drm/msm/disp/dpu1: turn off vblank irqs aggressively in dpu driver

Set the flag vblank_disable_immediate = true to turn off vblank irqs
immediately as soon as drm_vblank_put is requested so that there are
no irqs triggered during idle state. This will reduce cpu wakeups
and help in power saving.

To enable vblank_disable_immediate flag the underlying KMS driver
needs to support high precision vblank timestamping and also a
reliable way of providing vblank counter which is incrementing
at the leading edge of vblank.

This patch also brings in changes to support vblank_disable_immediate
requirement in dpu driver.

Changes in v1:
 - Specify reason to add vblank timestamp support. (Rob).
 - Add changes to provide vblank counter from dpu driver.

Changes in v2:
 - Fix warn stack reported by Rob Clark with v2 patch.

Changes in v3:
 - Move back to HW frame counter (Rob).

Changes in v4:
 - Frame count mismatch was causing a DRM WARN stack spew.
   DPU HW will increment the frame count at the end of
   the sync, where as vblank will be triggered at the
   fetch_start counter which is calculated as v_total - vfp.
   This is to start fetching early for panels with low
   vbp w.r.t hw latency lines.

   Add logic to detect the line count if it falls between
   vactive and v_total then return incremented frame count value.

Signed-off-by: Kalyan Thota <kalyan_t@codeaurora.org>
Link: https://lore.kernel.org/r/1613651746-12783-1-git-send-email-kalyan_t@codeaurora.org
Signed-off-by: Rob Clark <robdclark@chromium.org>

1 files changed, 30 insertions, 0 deletions

diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
index 288e95ee8e1d..8d942052db8a 100644
--- a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
+++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
@@ -426,6 +426,36 @@ int dpu_encoder_helper_unregister_irq(struct dpu_encoder_phys *phys_enc,
 	return 0;
 }
 
+int dpu_encoder_get_frame_count(struct drm_encoder *drm_enc)
+{
+	struct dpu_encoder_virt *dpu_enc;
+	struct dpu_encoder_phys *phys;
+	int framecount = 0;
+
+	dpu_enc = to_dpu_encoder_virt(drm_enc);
+	phys = dpu_enc ? dpu_enc->cur_master : NULL;
+
+	if (phys && phys->ops.get_frame_count)
+		framecount = phys->ops.get_frame_count(phys);
+
+	return framecount;
+}
+
+int dpu_encoder_get_linecount(struct drm_encoder *drm_enc)
+{
+	struct dpu_encoder_virt *dpu_enc;
+	struct dpu_encoder_phys *phys;
+	int linecount = 0;
+
+	dpu_enc = to_dpu_encoder_virt(drm_enc);
+	phys = dpu_enc ? dpu_enc->cur_master : NULL;
+
+	if (phys && phys->ops.get_line_count)
+		linecount = phys->ops.get_line_count(phys);
+
+	return linecount;
+}
+
 void dpu_encoder_get_hw_resources(struct drm_encoder *drm_enc,
 				  struct dpu_encoder_hw_resources *hw_res)
 {