[PATCH 2/2] drm/amd/display: enable idle optimizations for linux (MALL stutter)

[Bhawanpreet Lakha]

[Why]
We can only use this feature when the display is idle. When active vblank
irq count is 0 we know all the displays are idle.

[How]
-Add a active vblank irq counter
-Update the counter when we enable/disable vblank irq
-if vblank irq count is 0 we can consider mall stutter

Change-Id: Ib1e14a84ee2e8c6e057072128693449665012584
Signed-off-by: Bhawanpreet Lakha <Bhawanpreet.Lakha at amd.com>
Acked-by: Alex Deucher <alexander.deucher at amd.com>
Reviewed-by: Nick Kazlauskas <Nicholas.Kazlauskas at amd.com>
---
 drivers/gpu/drm/amd/display/Kconfig           |  6 +++++
 .../gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 22 +++++++++++++++++++
 .../gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h |  9 ++++++++
 drivers/gpu/drm/amd/display/dc/dc.h           |  3 +++
 4 files changed, 40 insertions(+)

diff --git a/drivers/gpu/drm/amd/display/Kconfig b/drivers/gpu/drm/amd/display/Kconfig
index 797b5d4b43e5..2444e664c7ee 100644
--- a/drivers/gpu/drm/amd/display/Kconfig
+++ b/drivers/gpu/drm/amd/display/Kconfig
@@ -23,6 +23,12 @@ config DRM_AMD_DC_HDCP
 	help
 	  Choose this option if you want to support HDCP authentication.
 
+config DRM_AMD_DC_MALL
+	bool "Enable MALL support"
+	depends on DRM_AMD_DC
+	help
+	  Choose this option if you want to support MALL
+
 config DRM_AMD_DC_SI
 	bool "AMD DC support for Southern Islands ASICs"
 	default n
diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
index a78ec16418b3..080f2a52cfed 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
@@ -5479,6 +5479,7 @@ static inline int dm_set_vblank(struct drm_crtc *crtc, bool enable)
 	struct amdgpu_crtc *acrtc = to_amdgpu_crtc(crtc);
 	struct amdgpu_device *adev = drm_to_adev(crtc->dev);
 	struct dm_crtc_state *acrtc_state = to_dm_crtc_state(crtc->state);
+	struct amdgpu_display_manager *dm = &adev->dm;
 	int rc = 0;
 
 	if (enable) {
@@ -5494,7 +5495,28 @@ static inline int dm_set_vblank(struct drm_crtc *crtc, bool enable)
 		return rc;
 
 	irq_source = IRQ_TYPE_VBLANK + acrtc->otg_inst;
+#if defined(CONFIG_DRM_AMD_DC_MALL)
+
+	if (!dc_interrupt_set(adev->dm.dc, irq_source, enable))
+		return -EBUSY;
+
+	mutex_lock(&dm->dc_lock);
+
+	if (enable)
+		dm->active_vblank_irq_count++;
+	else
+		dm->active_vblank_irq_count--;
+
+	dc_allow_idle_optimizations(
+		adev->dm.dc, dm->active_vblank_irq_count == 0 ? true : false);
+
+	DRM_DEBUG_DRIVER("Allow idle optimizations (MALL): %d\n", dm->active_vblank_irq_count == 0);
+	mutex_unlock(&dm->dc_lock);
+
+	return 0;
+#else
 	return dc_interrupt_set(adev->dm.dc, irq_source, enable) ? 0 : -EBUSY;
+#endif
 }
 
 static int dm_enable_vblank(struct drm_crtc *crtc)
diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h
index 251af783f6b1..cab44bbd2e35 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h
@@ -336,6 +336,15 @@ struct amdgpu_display_manager {
 	 */
 	const struct gpu_info_soc_bounding_box_v1_0 *soc_bounding_box;
 
+#if defined(CONFIG_DRM_AMD_DC_MALL)
+	/**
+	 * @active_vblank_irq_count
+	 *
+	 * number of currently active vblank irqs
+	 */
+	uint32_t active_vblank_irq_count;
+#endif
+
 #ifdef CONFIG_DEBUG_FS
 	/* set the crc calculation window*/
 	struct drm_property *crc_win_x_start_property;
diff --git a/drivers/gpu/drm/amd/display/dc/dc.h b/drivers/gpu/drm/amd/display/dc/dc.h
index 33642566bcb2..9d245033eb3d 100644
--- a/drivers/gpu/drm/amd/display/dc/dc.h
+++ b/drivers/gpu/drm/amd/display/dc/dc.h
@@ -504,6 +504,9 @@ struct dc_debug_options {
 	bool dmcub_emulation;
 #if defined(CONFIG_DRM_AMD_DC_DCN)
 	bool disable_idle_power_optimizations;
+#endif
+#ifdef CONFIG_DRM_AMD_DC_MALL
+	unsigned int mall_size_override;
 #endif
 	bool dmub_command_table; /* for testing only */
 	struct dc_bw_validation_profile bw_val_profile;
-- 
2.25.1