From: Alvin Lee alvin.lee2@amd.com
[ Upstream commit 9a902a9073c287353e25913c0761bfed49d75a88 ]
[Description] - When we're in a no plane config, DCN is always asserting P-State allow - This creates a scenario where the P-State blackout can start just as VUPDATE takes place and transitions the DCN config to a one where one or more HUBP's are active which can result in underflow - To fix this issue, force p-state disallow and unforce after the transition from no planes case -> one or more planes active
Reviewed-by: Samson Tam samson.tam@amd.com Acked-by: Aurabindo Pillai aurabindo.pillai@amd.com Signed-off-by: Alvin Lee alvin.lee2@amd.com Signed-off-by: Alex Deucher alexander.deucher@amd.com Signed-off-by: Sasha Levin sashal@kernel.org --- .../amd/display/dc/hwss/dcn20/dcn20_hwseq.c | 20 +++++++++++++++++++ 1 file changed, 20 insertions(+)
diff --git a/drivers/gpu/drm/amd/display/dc/hwss/dcn20/dcn20_hwseq.c b/drivers/gpu/drm/amd/display/dc/hwss/dcn20/dcn20_hwseq.c index 608221b0dd5d..c3c83178eb1e 100644 --- a/drivers/gpu/drm/amd/display/dc/hwss/dcn20/dcn20_hwseq.c +++ b/drivers/gpu/drm/amd/display/dc/hwss/dcn20/dcn20_hwseq.c @@ -1877,6 +1877,8 @@ void dcn20_program_front_end_for_ctx( int i; struct dce_hwseq *hws = dc->hwseq; DC_LOGGER_INIT(dc->ctx->logger); + unsigned int prev_hubp_count = 0; + unsigned int hubp_count = 0;
if (resource_is_pipe_topology_changed(dc->current_state, context)) resource_log_pipe_topology_update(dc, context); @@ -1894,6 +1896,20 @@ void dcn20_program_front_end_for_ctx( } }
+ for (i = 0; i < dc->res_pool->pipe_count; i++) { + if (dc->current_state->res_ctx.pipe_ctx[i].plane_state) + prev_hubp_count++; + if (context->res_ctx.pipe_ctx[i].plane_state) + hubp_count++; + } + + if (prev_hubp_count == 0 && hubp_count > 0) { + if (dc->res_pool->hubbub->funcs->force_pstate_change_control) + dc->res_pool->hubbub->funcs->force_pstate_change_control( + dc->res_pool->hubbub, true, false); + udelay(500); + } + /* Set pipe update flags and lock pipes */ for (i = 0; i < dc->res_pool->pipe_count; i++) dcn20_detect_pipe_changes(&dc->current_state->res_ctx.pipe_ctx[i], @@ -2039,6 +2055,10 @@ void dcn20_post_unlock_program_front_end( } }
+ if (dc->res_pool->hubbub->funcs->force_pstate_change_control) + dc->res_pool->hubbub->funcs->force_pstate_change_control( + dc->res_pool->hubbub, false, false); + for (i = 0; i < dc->res_pool->pipe_count; i++) { struct pipe_ctx *pipe = &context->res_ctx.pipe_ctx[i];