drm/amd/display: Add Underflow Asserts to dc

[Why]
For debugging underflow issues it can be useful to have asserts when the
underflow initially occurs.

[How]
Read the underflow status registers after actions that have a high risk
of causing underflow and assert that no underflow occurred. If underflow
occurred, clear the bit.

Signed-off-by: Thomas Lim <Thomas.Lim@amd.com>
Reviewed-by: Eric Yang <eric.yang2@amd.com>
Acked-by: Bhawanpreet Lakha <Bhawanpreet.Lakha@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

diff --git a/drivers/gpu/drm/amd/display/dc/dc.h b/drivers/gpu/drm/amd/display/dc/dc.h
index ffd1fe5df99ef1680b0315341172625eedbcd1ec..9aa01bf8c64dbb5224136bc17a476a9ea35c5000 100644 (file)
--- a/drivers/gpu/drm/amd/display/dc/dc.h
+++ b/drivers/gpu/drm/amd/display/dc/dc.h
@@ -329,6 +329,7 @@ struct dc_debug_options {
        int sr_exit_time_ns;
        int sr_enter_plus_exit_time_ns;
        int urgent_latency_ns;
+       uint32_t underflow_assert_delay_us;
        int percent_of_ideal_drambw;
        int dram_clock_change_latency_ns;
        bool optimized_watermark;

diff --git a/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_hw_sequencer.c b/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_hw_sequencer.c
index be245d4fe5c22692c9b09c65cfaae2de41ff67a1..f334756c1ce35abfa1a0e5741c777420b6da5f24 100644 (file)
--- a/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_hw_sequencer.c
+++ b/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_hw_sequencer.c
@@ -360,6 +360,23 @@ void dcn10_log_hw_state(struct dc *dc,
        DTN_INFO_END();
 }
 
+bool dcn10_did_underflow_occur(struct dc *dc, struct pipe_ctx *pipe_ctx)
+{
+       struct hubp *hubp = pipe_ctx->plane_res.hubp;
+       struct timing_generator *tg = pipe_ctx->stream_res.tg;
+
+       if (tg->funcs->is_optc_underflow_occurred(tg)) {
+               tg->funcs->clear_optc_underflow(tg);
+               return true;
+       }
+
+       if (hubp->funcs->hubp_get_underflow_status(hubp)) {
+               hubp->funcs->hubp_clear_underflow(hubp);
+               return true;
+       }
+       return false;
+}
+
 static void enable_power_gating_plane(
        struct dce_hwseq *hws,
        bool enable)
@@ -2332,6 +2349,7 @@ static void dcn10_apply_ctx_for_surface(
 {
        int i;
        struct timing_generator *tg;
+       uint32_t underflow_check_delay_us;
        bool removed_pipe[4] = { false };
        bool interdependent_update = false;
        struct pipe_ctx *top_pipe_to_program =
@@ -2346,11 +2364,22 @@ static void dcn10_apply_ctx_for_surface(
        interdependent_update = top_pipe_to_program->plane_state &&
                top_pipe_to_program->plane_state->update_flags.bits.full_update;
 
+       underflow_check_delay_us = dc->debug.underflow_assert_delay_us;
+
+       if (underflow_check_delay_us != 0xFFFFFFFF && dc->hwss.did_underflow_occur)
+               ASSERT(dc->hwss.did_underflow_occur(dc, top_pipe_to_program));
+
        if (interdependent_update)
                lock_all_pipes(dc, context, true);
        else
                dcn10_pipe_control_lock(dc, top_pipe_to_program, true);
 
+       if (underflow_check_delay_us != 0xFFFFFFFF)
+               udelay(underflow_check_delay_us);
+
+       if (underflow_check_delay_us != 0xFFFFFFFF && dc->hwss.did_underflow_occur)
+               ASSERT(dc->hwss.did_underflow_occur(dc, top_pipe_to_program));
+
        if (num_planes == 0) {
                /* OTG blank before remove all front end */
                dc->hwss.blank_pixel_data(dc, top_pipe_to_program, true);
@@ -3022,7 +3051,8 @@ static const struct hw_sequencer_funcs dcn10_funcs = {
        .disable_stream_gating = NULL,
        .enable_stream_gating = NULL,
        .setup_periodic_interrupt = dcn10_setup_periodic_interrupt,
-       .setup_vupdate_interrupt = dcn10_setup_vupdate_interrupt
+       .setup_vupdate_interrupt = dcn10_setup_vupdate_interrupt,
+       .did_underflow_occur = dcn10_did_underflow_occur
 };
 
 

diff --git a/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_hw_sequencer.h b/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_hw_sequencer.h
index ef94d6b15843fa9b228318091913df0e4a51740a..d3616b1948cc7be67e7ae0d5a39e4ae3a7a6ee71 100644 (file)
--- a/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_hw_sequencer.h
+++ b/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_hw_sequencer.h
@@ -71,6 +71,8 @@ void dcn10_get_hdr_visual_confirm_color(
                struct pipe_ctx *pipe_ctx,
                struct tg_color *color);
 
+bool dcn10_did_underflow_occur(struct dc *dc, struct pipe_ctx *pipe_ctx);
+
 void update_dchubp_dpp(
        struct dc *dc,
        struct pipe_ctx *pipe_ctx,

diff --git a/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_resource.c b/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_resource.c
index f6004bc53dce9c95a34edde27b6dd2ef9d08a937..29fd3cb9422bef147d52abf58da5ae865c2fc590 100644 (file)
--- a/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_resource.c
+++ b/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_resource.c
@@ -560,6 +560,7 @@ static const struct dc_debug_options debug_defaults_drv = {
                .az_endpoint_mute_only = true,
                .recovery_enabled = false, /*enable this by default after testing.*/
                .max_downscale_src_width = 3840,
+               .underflow_assert_delay_us = 0xFFFFFFFF,
 };
 
 static const struct dc_debug_options debug_defaults_diags = {
@@ -569,7 +570,8 @@ static const struct dc_debug_options debug_defaults_diags = {
                .clock_trace = true,
                .disable_stutter = true,
                .disable_pplib_clock_request = true,
-               .disable_pplib_wm_range = true
+               .disable_pplib_wm_range = true,
+               .underflow_assert_delay_us = 0xFFFFFFFF,
 };
 
 static void dcn10_dpp_destroy(struct dpp **dpp)

diff --git a/drivers/gpu/drm/amd/display/dc/inc/hw_sequencer.h b/drivers/gpu/drm/amd/display/dc/inc/hw_sequencer.h
index eb1c12ed026aeafcb45ad8d9c505a0e9a7da2c42..dab0168cd5cb51b608b65ba333022358bf8e0036 100644 (file)
--- a/drivers/gpu/drm/amd/display/dc/inc/hw_sequencer.h
+++ b/drivers/gpu/drm/amd/display/dc/inc/hw_sequencer.h
@@ -240,6 +240,7 @@ struct hw_sequencer_funcs {
 
        void (*setup_periodic_interrupt)(struct pipe_ctx *pipe_ctx, enum vline_select vline);
        void (*setup_vupdate_interrupt)(struct pipe_ctx *pipe_ctx);
+       bool (*did_underflow_occur)(struct dc *dc, struct pipe_ctx *pipe_ctx);
 
 };