[PATCH 10/12] drm/amd/display: Toggle for Disable Force Pstate Allow on Disable

Roman.Li at amd.com Roman.Li at amd.com
Wed Jul 30 18:59:01 UTC 2025


From: Ryan Seto <ryanseto at amd.com>

[Why & How]
In theory, driver should be able to support disabling force pstate allow
after hardware release however this behavior is not tested yet.
Introducing a new toggle to disable the force on the fly.

Reviewed-by: Dillon Varone <dillon.varone at amd.com>
Signed-off-by: Ryan Seto <ryanseto at amd.com>
Signed-off-by: Roman Li <roman.li at amd.com>
---
 drivers/gpu/drm/amd/display/dc/dc.h           |  1 +
 .../amd/display/dc/hwss/dcn401/dcn401_hwseq.c | 36 +++++++++++--------
 .../dc/resource/dcn401/dcn401_resource.c      |  1 +
 3 files changed, 24 insertions(+), 14 deletions(-)

diff --git a/drivers/gpu/drm/amd/display/dc/dc.h b/drivers/gpu/drm/amd/display/dc/dc.h
index c013b28207a1..a83227f6bb14 100644
--- a/drivers/gpu/drm/amd/display/dc/dc.h
+++ b/drivers/gpu/drm/amd/display/dc/dc.h
@@ -1073,6 +1073,7 @@ struct dc_debug_options {
 	unsigned int force_mall_ss_num_ways;
 	bool alloc_extra_way_for_cursor;
 	uint32_t subvp_extra_lines;
+	bool disable_force_pstate_allow_on_hw_release;
 	bool force_usr_allow;
 	/* uses value at boot and disables switch */
 	bool disable_dtb_ref_clk_switch;
diff --git a/drivers/gpu/drm/amd/display/dc/hwss/dcn401/dcn401_hwseq.c b/drivers/gpu/drm/amd/display/dc/hwss/dcn401/dcn401_hwseq.c
index fb949aeb1244..d5b5e2ce6ff6 100644
--- a/drivers/gpu/drm/amd/display/dc/hwss/dcn401/dcn401_hwseq.c
+++ b/drivers/gpu/drm/amd/display/dc/hwss/dcn401/dcn401_hwseq.c
@@ -1621,20 +1621,28 @@ void dcn401_unblank_stream(struct pipe_ctx *pipe_ctx,
 
 void dcn401_hardware_release(struct dc *dc)
 {
-	dc_dmub_srv_fams2_update_config(dc, dc->current_state, false);
-
-	/* If pstate unsupported, or still supported
-	 * by firmware, force it supported by dcn
-	 */
-	if (dc->current_state) {
-		if ((!dc->clk_mgr->clks.p_state_change_support ||
-				dc->current_state->bw_ctx.bw.dcn.fams2_global_config.features.bits.enable) &&
-				dc->res_pool->hubbub->funcs->force_pstate_change_control)
-			dc->res_pool->hubbub->funcs->force_pstate_change_control(
-					dc->res_pool->hubbub, true, true);
-
-		dc->current_state->bw_ctx.bw.dcn.clk.p_state_change_support = true;
-		dc->clk_mgr->funcs->update_clocks(dc->clk_mgr, dc->current_state, true);
+	if (!dc->debug.disable_force_pstate_allow_on_hw_release) {
+		dc_dmub_srv_fams2_update_config(dc, dc->current_state, false);
+
+		/* If pstate unsupported, or still supported
+		* by firmware, force it supported by dcn
+		*/
+		if (dc->current_state) {
+			if ((!dc->clk_mgr->clks.p_state_change_support ||
+					dc->current_state->bw_ctx.bw.dcn.fams2_global_config.features.bits.enable) &&
+					dc->res_pool->hubbub->funcs->force_pstate_change_control)
+				dc->res_pool->hubbub->funcs->force_pstate_change_control(
+						dc->res_pool->hubbub, true, true);
+
+			dc->current_state->bw_ctx.bw.dcn.clk.p_state_change_support = true;
+			dc->clk_mgr->funcs->update_clocks(dc->clk_mgr, dc->current_state, true);
+		}
+	} else {
+		if (dc->current_state) {
+			dc->clk_mgr->clks.p_state_change_support = false;
+			dc->clk_mgr->funcs->update_clocks(dc->clk_mgr, dc->current_state, true);
+		}
+		dc_dmub_srv_fams2_update_config(dc, dc->current_state, false);
 	}
 }
 
diff --git a/drivers/gpu/drm/amd/display/dc/resource/dcn401/dcn401_resource.c b/drivers/gpu/drm/amd/display/dc/resource/dcn401/dcn401_resource.c
index b3988e38d0a6..068c123ea8a8 100644
--- a/drivers/gpu/drm/amd/display/dc/resource/dcn401/dcn401_resource.c
+++ b/drivers/gpu/drm/amd/display/dc/resource/dcn401/dcn401_resource.c
@@ -708,6 +708,7 @@ static const struct dc_debug_options debug_defaults_drv = {
 	},
 	.use_max_lb = true,
 	.force_disable_subvp = false,
+	.disable_force_pstate_allow_on_hw_release = false,
 	.exit_idle_opt_for_cursor_updates = true,
 	.using_dml2 = true,
 	.using_dml21 = true,
-- 
2.34.1



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