drm/amd/display: delay fp2 programming until vactive before lock

[Why]
race condition of programming FP2 wrt pipe locking
and vactive state can cause underflow/black screen

[How]
Enforce the FP2 is only programmed during vactive,
and unlock pipe soon afterwards.

Signed-off-by: Martin Leung <martin.leung@amd.com>
Reviewed-by: Jun Lei <Jun.Lei@amd.com>
Acked-by: Qingqing Zhuo <qingqing.zhuo@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

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 9f7d6b0..cfc130e 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
@@ -2736,7 +2736,7 @@ static void dcn10_program_all_pipe_in_tree(
                                pipe_ctx->pipe_dlg_param.vupdate_width);
 
                pipe_ctx->stream_res.tg->funcs->set_vtg_params(
-                               pipe_ctx->stream_res.tg, &pipe_ctx->stream->timing);
+                               pipe_ctx->stream_res.tg, &pipe_ctx->stream->timing, true);
 
                if (hws->funcs.setup_vupdate_interrupt)
                        hws->funcs.setup_vupdate_interrupt(dc, pipe_ctx);

diff --git a/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_optc.c b/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_optc.c
index 48ccdcc..f033397 100644 (file)
--- a/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_optc.c
+++ b/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_optc.c
@@ -272,7 +272,7 @@ void optc1_program_timing(
                        vupdate_offset,
                        vupdate_width);
 
-       optc->funcs->set_vtg_params(optc, dc_crtc_timing);
+       optc->funcs->set_vtg_params(optc, dc_crtc_timing, true);
 
        /* TODO
         * patched_crtc_timing.flags.HORZ_COUNT_BY_TWO == 1
@@ -312,7 +312,7 @@ void optc1_program_timing(
 }
 
 void optc1_set_vtg_params(struct timing_generator *optc,
-               const struct dc_crtc_timing *dc_crtc_timing)
+               const struct dc_crtc_timing *dc_crtc_timing, bool program_fp2)
 {
        struct dc_crtc_timing patched_crtc_timing;
        uint32_t asic_blank_end;
@@ -348,9 +348,12 @@ void optc1_set_vtg_params(struct timing_generator *optc,
                }
        }
 
-       REG_UPDATE_2(CONTROL,
-                       VTG0_FP2, v_fp2,
-                       VTG0_VCOUNT_INIT, v_init);
+       if (program_fp2)
+               REG_UPDATE_2(CONTROL,
+                               VTG0_FP2, v_fp2,
+                               VTG0_VCOUNT_INIT, v_init);
+       else
+               REG_UPDATE(CONTROL, VTG0_VCOUNT_INIT, v_init);
 }
 
 void optc1_set_blank_data_double_buffer(struct timing_generator *optc, bool enable)

diff --git a/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_optc.h b/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_optc.h
index 344eb48..b12bd9a 100644 (file)
--- a/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_optc.h
+++ b/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_optc.h
@@ -700,6 +700,6 @@ bool optc1_get_crc(struct timing_generator *optc,
 bool optc1_is_two_pixels_per_containter(const struct dc_crtc_timing *timing);
 
 void optc1_set_vtg_params(struct timing_generator *optc,
-               const struct dc_crtc_timing *dc_crtc_timing);
+               const struct dc_crtc_timing *dc_crtc_timing, bool program_fp2);
 
 #endif /* __DC_TIMING_GENERATOR_DCN10_H__ */

diff --git a/drivers/gpu/drm/amd/display/dc/dcn20/dcn20_hwseq.c b/drivers/gpu/drm/amd/display/dc/dcn20/dcn20_hwseq.c
index abcb060..52bdbf2 100644 (file)
--- a/drivers/gpu/drm/amd/display/dc/dcn20/dcn20_hwseq.c
+++ b/drivers/gpu/drm/amd/display/dc/dcn20/dcn20_hwseq.c
@@ -1214,6 +1214,17 @@ void dcn20_pipe_control_lock(
                !flip_immediate)
            dcn20_setup_gsl_group_as_lock(dc, pipe, false);
 
