->fbc.flip_prepare = snb_fbc_flip_prepare;
} else if (IS_GM45(dev_priv)) {
dev_priv->fbc.fbc_enabled = g4x_fbc_enabled;
dev_priv->fbc.enable_fbc = g4x_fbc_enable;
dev_priv->fbc.disable_fbc = g4x_fbc_disable;
+ dev_priv->fbc.flip_prepare = g4x_fbc_flip_prepare;
} else {
dev_priv->fbc.fbc_enabled = i8xx_fbc_enabled;
dev_priv->fbc.enable_fbc = i8xx_fbc_enable;
dev_priv->fbc.disable_fbc = i8xx_fbc_disable;
+ dev_priv->fbc.flip_prepare = i8xx_fbc_flip_prepare;
/* This value was pulled out of someone's hat */
I915_WRITE(FBC_CONTROL, 500 << FBC_CTL_INTERVAL_SHIFT);
diff --git a/drivers/gpu/drm/i915/intel_frontbuffer.c b/drivers/gpu/drm/i915/intel_frontbuffer.c
index ac85357..31a1ad3 100644
--- a/drivers/gpu/drm/i915/intel_frontbuffer.c
+++ b/drivers/gpu/drm/i915/intel_frontbuffer.c
@@ -192,6 +192,7 @@ void intel_frontbuffer_flip_prepare(struct drm_device *dev,
mutex_unlock(&dev_priv->fb_tracking.lock);
intel_psr_single_frame_update(dev, frontbuffer_bits);
+ intel_fbc_flip_prepare(dev_priv, frontbuffer_bits);
}
/**
--
2.6.1
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