dce8_data_return_bandwidth(9)

✨ dce8_data_return_bandwidth(9) ✨

okay so bestie, this one's from the Kernel API Manual and it is literally the glow-up guide for your display's bandwidth math 💅 buckle up.

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💖 NAME 💖

dce8_data_return_bandwidth — get the data return bandwidth 🫶

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✨ SYNOPSIS ✨

u32 dce8_data_return_bandwidth (struct dce8_wm_params *wm );

like, it hands you back a u32, no cap 🔥

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🌸 ARGUMENTS 🌸

• wm — the watermark calculation data 🎀 this is the little struct carrying all the numbers the math needs, she's the main character here

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🦋 DESCRIPTION 🦋

So what she does: she calculates the data return bandwidth used for display (that's CIK, iykyk). This is the number that gets used for display watermark bandwidth calculations 💫

And what you get back? The data return bandwidth, measured in MBytes/s ⭐ so yeah, she does the math and tells you how much bandwidth is coming back at you, in megabytes per second, periodt.

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👑 SEE ALSO 👑

First up, the actual kernel file she lives in:

• Kernel file ./drivers/gpu/drm/radeon/cik.c

and then the whole friend group, fr fr — every single one of these:

• cik_get_allowed_info_register(9)
• cik_get_xclk(9)
• cik_mm_rdoorbell(9)
• cik_mm_wdoorbell(9)
• cik_srbm_select(9)
• ci_mc_load_microcode(9)
• cik_init_microcode(9)
• cik_tiling_mode_table_init(9)
• cik_select_se_sh(9)
• cik_create_bitmask(9)
• cik_get_rb_disabled(9)
• cik_setup_rb(9)
• cik_gpu_init(9)
• cik_scratch_init(9)
• cik_ring_test(9)
• cik_hdp_flush_cp_ring_emit(9)
• cik_fence_gfx_ring_emit(9)
• cik_fence_compute_ring_emit(9)
• cik_semaphore_ring_emit(9)
• cik_copy_cpdma(9)
• cik_ring_ib_execute(9)
• cik_ib_test(9)
• cik_cp_gfx_enable(9)
• cik_cp_gfx_load_microcode(9)
• cik_cp_gfx_start(9)
• cik_cp_gfx_fini(9)
• cik_cp_gfx_resume(9)
• cik_cp_compute_enable(9)
• cik_cp_compute_load_microcode(9)
• cik_cp_compute_start(9)
• cik_cp_compute_fini(9)
• cik_cp_compute_resume(9)
• cik_gpu_check_soft_reset(9)
• cik_gpu_soft_reset(9)
• cik_asic_reset(9)
• cik_gfx_is_lockup(9)
• cik_mc_program(9)
• cik_mc_init(9)
• cik_pcie_gart_tlb_flush(9)
• cik_pcie_gart_enable(9)
• cik_pcie_gart_disable(9)
• cik_pcie_gart_fini(9)
• cik_ib_parse(9)
• cik_vm_init(9)
• cik_vm_fini(9)
• cik_vm_decode_fault(9)
• cik_rlc_stop(9)
• cik_rlc_start(9)
• cik_rlc_resume(9)
• cik_enable_interrupts(9)
• cik_disable_interrupts(9)
• cik_disable_interrupt_state(9)
• cik_irq_init(9)
• cik_irq_set(9)
• cik_irq_ack(9)
• cik_irq_disable(9)
• cik_irq_suspend(9)
• cik_irq_fini(9)
• cik_get_ih_wptr(9)
• cik_irq_process(9)
• cik_startup(9)
• cik_resume(9)
• cik_suspend(9)
• cik_init(9)
• cik_fini(9)
• dce8_line_buffer_adjust(9)
• cik_get_number_of_dram_channels(9)
• dce8_dram_bandwidth(9)
• dce8_dram_bandwidth_for_display(9)
• dce8_dmif_request_bandwidth(9)
• dce8_available_bandwidth(9)
• dce8_average_bandwidth(9)
• dce8_latency_watermark(9)
• dce8_average_bandwidth_vs_dram_bandwidth_for_display(9)
• dce8_average_bandwidth_vs_available_bandwidth(9)
• dce8_check_latency_hiding(9)
• dce8_program_watermarks(9)
• dce8_bandwidth_update(9)
• cik_get_gpu_clock_counter(9)

like… that's the whole squad 😭💀

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🎀 cute lil sign-off: this page is from ./drivers/gpu/drm/radeon, dated October 2026, and yes she's filed under dce8_data_return_bandwidth(9) because obviously 💜 go read it again if you need to, bestie 🧚💖