This is a note to let you know that I've just added the patch titled
drm/amd/display: Fix DSC not Enabled on Direct MST Sink
to the 6.6-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-fix-dsc-not-enabled-on-direct-mst-sink.patch
and it can be found in the queue-6.6 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From a58555359a9f870543aaddef277c3396159895ce Mon Sep 17 00:00:00 2001
From: Fangzhi Zuo <jerry.zuo@xxxxxxx>
Date: Mon, 23 Oct 2023 13:57:32 -0400
Subject: drm/amd/display: Fix DSC not Enabled on Direct MST Sink
From: Fangzhi Zuo <jerry.zuo@xxxxxxx>
commit a58555359a9f870543aaddef277c3396159895ce upstream.
[WHY & HOW]
For the scenario when a dsc capable MST sink device is directly
connected, it needs to use max dsc compression as the link bw constraint.
Cc: Mario Limonciello <mario.limonciello@xxxxxxx>
Cc: Alex Deucher <alexander.deucher@xxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Reviewed-by: Roman Li <roman.li@xxxxxxx>
Acked-by: Alex Hung <alex.hung@xxxxxxx>
Signed-off-by: Fangzhi Zuo <jerry.zuo@xxxxxxx>
Tested-by: Daniel Wheeler <daniel.wheeler@xxxxxxx>
Signed-off-by: Alex Deucher <alexander.deucher@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c | 29 +++++-------
1 file changed, 14 insertions(+), 15 deletions(-)
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c
@@ -1598,31 +1598,31 @@ enum dc_status dm_dp_mst_is_port_support
unsigned int upper_link_bw_in_kbps = 0, down_link_bw_in_kbps = 0;
unsigned int max_compressed_bw_in_kbps = 0;
struct dc_dsc_bw_range bw_range = {0};
- struct drm_dp_mst_topology_mgr *mst_mgr;
+ uint16_t full_pbn = aconnector->mst_output_port->full_pbn;
/*
- * check if the mode could be supported if DSC pass-through is supported
- * AND check if there enough bandwidth available to support the mode
- * with DSC enabled.
+ * Consider the case with the depth of the mst topology tree is equal or less than 2
+ * A. When dsc bitstream can be transmitted along the entire path
+ * 1. dsc is possible between source and branch/leaf device (common dsc params is possible), AND
+ * 2. dsc passthrough supported at MST branch, or
+ * 3. dsc decoding supported at leaf MST device
+ * Use maximum dsc compression as bw constraint
+ * B. When dsc bitstream cannot be transmitted along the entire path
+ * Use native bw as bw constraint
*/
if (is_dsc_common_config_possible(stream, &bw_range) &&
- aconnector->mst_output_port->passthrough_aux) {
- mst_mgr = aconnector->mst_output_port->mgr;
- mutex_lock(&mst_mgr->lock);
-
+ (aconnector->mst_output_port->passthrough_aux ||
+ aconnector->dsc_aux == &aconnector->mst_output_port->aux)) {
cur_link_settings = stream->link->verified_link_cap;
upper_link_bw_in_kbps = dc_link_bandwidth_kbps(aconnector->dc_link,
- &cur_link_settings
- );
- down_link_bw_in_kbps = kbps_from_pbn(aconnector->mst_output_port->full_pbn);
+ &cur_link_settings);
+ down_link_bw_in_kbps = kbps_from_pbn(full_pbn);
/* pick the bottleneck */
end_to_end_bw_in_kbps = min(upper_link_bw_in_kbps,
down_link_bw_in_kbps);
- mutex_unlock(&mst_mgr->lock);
-
/*
* use the maximum dsc compression bandwidth as the required
* bandwidth for the mode
@@ -1637,8 +1637,7 @@ enum dc_status dm_dp_mst_is_port_support
/* check if mode could be supported within full_pbn */
bpp = convert_dc_color_depth_into_bpc(stream->timing.display_color_depth) * 3;
pbn = drm_dp_calc_pbn_mode(stream->timing.pix_clk_100hz / 10, bpp, false);
-
- if (pbn > aconnector->mst_output_port->full_pbn)
+ if (pbn > full_pbn)
return DC_FAIL_BANDWIDTH_VALIDATE;
}
Patches currently in stable-queue which might be from jerry.zuo@xxxxxxx are
queue-6.6/drm-amd-display-fix-dsc-not-enabled-on-direct-mst-sink.patch
