[PATCH v2 14/16] drm/msm/dpu: reserve cdm blocks for writeback in case of YUV output

[Abhinav Kumar]

Reserve CDM blocks for writeback if the format of the output fb
is YUV. At the moment, the reservation is done only for writeback
but can easily be extended by relaxing the checks once other
interfaces are ready to output YUV.

changes in v2:
	- use needs_cdm from topology struct
	- drop fb related checks from atomic_mode_set()

Signed-off-by: Abhinav Kumar <quic_abhinavk at quicinc.com>
---
 drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c | 27 +++++++++++++++++++++
 1 file changed, 27 insertions(+)

diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
index 862912727925..a576e3e62429 100644
--- a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
+++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
@@ -16,6 +16,7 @@
 #include <drm/drm_crtc.h>
 #include <drm/drm_file.h>
 #include <drm/drm_probe_helper.h>
+#include <drm/drm_framebuffer.h>
 
 #include "msm_drv.h"
 #include "dpu_kms.h"
@@ -583,6 +584,7 @@ static int dpu_encoder_virt_atomic_check(
 	struct drm_display_mode *adj_mode;
 	struct msm_display_topology topology;
 	struct dpu_global_state *global_state;
+	struct drm_framebuffer *fb;
 	struct drm_dsc_config *dsc;
 	int i = 0;
 	int ret = 0;
@@ -623,6 +625,22 @@ static int dpu_encoder_virt_atomic_check(
 
 	topology = dpu_encoder_get_topology(dpu_enc, dpu_kms, adj_mode, crtc_state, dsc);
 
+	/*
+	 * Use CDM only for writeback at the moment as other interfaces cannot handle it.
+	 * if writeback itself cannot handle cdm for some reason it will fail in its atomic_check()
+	 * earlier.
+	 */
+	if (dpu_enc->disp_info.intf_type == INTF_WB && conn_state->writeback_job) {
+		fb = conn_state->writeback_job->fb;
+
+		if (fb && DPU_FORMAT_IS_YUV(to_dpu_format(msm_framebuffer_format(fb))))
+			topology.needs_cdm = true;
+		if (topology.needs_cdm && !dpu_enc->cur_master->hw_cdm)
+			crtc_state->mode_changed = true;
+		else if (!topology.needs_cdm && dpu_enc->cur_master->hw_cdm)
+			crtc_state->mode_changed = true;
+	}
+
 	/*
 	 * Release and Allocate resources on every modeset
 	 * Dont allocate when active is false.
@@ -1063,6 +1081,15 @@ static void dpu_encoder_virt_atomic_mode_set(struct drm_encoder *drm_enc,
 
 	dpu_enc->dsc_mask = dsc_mask;
 
+	if (dpu_enc->disp_info.intf_type == INTF_WB && conn_state->writeback_job) {
+		struct dpu_hw_blk *hw_cdm = NULL;
+
+		dpu_rm_get_assigned_resources(&dpu_kms->rm, global_state,
+					      drm_enc->base.id, DPU_HW_BLK_CDM,
+					      &hw_cdm, 1);
+		dpu_enc->cur_master->hw_cdm = hw_cdm ? to_dpu_hw_cdm(hw_cdm) : NULL;
+	}
+
 	cstate = to_dpu_crtc_state(crtc_state);
 
 	for (i = 0; i < num_lm; i++) {
-- 
2.40.1