[PATCH 5/6] drm/i915/display: add module parameter to enable DMC wakelock

[Luca Coelho]

This feature should be disabled by default until properly tested and
mature.  Add a module parameter to enable the feature for testing,
while keeping it disabled by default for now.

Additionally, only allow enabling via module parameter if the display
version is greater than 20.

Signed-off-by: Luca Coelho <luciano.coelho at intel.com>
---
 .../gpu/drm/i915/display/intel_display_params.c  |  5 +++++
 .../gpu/drm/i915/display/intel_display_params.h  |  1 +
 drivers/gpu/drm/i915/display/intel_dmc_wl.c      | 16 ++++++++++++++--
 3 files changed, 20 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/i915/display/intel_display_params.c b/drivers/gpu/drm/i915/display/intel_display_params.c
index 11e03cfb774d..f40b223cc8a1 100644
--- a/drivers/gpu/drm/i915/display/intel_display_params.c
+++ b/drivers/gpu/drm/i915/display/intel_display_params.c
@@ -116,6 +116,11 @@ intel_display_param_named_unsafe(enable_psr2_sel_fetch, bool, 0400,
 	"(0=disabled, 1=enabled) "
 	"Default: 1");
 
+intel_display_param_named_unsafe(enable_dmc_wl, bool, 0400,
+	"Enable DMC wakelock "
+	"(0=disabled, 1=enabled) "
+	"Default: 0");
+
 __maybe_unused
 static void _param_print_bool(struct drm_printer *p, const char *driver_name,
 			      const char *name, bool val)
diff --git a/drivers/gpu/drm/i915/display/intel_display_params.h b/drivers/gpu/drm/i915/display/intel_display_params.h
index 6206cc51df04..bf8dbbdb20a1 100644
--- a/drivers/gpu/drm/i915/display/intel_display_params.h
+++ b/drivers/gpu/drm/i915/display/intel_display_params.h
@@ -46,6 +46,7 @@ struct drm_i915_private;
 	param(int, enable_psr, -1, 0600) \
 	param(bool, psr_safest_params, false, 0400) \
 	param(bool, enable_psr2_sel_fetch, true, 0400) \
+	param(bool, enable_dmc_wl, false, 0400) \
 
 #define MEMBER(T, member, ...) T member;
 struct intel_display_params {
diff --git a/drivers/gpu/drm/i915/display/intel_dmc_wl.c b/drivers/gpu/drm/i915/display/intel_dmc_wl.c
index abe1ea92cf65..21ab67805ff1 100644
--- a/drivers/gpu/drm/i915/display/intel_dmc_wl.c
+++ b/drivers/gpu/drm/i915/display/intel_dmc_wl.c
@@ -79,6 +79,10 @@ void intel_dmc_wl_enable(struct drm_i915_private *i915)
 	struct intel_dmc_wl *wl = &i915->display.wl;
 	unsigned long flags;
 
+	if (!i915->display.params.enable_dmc_wl ||
+	    DISPLAY_VER(i915) <= 20)
+		return;
+
 	spin_lock_irqsave(&wl->lock, flags);
 
 	if (wl->enabled)
@@ -105,6 +109,10 @@ void intel_dmc_wl_disable(struct drm_i915_private *i915)
 	struct intel_dmc_wl *wl = &i915->display.wl;
 	unsigned long flags;
 
+	if (!i915->display.params.enable_dmc_wl ||
+	    DISPLAY_VER(i915) <= 20)
+		return;
+
 	spin_lock_irqsave(&wl->lock, flags);
 
 	/* FIXME: should we cancel the work? */
@@ -135,7 +143,9 @@ void intel_dmc_wl_get(struct drm_i915_private *i915, i915_reg_t reg)
 	unsigned long flags;
 	u32 ctl_value;
 
-	if (!intel_dmc_wl_check_range(reg.reg))
+	if (!i915->display.params.enable_dmc_wl ||
+	    DISPLAY_VER(i915) <= 20 ||
+	    !intel_dmc_wl_check_range(reg.reg))
 		return;
 
 	spin_lock_irqsave(&wl->lock, flags);
@@ -166,7 +176,9 @@ void intel_dmc_wl_put(struct drm_i915_private *i915, i915_reg_t reg)
 	struct intel_dmc_wl *wl = &i915->display.wl;
 	unsigned long flags;
 
-	if (!intel_dmc_wl_check_range(reg.reg))
+	if (!i915->display.params.enable_dmc_wl ||
+	    DISPLAY_VER(i915) <= 20 ||
+	    !intel_dmc_wl_check_range(reg.reg))
 		return;
 
 	spin_lock_irqsave(&wl->lock, flags);
-- 
2.39.2