sdio_readsb(9)

💅 sdio_readsb — like, the SDIO FIFO reader you've been waiting for

okay so bestie, welcome to sdio_readsb(9) from the Kernel API Manual — yes it's a kernel manpage, yes it's giving serious main character energy, and yes we're gonna get through it together 🫶✨

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✨ NAME ✨

sdio_readsb — read from a FIFO on a SDIO function

That's it. That's the whole vibe. You're reading bytes out of a FIFO that lives on an SDIO function. Slay 💅

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🌸 SYNOPSIS 🌸

int sdio_readsb (struct sdio_func *func , void *dst , unsigned int addr
, int count );

look at her. iconic signature. no notes 🔥

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🎀 ARGUMENTS 🎀

• func — the SDIO function you're accessing, like, the thing you're talking to 💖
• dst — the buffer where the data gets stored (this is where the goods land 🍓)
• addr — address of the (single byte) FIFO. yes, single byte, the original said it, so I'm saying it 🎯
• count — number of bytes to read, i.e. how much you're grabbing 🎀

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🦋 DESCRIPTION 🦋

So here's the tea ☕ — this function reads from the specified FIFO of a given SDIO function. That's the whole job. It's giving "I do one thing and I do it well" 💅

The return value tells you if the transfer succeeded or not. Success? Slay. Failure? Well. You'll know 😭 That's literally all the original says, and I'm not out here inventing lore, periodt.

ngl the whole thing is short and sweet — read the FIFO, return whether it worked. no cap, that's the entire plot 💀

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🌈 SEE ALSO 🌈

okay this list is LONG and honestly kind of iconic for it 👑

Kernel file ./drivers/mmc/core/sdio_io.c, plus these besties:

• sdio_claim_host(9)
• sdio_release_host(9)
• sdio_enable_func(9)
• sdio_disable_func(9)
• sdio_set_block_size(9)
• sdio_align_size(9)
• sdio_readb(9)
• sdio_writeb(9)
• sdio_writeb_readb(9)
• sdio_memcpy_fromio(9)
• sdio_memcpy_toio(9)
• sdio_writesb(9)
• sdio_readw(9)
• sdio_writew(9)
• sdio_readl(9)
• sdio_writel(9)
• sdio_f0_readb(9)
• sdio_f0_writeb(9)
• sdio_get_host_pm_caps(9)
• sdio_set_host_pm_flags(9)
• sdio_retune_crc_disable(9)
• sdio_retune_crc_enable(9)
• sdio_retune_hold_now(9)
• sdio_retune_release(9)

twenty-four besties in the group chat and every single one of them ate 💖✨

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and that's the whole page, bestie!! 🧚 from ./drivers/mmc/core, dated October 2026, page sdio_readsb(9) — go forth and read those FIFOs, you've got this 💜👑