drm/amd/display: Fix FBC topology change

With FBC enabled there was a potential null-deref
on topology change due to hardcorded pipe index.

Signed-off-by: Roman Li <Roman.Li@amd.com>
Reviewed-by: Harry Wentland <Harry.Wentland@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

diff --git a/drivers/gpu/drm/amd/display/dc/dce110/dce110_hw_sequencer.c b/drivers/gpu/drm/amd/display/dc/dce110/dce110_hw_sequencer.c
index 2ecb3482452db85244dc6b80eba039d21708b563..1a289381c62c8bdb6c7ffb90ef07ab878539e2b5 100644 (file)
--- a/drivers/gpu/drm/amd/display/dc/dce110/dce110_hw_sequencer.c
+++ b/drivers/gpu/drm/amd/display/dc/dce110/dce110_hw_sequencer.c
@@ -1690,9 +1690,13 @@ static void apply_min_clocks(
  *  Check if FBC can be enabled
  */
 static bool should_enable_fbc(struct dc *dc,
-                             struct dc_state *context)
+                             struct dc_state *context,
+                             uint32_t *pipe_idx)
 {
-       struct pipe_ctx *pipe_ctx = &context->res_ctx.pipe_ctx[0];
+       uint32_t i;
+       struct pipe_ctx *pipe_ctx = NULL;
+       struct resource_context *res_ctx = &context->res_ctx;
+
 
        ASSERT(dc->fbc_compressor);
 
@@ -1704,6 +1708,14 @@ static bool should_enable_fbc(struct dc *dc,
        if (context->stream_count != 1)
                return false;
 
+       for (i = 0; i < dc->res_pool->pipe_count; i++) {
+               if (res_ctx->pipe_ctx[i].stream) {
+                       pipe_ctx = &res_ctx->pipe_ctx[i];
+                       *pipe_idx = i;
+                       break;
+               }
+       }
+
        /* Only supports eDP */
        if (pipe_ctx->stream->sink->link->connector_signal != SIGNAL_TYPE_EDP)
                return false;
@@ -1729,11 +1741,14 @@ static bool should_enable_fbc(struct dc *dc,
 static void enable_fbc(struct dc *dc,
                       struct dc_state *context)
 {
-       if (should_enable_fbc(dc, context)) {
+       uint32_t pipe_idx = 0;
+
+       if (should_enable_fbc(dc, context, &pipe_idx)) {
                /* Program GRPH COMPRESSED ADDRESS and PITCH */
                struct compr_addr_and_pitch_params params = {0, 0, 0};
                struct compressor *compr = dc->fbc_compressor;
-               struct pipe_ctx *pipe_ctx = &context->res_ctx.pipe_ctx[0];
+               struct pipe_ctx *pipe_ctx = &context->res_ctx.pipe_ctx[pipe_idx];
+
 
                params.source_view_width = pipe_ctx->stream->timing.h_addressable;
                params.source_view_height = pipe_ctx->stream->timing.v_addressable;