Possible patch for putting NPU into right state

gistfile1.txt

From 911645703dddcf2c0911d73f1791927cfd4d888e Mon Sep 17 00:00:00 2001
From: Mario Limonciello <mario.limonciello@amd.com>
Date: Thu, 9 May 2024 19:29:20 -0500
Subject: [PATCH] x86/pci: Put NPU into D3 after resume if it's not bound to a
 driver

Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
---
 arch/x86/pci/fixup.c | 26 ++++++++++++++++++++++++++
 1 file changed, 26 insertions(+)

diff --git a/arch/x86/pci/fixup.c b/arch/x86/pci/fixup.c
index ff1fbc39086d..bd6a8d213a46 100644
--- a/arch/x86/pci/fixup.c
+++ b/arch/x86/pci/fixup.c
@@ -988,6 +988,25 @@ static void amd_rp_pme_suspend(struct pci_dev *dev)
 	dev_info_once(&rp->dev, "quirk: disabling D3cold for suspend\n");
 }
 
+static void amd_rp_put_child_d3(int device)
+{
+	struct pci_dev *child;
+
+	child = pci_get_device(PCI_VENDOR_ID_AMD, device, NULL);
+	if (child) {
+		if (!device_trylock(&child->dev)) {
+			pci_dev_put(child);
+			return;
+		}
+		if (!child->dev.driver) {
+			dev_info(&child->dev, "Setting to D3hot\n");
+			pci_set_power_state(child, PCI_D3hot);
+		}
+		device_unlock(&child->dev);
+		pci_dev_put(child);
+	}
+}
+
 static void amd_rp_pme_resume(struct pci_dev *dev)
 {
 	struct pci_dev *rp;
@@ -999,6 +1018,13 @@ static void amd_rp_pme_resume(struct pci_dev *dev)
 
 	pci_read_config_word(rp, rp->pm_cap + PCI_PM_PMC, &pmc);
 	rp->pme_support = FIELD_GET(PCI_PM_CAP_PME_MASK, pmc);
+
+	/*
+	 * Make sure that any if NPU doesn't have a driver it is put back into D3
+	 * after the quirk is done
+	 */
+	amd_rp_put_child_d3(0x1502);
+	amd_rp_put_child_d3(0x14ec);
 }
 /* Rembrandt (yellow_carp) */
 DECLARE_PCI_FIXUP_SUSPEND(PCI_VENDOR_ID_AMD, 0x162e, amd_rp_pme_suspend);
-- 
2.43.0