it821x_program_udma(9)

💖 NAME 💖

okay so bestie, this is it821x_program_udma — program the UDMA registers — from the Kernel API Manual as it821x_program_udma(9). ✨ It's giving low-level ATA timing realness, and honestly? Obsessed. 💅

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✨ SYNOPSIS ✨

the whole vibe check:

void it821x_program_udma (struct ata_port *ap , struct ata_device *adev
, u16 timing );

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🎀 ARGUMENTS 🎀

okay, meet the cast:

• ap — ATA port. 💖
• adev — ATA device to update. 🛠️
• timing — timing bits. Top 8 are for 66Mhz, bottom for 50Mhz. 👑

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🦋 DESCRIPTION 🦋

so what's the tea? ☕ It programs the UDMA timing for this drive according to the current clock. ⏰

It handles the dual clocks and also knows about the errata on the 0x10 revision — no cap, that revision is a whole situation. 😭 The UDMA errata is partly handled here and partly in start_dma, so this function is not out here doing the entire errata saga solo. 💅

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🌸 SEE ALSO 🌸

go look at these too, iykyk: 🌈

• Kernel file: ./drivers/ata/pata_it821x.c
• it821x_program(9)
• it821x_clock_strategy(9)
• it821x_passthru_set_piomode(9)
• it821x_passthru_set_dmamode(9)
• it821x_passthru_bmdma_start(9)
• it821x_passthru_bmdma_stop(9)
• it821x_passthru_dev_select(9)
• it821x_smart_qc_issue(9)
• it821x_passthru_qc_issue(9)
• it821x_smart_set_mode(9)
• it821x_dev_config(9)
• it821x_read_id(9)
• it821x_check_atapi_dma(9)
• it821x_display_disk(9)
• it821x_firmware_command(9)
• it821x_probe_firmware(9)
• it821x_port_start(9)
• it821x_rdc_cable(9)

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xoxo, your favorite kernel bestie 💅 — source ./drivers/ata, date October 2026, version it821x_program_udma(9). 🫶