From: Timur Kristóf <timur.kristof@gmail.com>
Date: Mon, 26 Jan 2026 21:08:31 +0000 (+0100)
Subject: drm/amd/display: Add ability for HWSS to prepare the DDC before use
X-Git-Tag: v7.1-rc1~167^2~31^2~117
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=05a606fc39840257b66bbe3bafef733218657304;p=thirdparty%2Fkernel%2Flinux.git

drm/amd/display: Add ability for HWSS to prepare the DDC before use

Make it possible to add a HWSS function to prepare the DDC
before trying to use it. This is going to be necessary for
external DP bridge encoders.

This commit just adds the function to common DC code.
The actual implementation of this function for DCE is
done in a subsequent commit.

Signed-off-by: Timur Kristóf <timur.kristof@gmail.com>
Reviewed-by: Alex Hung <alex.hung@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
---

diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c
index a09761f9882d1..71cfc623bc2d4 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c
@@ -1016,6 +1016,9 @@ enum dc_edid_status dm_helpers_read_local_edid(
 	else
 		ddc = &aconnector->i2c->base;
 
+	if (link->dc->hwss.prepare_ddc)
+		link->dc->hwss.prepare_ddc(link);
+
 	/* some dongles read edid incorrectly the first time,
 	 * do check sum and retry to make sure read correct edid.
 	 */
diff --git a/drivers/gpu/drm/amd/display/dc/hwss/hw_sequencer.h b/drivers/gpu/drm/amd/display/dc/hwss/hw_sequencer.h
index d3d35912349d8..d1796e07ab1a3 100644
--- a/drivers/gpu/drm/amd/display/dc/hwss/hw_sequencer.h
+++ b/drivers/gpu/drm/amd/display/dc/hwss/hw_sequencer.h
@@ -1190,6 +1190,7 @@ struct hw_sequencer_funcs {
 			const struct link_resource *link_res,
 			enum signal_type signal);
 	bool (*dac_load_detect)(struct dc_link *link);
+	void (*prepare_ddc)(struct dc_link *link);
 
 	void (*get_dcc_en_bits)(struct dc *dc, int *dcc_en_bits);
 
diff --git a/drivers/gpu/drm/amd/display/dc/link/link_detection.c b/drivers/gpu/drm/amd/display/dc/link/link_detection.c
index 8fd796d987b63..2d1f3d13c1773 100644
--- a/drivers/gpu/drm/amd/display/dc/link/link_detection.c
+++ b/drivers/gpu/drm/amd/display/dc/link/link_detection.c
@@ -912,6 +912,9 @@ static bool link_detect_ddc_probe(struct dc_link *link)
 	if (!link->ddc)
 		return false;
 
+	if (link->dc->hwss.prepare_ddc)
+		link->dc->hwss.prepare_ddc(link);
+
 	set_ddc_transaction_type(link->ddc, transaction_type);
 
 	ddc_probed = link_query_ddc_data(link->ddc, 0x50, &zero, 1, edid_header, sizeof(edid_header));