[Intel-gfx] [RFC 30/44] drm/i915: Added a module parameter for allowing scheduler overrides

[John.C.Harrison at Intel.com]

From: John Harrison <John.C.Harrison at Intel.com>

It can be useful to be able to disable certain features (e.g. the entire
scheduler) via a module parameter for debugging purposes. A parameter has the
advantage of not being a compile time switch but without implying that it can be
changed dynamically at runtime.
---
 drivers/gpu/drm/i915/i915_drv.h       |    1 +
 drivers/gpu/drm/i915/i915_params.c    |    4 ++++
 drivers/gpu/drm/i915/i915_scheduler.h |    5 +++++
 3 files changed, 10 insertions(+)

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index fbafa68..4d52c67 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -2053,6 +2053,7 @@ struct i915_params {
 	bool reset;
 	bool disable_display;
 	bool disable_vtd_wa;
+	int scheduler_override;
 };
 extern struct i915_params i915 __read_mostly;
 
diff --git a/drivers/gpu/drm/i915/i915_params.c b/drivers/gpu/drm/i915/i915_params.c
index d05a2af..ce99733 100644
--- a/drivers/gpu/drm/i915/i915_params.c
+++ b/drivers/gpu/drm/i915/i915_params.c
@@ -48,6 +48,7 @@ struct i915_params i915 __read_mostly = {
 	.disable_display = 0,
 	.enable_cmd_parser = 1,
 	.disable_vtd_wa = 0,
+	.scheduler_override = 0,
 };
 
 module_param_named(modeset, i915.modeset, int, 0400);
@@ -156,3 +157,6 @@ MODULE_PARM_DESC(disable_vtd_wa, "Disable all VT-d workarounds (default: false)"
 module_param_named(enable_cmd_parser, i915.enable_cmd_parser, int, 0600);
 MODULE_PARM_DESC(enable_cmd_parser,
 		 "Enable command parsing (1=enabled [default], 0=disabled)");
+
+module_param_named(scheduler_override, i915.scheduler_override, int, 0600);
+MODULE_PARM_DESC(scheduler_override, "Scheduler override option (default: 0)");
diff --git a/drivers/gpu/drm/i915/i915_scheduler.h b/drivers/gpu/drm/i915/i915_scheduler.h
index 1b3d51a..6dd4fea 100644
--- a/drivers/gpu/drm/i915/i915_scheduler.h
+++ b/drivers/gpu/drm/i915/i915_scheduler.h
@@ -84,6 +84,11 @@ struct i915_scheduler {
 	uint32_t    index;
 };
 
+/* Options for 'scheduler_override' module parameter: */
+enum {
+	i915_so_normal              = 0,
+};
+
 int         i915_scheduler_fly_seqno(struct intel_engine_cs *ring, uint32_t seqno);
 int         i915_scheduler_remove(struct intel_engine_cs *ring);
 int         i915_scheduler_flush(struct intel_engine_cs *ring, bool is_locked);
-- 
1.7.9.5