drm/i915: hold forcewake around ring hw init

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 f01db988ef
Author: Sean Paul <seanpaul@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.

v2: Fixup missing commas in static struct and properly handling the
error case in init_ring_common, both noticed by Jani Nikula.

Cc: stable@vger.kernel.org
Reported-and-tested-by: Yang Guang <guang.a.yang@intel.com>
Reviewed-by: Eugeni Dodonov <eugeni.dodonov@intel.com>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=50522
Signed-Off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
This commit is contained in:
Daniel Vetter 2012-06-04 11:18:15 +02:00
parent 3eef8918ff
commit b7884eb45e
3 changed files with 25 additions and 7 deletions

View File

@ -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) { \

View File

@ -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;
@ -1098,6 +1099,8 @@ 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"
/**

View File

@ -266,10 +266,15 @@ 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;
int ret = 0;
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);
@ -317,7 +322,8 @@ static int init_ring_common(struct intel_ring_buffer *ring)
I915_READ_HEAD(ring),
I915_READ_TAIL(ring),
I915_READ_START(ring));
return -EIO;
ret = -EIO;
goto out;
}
if (!drm_core_check_feature(ring->dev, DRIVER_MODESET))
@ -329,7 +335,11 @@ static int init_ring_common(struct intel_ring_buffer *ring)
ring->last_retired_head = -1;
}
return 0;
out:
if (HAS_FORCE_WAKE(dev))
gen6_gt_force_wake_put(dev_priv);
return ret;
}
static int