xe_sysctrl_send_command(9)

💌 xe_sysctrl_send_command(9) 💌

okay bestie, welcome to the Kernel API Manual — yes we're reading kernel docs together, this is our bonding era 🫶

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✨ NAME ✨

xe_sysctrl_send_command — literally just sending a mailbox command to the System Controller, that's the whole vibe 💅

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🌸 SYNOPSIS 🌸

int xe_sysctrl_send_command (struct xe_sysctrl *sc , struct
       xe_sysctrl_mailbox_command *cmd , size_t *rdata_len );

no cap, that's the exact signature, don't come for me about the line break, it's how the original rolls 😌

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🎀 ARGUMENTS 🎀

• sc — your System Controller instance, the main character of this whole operation 👑
• cmd — the command descriptor, and she's carrying the request header AND the payload buffers, highkey doing the most 👜
• rdata_len — a pointer where we store the actual response data length, so like... the receipts 📝

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🦋 DESCRIPTION 🦋

So here's what's tea: this function sends a mailbox command to the System Controller firmware using the System Controller mailbox, and then it waits for a response. That's it, that's the function. Patient queen behavior, honestly ⏳✨

The request payload gets provided via cmd->data_in and cmd->data_in_len. If a response is expected (iykyk), then cmd->data_out has to point to a buffer of size cmd->data_out_len supplied by the caller — so you gotta bring your own buffer, bestie, it's not gonna conjure one for you 🎁

On success, rdata_len gets updated with the number of valid response bytes returned by the firmware, bounded by cmd->data_out_len. So it'll never overflow your buffer, she's respectful like that 💖

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⭐ RETURN ⭐

0 on success, or a negative errno on failure. Simple. Iconic. Periodt 💀

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🔥 SEE ALSO 🔥

• Kernel file ./drivers/gpu/drm/xe/xe_sysctrl_mailbox.c — go read the source, it's giving lore 📖
• xe_sysctrl_create_command(9) — the prequel, watch it first 🎬

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ngl this one's short and sweet, so go forth and send those mailbox commands, bestie 🌈

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and that's the whole page!! brought to you by ./drivers/gpu/drm/xe, dated October 2026, page xe_sysctrl_send_command(9) — mwah, love u, bye 💜🧚‍♀️