From: Timur Kristóf Date: Tue, 28 Apr 2026 11:40:40 +0000 (+0200) Subject: drm/amd/display: Allow embedded connectors without DDC X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=75b8a6ca0e8bc3ce24572f854e95f8721b321179;p=thirdparty%2Fkernel%2Flinux.git drm/amd/display: Allow embedded connectors without DDC 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 --- diff --git a/drivers/gpu/drm/amd/display/dc/dc.h b/drivers/gpu/drm/amd/display/dc/dc.h index ca1b23a44e0a6..86da619c3721a 100644 --- a/drivers/gpu/drm/amd/display/dc/dc.h +++ b/drivers/gpu/drm/amd/display/dc/dc.h @@ -1686,7 +1686,7 @@ 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 a2c46350e44e8..95f8b7c7d657a 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 96a30c29b5e45..3b6ac8445e413 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; }