dce8_bandwidth_update(9)

💅 dce8_bandwidth_update(9) — Kernel API Manual, but make it make sense

okay so bestie, welcome to the dce8_bandwidth_update page from the Kernel API Manual ✨ this is a tiny one but she's important, and I'm gonna walk you through it like we're texting at 2am 🫶

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🌸 NAME 🌸

dce8_bandwidth_update — literally just here to program display watermarks 👑

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✨ SYNOPSIS ✨

void dce8_bandwidth_update (struct radeon_device *rdev );

no return value, no drama, she does her thing and dips 💅

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🎀 ARGUMENTS 🎀

• rdev — a radeon_device pointer. that's it, that's the whole argument, she's low maintenance 💖

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🦋 DESCRIPTION 🦋

so what she actually does: she calculates and programs the display watermarks and the line buffer allocation. and yes, this is the CIK flavour of the situation 👑 no cap.

calculate 🧮 then program 💾 — both, in one function call. iconic.

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🌈 SEE ALSO 🌈

okay this part is long, buckle up 🎢 everything below is (9) section, and the kernel file lives at ./drivers/gpu/drm/radeon/cik.c 💜

the CIK basics, part one 🍓

• 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)

ring emission squad 🧚

• 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)

CP gfx + compute girlies 🔥

• 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)

reset / lockup behaviour (aka the messy part 😭)

• cik_gpu_check_soft_reset(9)
• cik_gpu_soft_reset(9)
• cik_asic_reset(9)
• cik_gfx_is_lockup(9)

memory + GART 🎀

• 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)

RLC ✨

• cik_rlc_stop(9)
• cik_rlc_start(9)
• cik_rlc_resume(9)

interrupts, the whole saga 💀

• 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)

lifecycle besties 🌸

• cik_startup(9)
• cik_resume(9)
• cik_suspend(9)
• cik_init(9)
• cik_fini(9)

and now — the bandwidth/watermark section, aka her actual friend group 💖

• dce8_line_buffer_adjust(9)
• cik_get_number_of_dram_channels(9)
• dce8_dram_bandwidth(9)
• dce8_dram_bandwidth_for_display(9)
• dce8_data_return_bandwidth(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)

and one (1) little clock counter friend ⭐

• cik_get_gpu_clock_counter(9)

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ngl the SEE ALSO list is giving "group project where everyone shows up" — but every single entry is a real one, so keep them all 💅

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💜 cute sign-off 💜

this page lives under ./drivers/gpu/drm/radeon, and the version vibes are dated October 2026 🗓️✨ that's the whole page bestie, go program some watermarks, ily, mwah 🫶🎀🦋