Empirical evidence suggests that we need to: On at least one ivb
machine when running the hangman i-g-t test, the rings don't properly
initialize properly - the RING_START registers seems to be stuck at
all zeros.
Holding forcewake around this register init sequences makes chip reset
reliable again. Note that this is not the first such issue:
commit f01db988ef6f6c70a6cc36ee71e4a98a68901229
Author: Sean Paul <seanpaul at chromium.org>
Date: Fri Mar 16 12:43:22 2012 -0400
drm/i915: Add wait_for in init_ring_common
added delay loops to make RING_START and RING_CTL initialization
reliable on the blt ring at boot-up. So I guess it won't hurt if we do
this unconditionally for all force_wake needing gpus.
To avoid copy&pasting of the HAS_FORCE_WAKE check I've added a new
intel_info bit for that.
Cc: stable at vger.kernel.org
Reported-by: Yang Guang <guang.a.yang at intel.com>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=50522
Signed-Off-by: Daniel Vetter <daniel.vetter at ffwll.ch>
---
drivers/gpu/drm/i915/i915_drv.c | 13 +++++++++----
drivers/gpu/drm/i915/i915_drv.h | 3 +++
drivers/gpu/drm/i915/intel_ringbuffer.c | 9 ++++++++-
3 files changed, 20 insertions(+), 5 deletions(-)
diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
index 238a521..a0c76aa 100644
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -233,6 +233,7 @@ static const struct intel_device_info intel_sandybridge_d_info = {
.has_blt_ring = 1,
.has_llc = 1,
.has_pch_split = 1,
+ .has_force_wake = 1
};
static const struct intel_device_info intel_sandybridge_m_info = {
@@ -243,6 +244,7 @@ static const struct intel_device_info intel_sandybridge_m_info = {
.has_blt_ring = 1,
.has_llc = 1,
.has_pch_split = 1,
+ .has_force_wake = 1
};
static const struct intel_device_info intel_ivybridge_d_info = {
@@ -252,6 +254,7 @@ static const struct intel_device_info intel_ivybridge_d_info = {
.has_blt_ring = 1,
.has_llc = 1,
.has_pch_split = 1,
+ .has_force_wake = 1
};
static const struct intel_device_info intel_ivybridge_m_info = {
@@ -262,6 +265,7 @@ static const struct intel_device_info intel_ivybridge_m_info = {
.has_blt_ring = 1,
.has_llc = 1,
.has_pch_split = 1,
+ .has_force_wake = 1
};
static const struct intel_device_info intel_valleyview_m_info = {
@@ -289,6 +293,7 @@ static const struct intel_device_info intel_haswell_d_info = {
.has_blt_ring = 1,
.has_llc = 1,
.has_pch_split = 1,
+ .has_force_wake = 1
};
static const struct intel_device_info intel_haswell_m_info = {
@@ -298,6 +303,7 @@ static const struct intel_device_info intel_haswell_m_info = {
.has_blt_ring = 1,
.has_llc = 1,
.has_pch_split = 1,
+ .has_force_wake = 1
};
static const struct pci_device_id pciidlist[] = { /* aka */
@@ -1139,10 +1145,9 @@ MODULE_LICENSE("GPL and additional rights");
/* We give fast paths for the really cool registers */
#define NEEDS_FORCE_WAKE(dev_priv, reg) \
- (((dev_priv)->info->gen >= 6) && \
- ((reg) < 0x40000) && \
- ((reg) != FORCEWAKE)) && \
- (!IS_VALLEYVIEW((dev_priv)->dev))
+ ((HAS_FORCE_WAKE((dev_priv)->dev)) && \
+ ((reg) < 0x40000) && \
+ ((reg) != FORCEWAKE))
#define __i915_read(x, y) \
u##x i915_read##x(struct drm_i915_private *dev_priv, u32 reg) { \
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index ccabadd..7cc36db 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -285,6 +285,7 @@ struct intel_device_info {
u8 is_ivybridge:1;
u8 is_valleyview:1;
u8 has_pch_split:1;
+ u8 has_force_wake:1;
u8 is_haswell:1;
u8 has_fbc:1;
u8 has_pipe_cxsr:1;
@@ -1105,6 +1106,8 @@ struct drm_i915_file_private {
#define HAS_PCH_CPT(dev) (INTEL_PCH_TYPE(dev) == PCH_CPT)
#define HAS_PCH_IBX(dev) (INTEL_PCH_TYPE(dev) == PCH_IBX)
+#define HAS_FORCE_WAKE(dev) (INTEL_INFO(dev)->has_force_wake)
+
#include "i915_trace.h"
/**
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
index 89a5e7f..bdb37f2 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.c
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
@@ -266,10 +266,14 @@ u32 intel_ring_get_active_head(struct intel_ring_buffer *ring)
static int init_ring_common(struct intel_ring_buffer *ring)
{
- drm_i915_private_t *dev_priv = ring->dev->dev_private;
+ struct drm_device *dev = ring->dev;
+ drm_i915_private_t *dev_priv = dev->dev_private;
struct drm_i915_gem_object *obj = ring->obj;
u32 head;
+ if (HAS_FORCE_WAKE(dev))
+ gen6_gt_force_wake_get(dev_priv);
+
/* Stop the ring if it's running. */
I915_WRITE_CTL(ring, 0);
I915_WRITE_HEAD(ring, 0);
@@ -328,6 +332,9 @@ static int init_ring_common(struct intel_ring_buffer *ring)
ring->space = ring_space(ring);
}
+ if (HAS_FORCE_WAKE(dev))
+ gen6_gt_force_wake_put(dev_priv);
+
return 0;
}
--
1.7.10
