[PATCH v10 11/69] drm/display: hdmi: Advertise SCDC source version when scrambling
Cristian Ciocaltea <[email protected]>
| Newsgroups | org.freedesktop.lists.dri-devel,dev.linux.lists.linux-sunxi,org.infradead.lists.linux-arm-kernel,org.infradead.lists.linux-rockchip,org.kernel.vger.linux-kernel |
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| Message-ID | <[email protected]> |
The HDMI 2.0 spec advises that compliant Source devices report their SCDC version in the Source Version register. Do so when enabling scrambling by calling drm_scdc_set_source_version(). Failures are non-fatal: SCDC version negotiation is purely informational and does not gate scrambling or any high-bitrate functionality, so a flaky DDC bus should not block scrambling setup. Acked-by: Maxime Ripard <[email protected]> Tested-by: Maud Spierings <[email protected]> Tested-by: Diederik de Haas <[email protected]> # NanoPC-T6 LTS, Rock 5B Signed-off-by: Cristian Ciocaltea <[email protected]> --- drivers/gpu/drm/display/drm_hdmi_helper.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/drivers/gpu/drm/display/drm_hdmi_helper.c b/drivers/gpu/drm/display/drm_hdmi_helper.c index cfecfef639ad..493f2728ab86 100644 --- a/drivers/gpu/drm/display/drm_hdmi_helper.c +++ b/drivers/gpu/drm/display/drm_hdmi_helper.c @@ -16,6 +16,7 @@ #include <drm/drm_print.h> #include <drm/drm_property.h> +#define DRM_HDMI_SCDC_SOURCE_VERSION 1 #define DRM_HDMI_SCDC_POLL_DELAY_MS 1000 static inline bool is_eotf_supported(u8 output_eotf, u8 sink_eotf) @@ -556,6 +557,12 @@ int drm_connector_hdmi_enable_scrambling(struct drm_connector *connector, if (!connector->ddc) return -EINVAL; + /* + * Advertise our SCDC source version. This is purely informational and + * does not gate scrambling, so failures are non-fatal. + */ + drm_scdc_set_source_version(connector, DRM_HDMI_SCDC_SOURCE_VERSION); + drm_dbg_kms(dev, "Enabling scrambling\n"); if (!hdmi->scdc_work_initialized) { -- 2.55.0