[PATCH 18/18] drm/amd/display: Disable DWB frame capture to emulate oneshot

[Alex Hung]

[WHY]
drm_writeback requires to capture exact one frame in each writeback
call.

[HOW]
frame_capture is disabled after each writeback is completed.

Signed-off-by: Alex Hung <alex.h...@amd.com>
---
 .../gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 14 +++++++++-
 .../gpu/drm/amd/display/dc/core/dc_stream.c   | 27 +++++++++++++++++++
 drivers/gpu/drm/amd/display/dc/dc_stream.h    |  4 +++
 3 files changed, 44 insertions(+), 1 deletion(-)

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 9051497eeed9..3e3efacec9e9 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
@@ -589,8 +589,20 @@ static void dm_crtc_high_irq(void *interrupt_params)
                                                       list_entry);
                        spin_unlock_irqrestore(&acrtc->wb_conn->job_lock, 
flags);
 
-                       if (job)
+                       if (job) {
+                               unsigned int v_total, refresh_hz;
+                               struct dc_stream_state *stream = 
acrtc->dm_irq_params.stream;
+
+                               v_total = stream->adjust.v_total_max ?
+                                         stream->adjust.v_total_max : 
stream->timing.v_total;
+                               refresh_hz = div_u64((uint64_t) 
stream->timing.pix_clk_100hz *
+                                            100LL, (v_total * 
stream->timing.h_total));
+                               mdelay(1000 / refresh_hz);
+
                                drm_writeback_signal_completion(acrtc->wb_conn, 
0);
+                               dc_stream_fc_disable_writeback(adev->dm.dc,
+                                                              
acrtc->dm_irq_params.stream, 0);
+                       }
                } else
                        DRM_ERROR("%s: no amdgpu_crtc wb_conn\n", __func__);
                acrtc->wb_pending = false;
diff --git a/drivers/gpu/drm/amd/display/dc/core/dc_stream.c 
b/drivers/gpu/drm/amd/display/dc/core/dc_stream.c
index 0e3ade920c4d..b65d9645f6ff 100644
--- a/drivers/gpu/drm/amd/display/dc/core/dc_stream.c
+++ b/drivers/gpu/drm/amd/display/dc/core/dc_stream.c
@@ -538,6 +538,33 @@ bool dc_stream_add_writeback(struct dc *dc,
        return true;
 }
 
+bool dc_stream_fc_disable_writeback(struct dc *dc,
+               struct dc_stream_state *stream,
+               uint32_t dwb_pipe_inst)
+{
+       struct dwbc *dwb = dc->res_pool->dwbc[dwb_pipe_inst];
+
+       if (stream == NULL) {
+               dm_error("DC: dc_stream is NULL!\n");
+               return false;
+       }
+
+       if (dwb_pipe_inst >= MAX_DWB_PIPES) {
+               dm_error("DC: writeback pipe is invalid!\n");
+               return false;
+       }
+
+       if (stream->num_wb_info > MAX_DWB_PIPES) {
+               dm_error("DC: num_wb_info is invalid!\n");
+               return false;
+       }
+
+       if (dwb->funcs->set_fc_enable)
+               dwb->funcs->set_fc_enable(dwb, DWB_FRAME_CAPTURE_DISABLE);
+
+       return true;
+}
+
 bool dc_stream_remove_writeback(struct dc *dc,
                struct dc_stream_state *stream,
                uint32_t dwb_pipe_inst)
diff --git a/drivers/gpu/drm/amd/display/dc/dc_stream.h 
b/drivers/gpu/drm/amd/display/dc/dc_stream.h
index 3697ea1d14c1..fac31a56b89d 100644
--- a/drivers/gpu/drm/amd/display/dc/dc_stream.h
+++ b/drivers/gpu/drm/amd/display/dc/dc_stream.h
@@ -455,6 +455,10 @@ bool dc_stream_add_writeback(struct dc *dc,
                struct dc_stream_state *stream,
                struct dc_writeback_info *wb_info);
 
+bool dc_stream_fc_disable_writeback(struct dc *dc,
+               struct dc_stream_state *stream,
+               uint32_t dwb_pipe_inst);
+
 bool dc_stream_remove_writeback(struct dc *dc,
                struct dc_stream_state *stream,
                uint32_t dwb_pipe_inst);
-- 
2.41.0