axis_fifo_read(9)

🌈 axis_fifo_read(9) 🌈

okay so bestie, this is the Kernel API Manual page for axis_fifo_read, and it's literally about reading a packet from the AXIS-FIFO character device. 💖

🌸 NAME 🌸

axis_fifo_read — read a packet from the AXIS-FIFO character device. periodt. ✨

✨ SYNOPSIS ✨

the signature is giving kernel-dev realness, no cap:

ssize_t axis_fifo_read (struct file *f , char __user *buf , size_t len ,
       loff_t *off );

🎀 ARGUMENTS 🎀

• f — the open file. like, the file is already open, bestie. 🫶
• buf — the user space buffer to read to. that's where the bytes go. 🍓
• len — the user space buffer length. how much room buf has. 💅
• off — the buffer offset. the offset vibe check. 🦋

💜 DESCRIPTION 💜

the device's documentation says we need to check the device's occupancy before reading the length register and then the data. 👑

and bestie, all these operations must be executed atomically, in order, and one after the other without missing any. no cap, no skipping, no missing steps. 😭🔥

🌟 RETURN 🌟

it returns the number of bytes read from the device, or a negative error code on failure. that's the return-value tea. 💀✨

🦋 SEE ALSO 🦋

• Kernel file: ./drivers/staging/axis-fifo/axis-fifo.c
• Also peep: axis_fifo_write(9)

okay bye bestie 💖 — from ./drivers/staging/axis-fifo, October 2026, page axis_fifo_read(9) 🎀💅