+
+       // If changing VTG FP2: wait until back in vactive to program FP2
+       // Need to ensure that pipe unlock happens soon after to minimize race condition
+       if (!lock && pipe->update_flags.bits.global_sync) {
+               pipe->stream_res.tg->funcs->wait_for_state(pipe->stream_res.tg, CRTC_STATE_VBLANK);
+               pipe->stream_res.tg->funcs->wait_for_state(pipe->stream_res.tg, CRTC_STATE_VACTIVE);
+
+               pipe->stream_res.tg->funcs->set_vtg_params(
+                               pipe->stream_res.tg, &pipe->stream->timing, true);
+       }
+
        if (pipe->stream && should_use_dmub_lock(pipe->stream->link)) {
                union dmub_hw_lock_flags hw_locks = { 0 };
                struct dmub_hw_lock_inst_flags inst_flags = { 0 };
@@ -1595,7 +1606,7 @@ static void dcn20_program_pipe(
                                pipe_ctx->pipe_dlg_param.vupdate_width);
 
                pipe_ctx->stream_res.tg->funcs->set_vtg_params(
-                               pipe_ctx->stream_res.tg, &pipe_ctx->stream->timing);
+                               pipe_ctx->stream_res.tg, &pipe_ctx->stream->timing, false);
 
                if (hws->funcs.setup_vupdate_interrupt)
                        hws->funcs.setup_vupdate_interrupt(dc, pipe_ctx);
@@ -1695,14 +1706,6 @@ void dcn20_program_front_end_for_ctx(
                                && context->res_ctx.pipe_ctx[i].stream)
                        hws->funcs.blank_pixel_data(dc, &context->res_ctx.pipe_ctx[i], true);
 
-       /* wait for outstanding pending changes before adding or removing planes */
-       for (i = 0; i < dc->res_pool->pipe_count; i++) {
-               if (context->res_ctx.pipe_ctx[i].update_flags.bits.disable ||
-                               context->res_ctx.pipe_ctx[i].update_flags.bits.enable) {
-                       dc->hwss.wait_for_pending_cleared(dc, context);
-                       break;
-               }
-       }
 
        /* Disconnect mpcc */
        for (i = 0; i < dc->res_pool->pipe_count; i++)
@@ -1856,7 +1859,7 @@ bool dcn20_update_bandwidth(
                                        pipe_ctx->pipe_dlg_param.vupdate_width);
 
                        pipe_ctx->stream_res.tg->funcs->set_vtg_params(
-                                       pipe_ctx->stream_res.tg, &pipe_ctx->stream->timing);
+                                       pipe_ctx->stream_res.tg, &pipe_ctx->stream->timing, false);
 
                        if (pipe_ctx->prev_odm_pipe == NULL)
                                hws->funcs.blank_pixel_data(dc, pipe_ctx, blank);

diff --git a/drivers/gpu/drm/amd/display/dc/inc/hw/timing_generator.h b/drivers/gpu/drm/amd/display/dc/inc/hw/timing_generator.h
index 12d5718..f7632fe 100644 (file)
--- a/drivers/gpu/drm/amd/display/dc/inc/hw/timing_generator.h
+++ b/drivers/gpu/drm/amd/display/dc/inc/hw/timing_generator.h
@@ -271,7 +271,7 @@ struct timing_generator_funcs {
                        struct dc_crtc_timing *hw_crtc_timing);
 
        void (*set_vtg_params)(struct timing_generator *optc,
-                       const struct dc_crtc_timing *dc_crtc_timing);
+                       const struct dc_crtc_timing *dc_crtc_timing, bool program_fp2);
 
        void (*set_dsc_config)(struct timing_generator *optc,
                               enum optc_dsc_mode dsc_mode,