[Intel-gfx] [PATCH] drm/i915: Add a parameter to disable SAGV

[Azhar Shaikh]

SAGV handling is currently broken which can result in system hangs.
Add a parameter to disable SAGV, till the SAGV handling is fixed.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=104975
Signed-off-by: Azhar Shaikh <azhar.shaikh at intel.com>
---
 drivers/gpu/drm/i915/i915_params.c | 3 +++
 drivers/gpu/drm/i915/i915_params.h | 3 ++-
 drivers/gpu/drm/i915/intel_pm.c    | 2 +-
 3 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_params.c b/drivers/gpu/drm/i915/i915_params.c
index 08108ce5be21..6aede52240b0 100644
--- a/drivers/gpu/drm/i915/i915_params.c
+++ b/drivers/gpu/drm/i915/i915_params.c
@@ -167,6 +167,9 @@ struct i915_params i915_modparams __read_mostly = {
 i915_param_named_unsafe(enable_dp_mst, bool, 0600,
 	"Enable multi-stream transport (MST) for new DisplayPort sinks. (default: true)");
 
+i915_param_named_unsafe(disable_sagv, bool, 0600,
+	"Disable SAGV (default: false)");
+
 #if IS_ENABLED(CONFIG_DRM_I915_DEBUG)
 i915_param_named_unsafe(inject_load_failure, uint, 0400,
 	"Force an error after a number of failure check points (0:disabled (default), N:force failure at the Nth failure check point)");
diff --git a/drivers/gpu/drm/i915/i915_params.h b/drivers/gpu/drm/i915/i915_params.h
index 430f5f9d0ff4..ff3c7d5dee2d 100644
--- a/drivers/gpu/drm/i915/i915_params.h
+++ b/drivers/gpu/drm/i915/i915_params.h
@@ -69,7 +69,8 @@
 	param(bool, nuclear_pageflip, false) \
 	param(bool, enable_dp_mst, true) \
 	param(bool, enable_dpcd_backlight, false) \
-	param(bool, enable_gvt, false)
+	param(bool, enable_gvt, false) \
+	param(bool, disable_sagv, false)
 
 #define MEMBER(T, member, ...) T member;
 struct i915_params {
diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index 21dac6ebc202..0b1a6cbf45aa 100644
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -3693,7 +3693,7 @@ bool intel_can_enable_sagv(struct drm_atomic_state *state)
 	int level, latency;
 	int sagv_block_time_us;
 
-	if (!intel_has_sagv(dev_priv))
+	if (!intel_has_sagv(dev_priv) || i915_modparams.disable_sagv)
 		return false;
 
 	if (IS_GEN9(dev_priv))
-- 
1.9.1