ufshcd_dme_c...e_power_mode(9)

📦 version 7.3.1, in nixpkgs unstable

💅💖 ufshcd_dme_change_power_mode — NAME

Okay so bestie, welcome to the Kernel API Manual (section 9, we're fancy here) 🎀 — this one is ufshcd_dme_change_power_mode, aka the UniPro DME Power Mode change sequence ✨. Like, it's the function that literally walks the UFS link into a whole new power mode. Main character energy fr fr. 👑

🦋 SYNOPSIS

int ufshcd_dme_change_power_mode (struct ufs_hba *hba , struct
ufs_pa_layer_attr *pwr_mode , enum ufshcd_pmc_policy pmc_policy );

🌸 ARGUMENTS

  • hba — the per-adapter instance, your one and only 💅
  • pwr_mode — a pointer to the target power mode (gear/lane) attributes, i.e. where we're headed 🦋
  • pmc_policy — the Power Mode change policy, the rules of the vibe check 👑

✨ DESCRIPTION ✨

So this function handles the low-level DME (Device Management Entity) configuration that's required to transition the UFS link over to a new power mode. It runs the steps, in order, no skipping (this is the whole itinerary bestie):

  1. Checks if the requested mode actually matches the current state. (Like, are we already there? 💀)
  2. Sets the M-PHY and UniPro attributes — including Gear (PA_RXGEAR/TXGEAR), Lanes, Termination, and HS Series (PA_HSSERIES). Obsessed with a good attribute set 🌈
  3. Configures the default UniPro timeout values (DL_FC0, etc.) — unless it's explicitly skipped via quirks, iykyk 🙈
  4. Triggers the actual hardware mode change via ufshcd_uic_change_pwr_mode. This is the moment. 🎬
  5. Updates the HBA's cached power information on success. Cache stays slay. 💖

🫶 RETURN

0 on success, non-zero error code on failure. That's it, that's the whole vibe check ⭐

👑 SEE ALSO

The whole ufshcd family reunion, no cap — and the kernel file ./drivers/ufs/core/ufshcd.c is where the magic lives:

Also worth knowing: this page lives under ./drivers/ufs/core and it's dated October 2026, and the man page itself is ufshcd_dme_c...e_power_mode(9) — yes the title got truncated, she's mysterious like that 💅

Okay that's the whole page bestie, go forth and change some power modes 💖✨🎀🦋🌸🫶

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