drm_dp_tunn...k_stream_bws(9)

💅 drm_dp_tunnel_atomic_check_stream_bws 💅

okay bestie, this page is drm_dp_tunn...k_stream_bws(9) from the Kernel API Manual — yes the header name is literally truncated like that, no cap. let’s get into it 🫶

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✨ NAME ✨

drm_dp_tunnel_atomic_check_stream_bws — Check BW limit for all streams in state

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🦋 SYNOPSIS 🦋

int drm_dp_tunnel_atomic_check_stream_bws (struct drm_atomic_commit
       *state , u32 *failed_stream_mask );

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🎀 ARGUMENTS 🎀

• state — Atomic state
• failed_stream_mask — Mask of stream IDs with a BW limit failure

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🌸 DESCRIPTION 🌸

okay so what this function does is check the required BW of each DP tunnel in state against both the DPRX BW limit of the tunnel and the BW limit of the tunnel group. once a check fails, it returns a mask of stream IDs in failed_stream_mask. that mask will contain either all the streams in a tunnel (in case a DPRX BW limit check failed) or all the streams in a tunnel group (in case a group BW limit check failed). 💅

return 0 if all the BW limit checks passed, -ENOSPC in case a BW limit check failed — with failed_stream_mask containing the streams failing the check — or a negative error code otherwise. periodt. 🔥

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🔥 SEE ALSO 🔥

• Kernel file: ./drivers/gpu/drm/display/drm_dp_tunnel.c
• drm_dp_tunnel_get(9)
• drm_dp_tunnel_put(9)
• drm_dp_tunnel_set_io_error(9)
• drm_dp_tunnel_detect(9)
• drm_dp_tunnel_destroy(9)
• drm_dp_tunnel_enable_bw_alloc(9)
• drm_dp_tunnel_disable_bw_alloc(9)
• drm_dp_tunnel_bw_alloc_is_enabled(9)
• drm_dp_tunnel_pr_optimization_supported(9)
• drm_dp_tunnel_alloc_bw(9)
• drm_dp_tunnel_get_allocated_bw(9)
• drm_dp_tunnel_update_state(9)
• drm_dp_tunnel_128b132b_supported(9)
• drm_dp_tunnel_128b132b_lane0_mapping_supported(9)
• drm_dp_tunnel_128b132b_dprx_rates(9)
• drm_dp_tunnel_max_dprx_rate(9)
• drm_dp_tunnel_max_dprx_lane_count(9)
• drm_dp_tunnel_available_bw(9)
• drm_dp_tunnel_atomic_get_state(9)
• drm_dp_tunnel_atomic_get_old_state(9)
• drm_dp_tunnel_atomic_get_new_state(9)
• drm_dp_tunnel_atomic_set_stream_bw(9)
• drm_dp_tunnel_atomic_get_required_bw(9)
• drm_dp_tunnel_atomic_get_group_streams_in_state(9)
• drm_dp_tunnel_mgr_create(9)
• drm_dp_tunnel_mgr_destroy(9)

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that’s the whole vibe, mwah 💋 this was drm_dp_tunn...k_stream_bws(9) from the Kernel API Manual, sourced from ./drivers/gpu/drm/display, dated October 2026. ily, bye! 💖