The patch below does not apply to the 6.10-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.10.y git checkout FETCH_HEAD git cherry-pick -x d03415f60b3401914fabd27a20017f8056fd5e40 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to 'stable@vger.kernel.org' --in-reply-to '2024081219-deforest-viscous-3723@gregkh' --subject-prefix 'PATCH 6.10.y' HEAD^..

Possible dependencies:

d03415f60b34 ("drm/amd/display: Send DP_TOTAL_LTTPR_CNT during detection if LTTPR is present")

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From d03415f60b3401914fabd27a20017f8056fd5e40 Mon Sep 17 00:00:00 2001 From: Michael Strauss michael.strauss@amd.com Date: Tue, 28 Nov 2023 10:31:12 -0500 Subject: [PATCH] drm/amd/display: Send DP_TOTAL_LTTPR_CNT during detection if LTTPR is present

[WHY] New register field added in DP2.1 SCR, needed for auxless ALPM

[HOW] Echo value read from 0xF0007 back to sink

Reviewed-by: Wenjing Liu wenjing.liu@amd.com Cc: Mario Limonciello mario.limonciello@amd.com Cc: Alex Deucher alexander.deucher@amd.com Cc: stable@vger.kernel.org Signed-off-by: Alex Hung alex.hung@amd.com Signed-off-by: Michael Strauss michael.strauss@amd.com Tested-by: Daniel Wheeler daniel.wheeler@amd.com Signed-off-by: Alex Deucher alexander.deucher@amd.com

diff --git a/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_capability.c b/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_capability.c index 00974c50e11f..f1cac74dd7f7 100644 --- a/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_capability.c +++ b/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_capability.c @@ -1605,9 +1605,17 @@ static bool retrieve_link_cap(struct dc_link *link) return false; }

- if (dp_is_lttpr_present(link)) + if (dp_is_lttpr_present(link)) { configure_lttpr_mode_transparent(link);

+ // Echo TOTAL_LTTPR_CNT back downstream + core_link_write_dpcd( + link, + DP_TOTAL_LTTPR_CNT, + &link->dpcd_caps.lttpr_caps.phy_repeater_cnt, + sizeof(link->dpcd_caps.lttpr_caps.phy_repeater_cnt)); + } + /* Read DP tunneling information. */ status = dpcd_get_tunneling_device_data(link);

diff --git a/drivers/gpu/drm/amd/display/include/dpcd_defs.h b/drivers/gpu/drm/amd/display/include/dpcd_defs.h index 914f28e9f224..aee5170f5fb2 100644 --- a/drivers/gpu/drm/amd/display/include/dpcd_defs.h +++ b/drivers/gpu/drm/amd/display/include/dpcd_defs.h @@ -177,4 +177,9 @@ enum dpcd_psr_sink_states { #define DP_SINK_PR_PIXEL_DEVIATION_PER_LINE 0x379 #define DP_SINK_PR_MAX_NUMBER_OF_DEVIATION_LINE 0x37A

+/* Remove once drm_dp_helper.h is updated upstream */ +#ifndef DP_TOTAL_LTTPR_CNT +#define DP_TOTAL_LTTPR_CNT 0xF000A /* 2.1 */ +#endif + #endif /* __DAL_DPCD_DEFS_H__ */