From 494941aa772dab79251543764db6cd14bd337e43 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Timur=20Krist=C3=B3f?= Date: Tue, 28 Apr 2026 13:40:40 +0200 Subject: drm/amd/display: Allow embedded connectors without DDC MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit On some laptops, the embedded panel may not have a DDC (display data channel) available. On these, the EDID may be hardcoded in ACPI or the VBIOS. In this case, use GPIO_DDC_LINE_UNKNOWN and don't fail. Fixes: def3488eb0fd ("drm/amd/display: refactor HPD to increase flexibility") Link: https://gitlab.freedesktop.org/drm/amd/-/work_items/5192 Signed-off-by: Timur Kristóf Signed-off-by: Alex Deucher (cherry picked from commit 75b8a6ca0e8bc3ce24572f854e95f8721b321179) --- drivers/gpu/drm/amd/display/dc/dc.h | 2 +- drivers/gpu/drm/amd/display/dc/gpio/gpio_service.c | 3 +++ drivers/gpu/drm/amd/display/dc/link/link_factory.c | 4 +++- 3 files changed, 7 insertions(+), 2 deletions(-) (limited to 'drivers') diff --git a/drivers/gpu/drm/amd/display/dc/dc.h b/drivers/gpu/drm/amd/display/dc/dc.h index 7f55ba09b191..37714d4371fb 100644 --- a/drivers/gpu/drm/amd/display/dc/dc.h +++ b/drivers/gpu/drm/amd/display/dc/dc.h @@ -1682,7 +1682,7 @@ struct dc_scratch_space { struct dc_link_training_overrides preferred_training_settings; struct dp_audio_test_data audio_test_data; - uint8_t ddc_hw_inst; + enum gpio_ddc_line ddc_hw_inst; uint8_t hpd_src; diff --git a/drivers/gpu/drm/amd/display/dc/gpio/gpio_service.c b/drivers/gpu/drm/amd/display/dc/gpio/gpio_service.c index a2c46350e44e..95f8b7c7d657 100644 --- a/drivers/gpu/drm/amd/display/dc/gpio/gpio_service.c +++ b/drivers/gpu/drm/amd/display/dc/gpio/gpio_service.c @@ -646,6 +646,9 @@ failure: enum gpio_ddc_line dal_ddc_get_line( const struct ddc *ddc) { + if (!ddc) + return GPIO_DDC_LINE_UNKNOWN; + return (enum gpio_ddc_line)dal_gpio_get_enum(ddc->pin_data); } diff --git a/drivers/gpu/drm/amd/display/dc/link/link_factory.c b/drivers/gpu/drm/amd/display/dc/link/link_factory.c index 7e7682d7dfc8..ae4c4ad05baa 100644 --- a/drivers/gpu/drm/amd/display/dc/link/link_factory.c +++ b/drivers/gpu/drm/amd/display/dc/link/link_factory.c @@ -568,7 +568,9 @@ static bool construct_phy(struct dc_link *link, goto ddc_create_fail; } - if (!link->ddc->ddc_pin) { + /* Embedded display connectors such as LVDS may not have DDC. */ + if (!link->ddc->ddc_pin && + !dc_is_embedded_signal(link->connector_signal)) { DC_ERROR("Failed to get I2C info for connector!\n"); goto ddc_create_fail; } -- cgit v1.2.3