dev_pm_get_subsys_data(9)

✨ dev_pm_get_subsys_data(9) ✨

okay bestie, buckle up, we're in the Kernel API Manual today and this one is a little refcount baddie 💅

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🎀 NAME 🎀

dev_pm_get_subsys_data — creates the power.subsys_data for a device, or refcounts it if it's already there. literally that's her whole job 🫶

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🌸 SYNOPSIS 🌸

int dev_pm_get_subsys_data (struct device *dev );

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🦋 ARGUMENTS 🦋

• dev — the device you're handling. the main character of this function, no cap 💖

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✨ DESCRIPTION ✨

so here's the vibe check 👑

If power.subsys_data is NULL, this function points it at a brand new object. If it's not NULL, it just bumps that object's reference counter instead. either way she's making sure the thing exists and stays alive 🧚

Return value tea ☕:

• 0 — slay, it worked. either a new object got created or the refcount got increased.
• negative error code — not slay 😭 something went wrong.

ngl if you see a negative number come back, that's your sign to go handle it. don't just ignore it, bestie 💀

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🔥 SEE ALSO 🔥

Kernel file ./drivers/base/power/common.c + the whole friend group:

• dev_pm_put_subsys_data(9)
• dev_pm_domain_attach(9)
• dev_pm_domain_attach_by_id(9)
• dev_pm_domain_attach_by_name(9)
• dev_pm_domain_attach_list(9)
• devm_pm_domain_detach_list(9)
• devm_pm_domain_attach_list(9)
• dev_pm_domain_detach(9)
• dev_pm_domain_detach_list(9)
• dev_pm_domain_start(9)
• dev_pm_domain_set(9)
• dev_pm_domain_set_performance_state(9)

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and that's the whole page, bestie 🎀 this one lives under ./drivers/base/power and it's dated October 2026, filed under dev_pm_get_subsys_data(9) — go forth and refcount responsibly, ily 🌈💜