pdc2026x_bmdma_start(9)

✨ pdc2026x_bmdma_start (9) ✨

okay so bestie, welcome to the kernel API manual 💖 this one's from the Kernel API Manual, and it's literally all about kicking off a DMA transfer. buckle up 🎀

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🌸 NAME 🌸

pdc2026x_bmdma_start — DMA engine begin ✨ like, the moment the DMA engine wakes up and gets going 💅

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🦋 SYNOPSIS 🦋

void pdc2026x_bmdma_start (struct ata_queued_cmd *qc );

no cap, that's the whole signature — returns void, takes exactly one thing 🫶

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🎀 ARGUMENTS 🎀

• qc — an ATA command. that's it, that's the parameter 💖 it's a struct ata_queued_cmd *, so it's a pointer, and it's the command we're about to send ✨

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💅 DESCRIPTION 💅

so here's the vibe: when you're running UDMA3 or higher, you have to do a clock switch for the whole duration of the DMA transfer sequence 🔥 that's literally the entire reason this function exists, bestie — the timing has to be right or the whole thing falls apart 😭

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🌈 NOTE 🌈

the host lock held by the libata layer is out here doing the lord's work 🙏 it protects us from two channels both trying to set DMA bits at once — imagine the chaos 💀 iconic of libata honestly 👑

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⭐ SEE ALSO ⭐

• Kernel file ./drivers/ata/pata_pdc202xx_old.c — the main character 🫶
• pdc202xx_configure_piomode(9)
• pdc202xx_set_piomode(9)
• pdc202xx_set_dmamode(9)
• pdc2026x_bmdma_stop(9) — the sequel, the shutdown arc 🎬
• pdc2026x_dev_config(9)
• pdc2026x_check_atapi_dma(9)

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okay that's the whole page, go read the source fr fr 💜

sign-off szn: this absolute banger lives in ./drivers/ata, and we're stamping it October 2026 🌸 mwah, bye bestie 💋✨