Commit f1f0379e authored by Jessica Zhang's avatar Jessica Zhang Committed by Dmitry Baryshkov
Browse files

drm/msm/dpu: Fail atomic_check if multiple outputs request CDM block 



Currently, our hardware only supports a single output using CDM block at
most. Because of this, we cannot support cases where both writeback and DP
output request CDM simultaneously

To avoid this happening when CWB is enabled, change
msm_display_topoloy.needs_cdm into a num_cdm counter to track how many
outputs are requesting CDM block. Return EINVAL if multiple outputs are
trying to reserve CDM.

Signed-off-by: default avatarJessica Zhang <quic_jesszhan@quicinc.com>
Reviewed-by: default avatarDmitry Baryshkov <dmitry.baryshkov@linaro.org>
Patchwork: https://patchwork.freedesktop.org/patch/637499/
Link: https://lore.kernel.org/r/20250214-concurrent-wb-v6-6-a44c293cf422@quicinc.com


Signed-off-by: default avatarDmitry Baryshkov <dmitry.baryshkov@linaro.org>
parent 20972609

drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c

+2 −2
Original line number Diff line number Diff line
@@ -700,10 +700,10 @@ void dpu_encoder_update_topology(struct drm_encoder *drm_enc, 
		fb = conn_state->writeback_job->fb;



		if (fb && MSM_FORMAT_IS_YUV(msm_framebuffer_format(fb)))

			topology->needs_cdm = true;

			topology->num_cdm++;

	} else if (disp_info->intf_type == INTF_DP) {

		if (msm_dp_is_yuv_420_enabled(priv->dp[disp_info->h_tile_instance[0]], adj_mode))

			topology->needs_cdm = true;

			topology->num_cdm++;

	}

}

drivers/gpu/drm/msm/disp/dpu1/dpu_rm.c

+9 −3
Original line number Diff line number Diff line
@@ -585,7 +585,8 @@ static int _dpu_rm_reserve_dsc(struct dpu_rm *rm, 


static int _dpu_rm_reserve_cdm(struct dpu_rm *rm,

			       struct dpu_global_state *global_state,

			       uint32_t crtc_id)

			       uint32_t crtc_id,

			       int num_cdm)

{

	/* try allocating only one CDM block */

	if (!rm->cdm_blk) {
@@ -593,6 +594,11 @@ static int _dpu_rm_reserve_cdm(struct dpu_rm *rm, 
		return -EIO;

	}



	if (num_cdm > 1) {

		DPU_ERROR("More than 1 INTF requesting CDM\n");

		return -EINVAL;

	}



	if (global_state->cdm_to_crtc_id) {

		DPU_ERROR("CDM_0 is already allocated\n");

		return -EIO;
@@ -629,8 +635,8 @@ static int _dpu_rm_make_reservation( 
	if (ret)

		return ret;



	if (topology->needs_cdm) {

		ret = _dpu_rm_reserve_cdm(rm, global_state, crtc_id);

	if (topology->num_cdm > 0) {

		ret = _dpu_rm_reserve_cdm(rm, global_state, crtc_id, topology->num_cdm);

		if (ret) {

			DPU_ERROR("unable to find CDM blk\n");

			return ret;

drivers/gpu/drm/msm/disp/dpu1/dpu_rm.h

+3 −2
Original line number Diff line number Diff line
@@ -51,7 +51,8 @@ struct dpu_rm_sspp_requirements { 
 * @num_intf:     number of interfaces the panel is mounted on

 * @num_dspp:     number of dspp blocks used

 * @num_dsc:      number of Display Stream Compression (DSC) blocks used

 * @needs_cdm:    indicates whether cdm block is needed for this display topology

 * @num_cdm:      indicates how many outputs are requesting cdm block for

 *                    this display topology

 * @cwb_enabled:  indicates whether CWB is enabled for this display topology

 */

struct msm_display_topology {
@@ -59,7 +60,7 @@ struct msm_display_topology { 
	u32 num_intf;

	u32 num_dspp;

	u32 num_dsc;

	bool needs_cdm;

	int num_cdm;

	bool cwb_enabled;

};