__ssp_disable_txwm(9)

💅 __ssp_disable_txwm

okay so bestie, welcome to the Kernel API Manual — this one's a lil function from the SiFive UART driver and it's honestly so chill. Let's get into it ✨

---

✨ NAME ✨

__ssp_disable_txwm — literally just turns OFF transmit watermark interrupts. that's it. that's the whole vibe 🎀

---

🦋 SYNOPSIS 🦋

void __ssp_disable_txwm (struct sifive_serial_port *ssp );

no return value, nothing comes back, she just does her thing and leaves 💅

---

🌸 ARGUMENTS 🌸

• ssp — a pointer to a struct sifive_serial_port. yes queen, that's the port object, she's the main character here 👑

---

💖 DESCRIPTION 💖

so what this does: it disables interrupt generation when the transmit FIFO watermark is reached, on the UART that ssp refers to. no more "hey bestie the FIFO hit the watermark" interrupts from this port — we're silencing that notification, periodt. 🔇✨

think of it as putting your notifications on do-not-disturb for one specific thing. iconic behavior tbh 🫶

---

🔥 SEE ALSO 🔥

the whole friend group, no cap — go read these too:

• Kernel file ./drivers/tty/serial/sifive.c and 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_rxwm(9)
• __ssp_receive_char(9)
• __ssp_receive_chars(9)
• __ssp_update_div(9)
• __ssp_update_baud_rate(9)
• __ssp_set_stop_bits(9)
• __ssp_wait_for_xmitr(9)
• sifive_serial_clk_notifier(9)

---

💀 reminder: this is the disable one. if you actually WANT the watermark interrupt, you want __ssp_enable_txwm(9) — please don't mix them up bestie, i'm begging 🙈

---

okay that's the page!! she lives in ./drivers/tty/serial, she's from October 2026, and yes the footer still says __ssp_disable_txwm(9) because we stay on brand 💜🌈⭐

go off, kernel dev 🧚💖