Hi Neil, Andrzej, Robert On 31/10/25 20:40, Tomi Valkeinen wrote:
Hi, On 30/10/2025 17:16, Devarsh Thakkar wrote:The sii902x driver was caching HDMI detection state in a sink_is_hdmi field and checking it in mode_set() to determine whether to set HDMI or DVI output mode. This approach had two problems: 1. With DRM_BRIDGE_ATTACH_NO_CONNECTOR (used by modern display drivers like TIDSS), the bridge's get_modes() is never called. Instead, the drm_bridge_connector helper calls the bridge's edid_read() and updates the connector itself. This meant sink_is_hdmi was never populated, causing the driver to default to DVI mode and breaking HDMI audio. 2. The mode_set() callback doesn't receive atomic state or connector pointer, making it impossible to check connector->display_info.is_hdmi directly at that point. Fix this by moving the HDMI vs DVI decision from mode_set() to atomic_enable(), where we can access the connector via drm_atomic_get_new_connector_for_encoder(). This works for both connector models: - With DRM_BRIDGE_ATTACH_NO_CONNECTOR: Returns the drm_bridge_connector created by the display driver, which has already been updated by the helper's call to drm_edid_connector_update() - Without DRM_BRIDGE_ATTACH_NO_CONNECTOR (legacy): Returns the connector embedded in sii902x struct, which gets updated by the bridge's own get_modes() Fixes: 3de47e1309c2 ("drm/bridge: sii902x: use display info is_hdmi") Signed-off-by: Devarsh Thakkar <[email protected]> --- V4: Shift HDMI detection to atomic_enable() and remove sink_is_hdmi caching V3: Use drm_edid_connector_update without edid NULL check V2: Use drm_edid_connector_update to detect HDMI
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Reviewed-by: Tomi Valkeinen <[email protected]>
I wanted to follow up on this patch which fixes HDMI audio for the sii902x bridge driver when used with DRM_BRIDGE_ATTACH_NO_CONNECTOR. The patch has been reviewed by Tomi Valkeinen and addresses a real bug where HDMI audio is broken when using modern display drivers like TIDSS.
Could you please let me know if there are any concerns or if this can be pulled in ? Regards Devarsh
