From: Gabe Teeger <gabe.tee...@amd.com>

[Why]
We wait for mpc idle while in a locked state, leading to potential
deadlock.

[What]
Move the wait_for_idle call to outside of HW lock. This and a
call to wait_drr_doublebuffer_pending_clear are moved added to a new
static helper function called wait_for_outstanding_hw_updates, to make
the interface clearer.

Cc: sta...@vger.kernel.org
Fixes: 8f0d304d21b3 ("drm/amd/display: Do not commit pipe when updating DRR")
Reviewed-by: Jun Lei <jun....@amd.com>
Acked-by: Hamza Mahfooz <hamza.mahf...@amd.com>
Signed-off-by: Gabe Teeger <gabe.tee...@amd.com>
---
 drivers/gpu/drm/amd/display/dc/Makefile       |  1 +
 drivers/gpu/drm/amd/display/dc/core/dc.c      | 58 +++++++++++++------
 .../drm/amd/display/dc/dcn20/dcn20_hwseq.c    | 11 ----
 3 files changed, 42 insertions(+), 28 deletions(-)

diff --git a/drivers/gpu/drm/amd/display/dc/Makefile 
b/drivers/gpu/drm/amd/display/dc/Makefile
index 69ffd4424dc7..1b8c2aef4633 100644
--- a/drivers/gpu/drm/amd/display/dc/Makefile
+++ b/drivers/gpu/drm/amd/display/dc/Makefile
@@ -78,3 +78,4 @@ DC_EDID += dc_edid_parser.o
 AMD_DISPLAY_DMUB = $(addprefix $(AMDDALPATH)/dc/,$(DC_DMUB))
 AMD_DISPLAY_EDID = $(addprefix $(AMDDALPATH)/dc/,$(DC_EDID))
 AMD_DISPLAY_FILES += $(AMD_DISPLAY_DMUB) $(AMD_DISPLAY_EDID)
+
diff --git a/drivers/gpu/drm/amd/display/dc/core/dc.c 
b/drivers/gpu/drm/amd/display/dc/core/dc.c
index c6f6dc972c2a..5aab67868cb6 100644
--- a/drivers/gpu/drm/amd/display/dc/core/dc.c
+++ b/drivers/gpu/drm/amd/display/dc/core/dc.c
@@ -3501,6 +3501,45 @@ static void commit_planes_for_stream_fast(struct dc *dc,
                top_pipe_to_program->stream->update_flags.raw = 0;
 }
 
+static void wait_for_outstanding_hw_updates(struct dc *dc, const struct 
dc_state *dc_context)
+{
+/*
+ * This function calls HWSS to wait for any potentially double buffered
+ * operations to complete. It should be invoked as a pre-amble prior
+ * to full update programming before asserting any HW locks.
+ */
+       int pipe_idx;
+       int opp_inst;
+       int opp_count = dc->res_pool->pipe_count;
+       struct hubp *hubp;
+       int mpcc_inst;
+       const struct pipe_ctx *pipe_ctx;
+
+       for (pipe_idx = 0; pipe_idx < dc->res_pool->pipe_count; pipe_idx++) {
+               pipe_ctx = &dc_context->res_ctx.pipe_ctx[pipe_idx];
+
+               if (!pipe_ctx->stream)
+                       continue;
+
+               if 
(pipe_ctx->stream_res.tg->funcs->wait_drr_doublebuffer_pending_clear)
+                       
pipe_ctx->stream_res.tg->funcs->wait_drr_doublebuffer_pending_clear(pipe_ctx->stream_res.tg);
+
+               hubp = pipe_ctx->plane_res.hubp;
+               if (!hubp)
+                       continue;
+
+               mpcc_inst = hubp->inst;
+               // MPCC inst is equal to pipe index in practice
+               for (opp_inst = 0; opp_inst < opp_count; opp_inst++) {
+                       if 
(dc->res_pool->opps[opp_inst]->mpcc_disconnect_pending[mpcc_inst]) {
+                               
dc->res_pool->mpc->funcs->wait_for_idle(dc->res_pool->mpc, mpcc_inst);
+                               
dc->res_pool->opps[opp_inst]->mpcc_disconnect_pending[mpcc_inst] = false;
+                               break;
+                       }
+               }
+       }
+}
+
 static void commit_planes_for_stream(struct dc *dc,
                struct dc_surface_update *srf_updates,
                int surface_count,
@@ -3519,24 +3558,9 @@ static void commit_planes_for_stream(struct dc *dc,
        // dc->current_state anymore, so we have to cache it before we apply
        // the new SubVP context
        subvp_prev_use = false;
-
-
        dc_z10_restore(dc);
-
-       if (update_type == UPDATE_TYPE_FULL) {
-               /* wait for all double-buffer activity to clear on all pipes */
-               int pipe_idx;
-
-               for (pipe_idx = 0; pipe_idx < dc->res_pool->pipe_count; 
pipe_idx++) {
-                       struct pipe_ctx *pipe_ctx = 
&context->res_ctx.pipe_ctx[pipe_idx];
-
-                       if (!pipe_ctx->stream)
-                               continue;
-
-                       if 
(pipe_ctx->stream_res.tg->funcs->wait_drr_doublebuffer_pending_clear)
-                               
pipe_ctx->stream_res.tg->funcs->wait_drr_doublebuffer_pending_clear(pipe_ctx->stream_res.tg);
-               }
-       }
+       if (update_type == UPDATE_TYPE_FULL)
+               wait_for_outstanding_hw_updates(dc, context);
 
        if (update_type == UPDATE_TYPE_FULL) {
                dc_allow_idle_optimizations(dc, false);
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 dd4c7a7faf28..971fa8bf6d1f 100644
--- a/drivers/gpu/drm/amd/display/dc/dcn20/dcn20_hwseq.c
+++ b/drivers/gpu/drm/amd/display/dc/dcn20/dcn20_hwseq.c
@@ -1563,17 +1563,6 @@ static void dcn20_update_dchubp_dpp(
                        || plane_state->update_flags.bits.global_alpha_change
                        || 
plane_state->update_flags.bits.per_pixel_alpha_change) {
                // MPCC inst is equal to pipe index in practice
-               int mpcc_inst = hubp->inst;
-               int opp_inst;
-               int opp_count = dc->res_pool->pipe_count;
-
-               for (opp_inst = 0; opp_inst < opp_count; opp_inst++) {
-                       if 
(dc->res_pool->opps[opp_inst]->mpcc_disconnect_pending[mpcc_inst]) {
-                               
dc->res_pool->mpc->funcs->wait_for_idle(dc->res_pool->mpc, mpcc_inst);
-                               
dc->res_pool->opps[opp_inst]->mpcc_disconnect_pending[mpcc_inst] = false;
-                               break;
-                       }
-               }
                hws->funcs.update_mpcc(dc, pipe_ctx);
        }
 
-- 
2.41.0

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