This is a note to let you know that I've just added the patch titled
drm/amd/display: Block optimize on consecutive FAMS enables
to the 6.5-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
drm-amd-display-block-optimize-on-consecutive-fams-enables.patch
and it can be found in the queue-6.5 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 3b6df06f01cdbff3b610b492ad4879691afdc70d Mon Sep 17 00:00:00 2001
From: Wesley Chalmers <Wesley.Chalmers@xxxxxxx>
Date: Wed, 31 May 2023 13:29:34 -0400
Subject: drm/amd/display: Block optimize on consecutive FAMS enables
From: Wesley Chalmers <Wesley.Chalmers@xxxxxxx>
commit 3b6df06f01cdbff3b610b492ad4879691afdc70d upstream.
[WHY]
It is possible to commit state multiple times in rapid succession with
FAMS enabled; if each of these commits were to set optimized_required,
then the user may see latency.
[HOW]
fw_based_mclk_switching is currently not used in dc->clk_mgr; use it
to track whether the current state has FAMS enabled;
if it has, then do not disable FAMS in prepare_bandwidth, and do not set
optimized_required.
Reviewed-by: Rodrigo Siqueira <Rodrigo.Siqueira@xxxxxxx>
Signed-off-by: Wesley Chalmers <Wesley.Chalmers@xxxxxxx>
Tested-by: Daniel Wheeler <daniel.wheeler@xxxxxxx>
Signed-off-by: Alex Deucher <alexander.deucher@xxxxxxx>
Acked-by: Hamza Mahfooz <hamza.mahfooz@xxxxxxx>
Signed-off-by: Alex Deucher <alexander.deucher@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/gpu/drm/amd/display/dc/dcn20/dcn20_hwseq.c | 3 ++
drivers/gpu/drm/amd/display/dc/dcn30/dcn30_hwseq.c | 22 ++++++++++++++++++---
2 files changed, 22 insertions(+), 3 deletions(-)
--- a/drivers/gpu/drm/amd/display/dc/dcn20/dcn20_hwseq.c
+++ b/drivers/gpu/drm/amd/display/dc/dcn20/dcn20_hwseq.c
@@ -2127,6 +2127,9 @@ void dcn20_optimize_bandwidth(
dc_dmub_srv_p_state_delegate(dc,
true, context);
context->bw_ctx.bw.dcn.clk.p_state_change_support = true;
+ dc->clk_mgr->clks.fw_based_mclk_switching = true;
+ } else {
+ dc->clk_mgr->clks.fw_based_mclk_switching = false;
}
dc->clk_mgr->funcs->update_clocks(
--- a/drivers/gpu/drm/amd/display/dc/dcn30/dcn30_hwseq.c
+++ b/drivers/gpu/drm/amd/display/dc/dcn30/dcn30_hwseq.c
@@ -949,9 +949,13 @@ void dcn30_set_disp_pattern_generator(co
}
void dcn30_prepare_bandwidth(struct dc *dc,
- struct dc_state *context)
+ struct dc_state *context)
{
- if (context->bw_ctx.bw.dcn.clk.fw_based_mclk_switching) {
+ bool p_state_change_support = context->bw_ctx.bw.dcn.clk.p_state_change_support;
+ /* Any transition into an FPO config should disable MCLK switching first to avoid
+ * driver and FW P-State synchronization issues.
+ */
+ if (context->bw_ctx.bw.dcn.clk.fw_based_mclk_switching || dc->clk_mgr->clks.fw_based_mclk_switching) {
dc->optimized_required = true;
context->bw_ctx.bw.dcn.clk.p_state_change_support = false;
}
@@ -962,7 +966,19 @@ void dcn30_prepare_bandwidth(struct dc *
dc->clk_mgr->funcs->set_max_memclk(dc->clk_mgr, dc->clk_mgr->bw_params->clk_table.entries[dc->clk_mgr->bw_params->clk_table.num_entries - 1].memclk_mhz);
dcn20_prepare_bandwidth(dc, context);
+ /*
+ * enabled -> enabled: do not disable
+ * enabled -> disabled: disable
+ * disabled -> enabled: don't care
+ * disabled -> disabled: don't care
+ */
+ if (!context->bw_ctx.bw.dcn.clk.fw_based_mclk_switching)
+ dc_dmub_srv_p_state_delegate(dc, false, context);
- dc_dmub_srv_p_state_delegate(dc, false, context);
+ if (context->bw_ctx.bw.dcn.clk.fw_based_mclk_switching || dc->clk_mgr->clks.fw_based_mclk_switching) {
+ /* After disabling P-State, restore the original value to ensure we get the correct P-State
+ * on the next optimize. */
+ context->bw_ctx.bw.dcn.clk.p_state_change_support = p_state_change_support;
+ }
}
Patches currently in stable-queue which might be from Wesley.Chalmers@xxxxxxx are
queue-6.5/drm-amd-display-block-optimize-on-consecutive-fams-enables.patch
queue-6.5/drm-amd-display-do-not-set-drr-on-pipe-commit.patch
