__ssp_wait_for_xmitr(9)

💜 __ssp_wait_for_xmitr — a Kernel API Manual moment (section 9, bestie)

Okay so we're in the Kernel API Manual, section 9, and today's main character is __ssp_wait_for_xmitr. Yes the double underscore is part of the name, no we're not dropping it, it's iconic actually 💅

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✨ NAME ✨

__ssp_wait_for_xmitr — literally just vibing until there's an empty slot on the TX FIFO 🎀

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🌸 SYNOPSIS 🌸

void __ssp_wait_for_xmitr (struct sifive_serial_port *ssp );

That's it. That's the whole call. No return value, no drama, just a void and a pointer. Periodt.

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🦋 ARGUMENTS 🦋

• ssp — pointer to a struct sifive_serial_port. That's your whole personality for this function bestie, that's the thing you hand over 🫶

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⭐ DESCRIPTION ⭐

So what it does: it delays while the UART TX FIFO that ssp points at is marked as full. That's the entire gig. It waits. It does not transmit, it does not compute, it does not slay in any productive sense — it just hangs out and waits for the FIFO to not be full anymore 🙈

Think of it like standing outside a packed club waiting for someone to leave. Except the club is a FIFO and you're kernel code. Same energy tbh.

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🌈 CONTEXT 🌈

Any context. Fr fr, no restrictions — call it whenever, wherever, the function is not picky 💀

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👑 SEE ALSO 👑

Grab a snack bestie, this list is long and honestly kind of a flex. All of these live in the kernel file ./drivers/tty/serial/sifive.c:

• struct sifive_serial_port(9)
• __ssp_early_writel(9)
• __ssp_early_readl(9)
• __ssp_writel(9)
• __ssp_readl(9)
• sifive_serial_is_txfifo_full(9)
• __ssp_transmit_char(9)
• __ssp_transmit_chars(9)
• __ssp_enable_txwm(9)
• __ssp_enable_rxwm(9)
• __ssp_disable_txwm(9)
• __ssp_disable_rxwm(9)
• __ssp_receive_char(9)
• __ssp_receive_chars(9)
• __ssp_update_div(9)
• __ssp_update_baud_rate(9)
• __ssp_set_stop_bits(9)
• sifive_serial_clk_notifier(9)

That is a lot of __ssp_ names and every single one of them is correct, don't @ me 🍓

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Okay that's the page!! Big kiss to ./drivers/tty/serial for hosting this whole saga, and the date on the calendar when this dropped was October 2026 ✨ Bye bestie, go wait on a FIFO responsibly 💖