From 6b5d7730d226bed8e87085d870e76fb9018ff0b1 Mon Sep 17 00:00:00 2001 From: Noah Abradjian Date: Mon, 18 Nov 2019 13:59:57 -0500 Subject: [PATCH] drm/amd/display: Add wait for flip not pending on pipe unlock [Why] Lack of proper timing caused intermittent underflow on unplug external DP. A previous fix was invalid and caused S0i3 regression, so had to be reverted. [How] When unlocking pipe, wait for no pipes to have flip pending before unlocking. Signed-off-by: Noah Abradjian Reviewed-by: Tony Cheng Acked-by: Rodrigo Siqueira Signed-off-by: Alex Deucher --- drivers/gpu/drm/amd/display/dc/core/dc.c | 39 ++++++++++++++++++++++-- 1 file changed, 36 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/amd/display/dc/core/dc.c b/drivers/gpu/drm/amd/display/dc/core/dc.c index 39fe38cb39b6..879cedd79d9e 100644 --- a/drivers/gpu/drm/amd/display/dc/core/dc.c +++ b/drivers/gpu/drm/amd/display/dc/core/dc.c @@ -66,6 +66,9 @@ #include "dce/dce_i2c.h" +#define CTX \ + dc->ctx + #define DC_LOGGER \ dc->ctx->logger @@ -783,6 +786,33 @@ static void disable_dangling_plane(struct dc *dc, struct dc_state *context) dc_release_state(current_ctx); } +static void wait_for_no_pipes_pending(struct dc *dc, struct dc_state *context) +{ + int i; + int count = 0; + struct pipe_ctx *pipe; + PERF_TRACE(); + for (i = 0; i < MAX_PIPES; i++) { + pipe = &context->res_ctx.pipe_ctx[i]; + + if (!pipe->plane_state) + continue; + + /* Timeout 100 ms */ + while (count < 100000) { + /* Must set to false to start with, due to OR in update function */ + pipe->plane_state->status.is_flip_pending = false; + dc->hwss.update_pending_status(pipe); + if (!pipe->plane_state->status.is_flip_pending) + break; + udelay(1); + count++; + } + ASSERT(!pipe->plane_state->status.is_flip_pending); + } + PERF_TRACE(); +} + /******************************************************************************* * Public functions ******************************************************************************/ @@ -1224,9 +1254,12 @@ static enum dc_status dc_commit_state_no_check(struct dc *dc, struct dc_state *c dc_enable_stereo(dc, context, dc_streams, context->stream_count); - if (!dc->optimize_seamless_boot) - /* pplib is notified if disp_num changed */ - dc->hwss.optimize_bandwidth(dc, context); + if (!dc->optimize_seamless_boot) { + /* Must wait for no flips to be pending before doing optimize bw */ + wait_for_no_pipes_pending(dc, context); + /* pplib is notified if disp_num changed */ + dc->hwss.optimize_bandwidth(dc, context); + } for (i = 0; i < context->stream_count; i++) context->streams[i]->mode_changed = false; -- 2.45.2