mlx4_ACCESS_REG(9)

💖 mlx4_ACCESS_REG(9) 💖

okay so bestie, welcome to the Kernel API Manual — this is the page for mlx4_ACCESS_REG, aka the generic access reg command. she's short, she's sweet, she's literally the plug for talking to your ConnectX registers. let's get into it 🎀

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✨ NAME ✨

mlx4_ACCESS_REG — the generic access reg command, no cap. that's her whole job. 💅

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🦋 SYNOPSIS 🦋

int mlx4_ACCESS_REG (struct mlx4_dev *dev , u16 reg_id , enum
mlx4_access_reg_method method , u16 reg_len , void *reg_data );

like… look at that signature. she's giving main character energy fr fr 🔥

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🌸 ARGUMENTS 🌸

• dev — a mlx4_dev. that's your device, bestie, the whole vibe check happens here 🫶
• reg_id — the register ID you wanna access. which register? this one, babes ✨
• method — the access method, Read or Write. pick a lane 💅
• reg_len — the register length to Read/Write, in bytes. yes, bytes. don't come at me with bits 🙈
• reg_data — the reg_data pointer to Read/Write From/To. it's the data going in or coming out, depending on what you're doing 😭

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⭐ DESCRIPTION ⭐

so what does she actually do? she runs the Access ConnectX registers FW command 👑 that's the whole serve.

she returns 0 on success — and on that success she copies the outbox mlx4_access_reg data field into reg_data. cute, right? 💖

or… she returns a negative error code. 😭 not the vibe, but at least she tells you.

ngl bestie, if you get a negative number back, that's your sign something went sideways — handle it, don't ignore it 🙏

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🌈 SEE ALSO 🌈

• Kernel file ./drivers/net/ethernet/mellanox/mlx4/fw.c — go read the source, iykyk 📖
• mlx4_ACCESS_PTYS_REG(9) — her sibling, go say hi 💜

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aaaand that's the page!! 🧚 this was mlx4_ACCESS_REG(9) from the Kernel API Manual, straight out of ./drivers/net/ethernet/mellano..., dated October 2026. slay, you made it to the end, periodt 💅✨🍓