From 581cc054804359b7b7c67d5723dfb3a2f3657957 Mon Sep 17 00:00:00 2001
From: jsg <jsg@openbsd.org>
Date: Sat, 17 Aug 2024 01:55:03 +0000
Subject: [PATCH] skip Controller Save State (CSS) and Controller Restore State
 (CRS) on AMD 17h/1xh xHCI

avoids problem with resume after CRS was introduced in xhci.c rev 1.133
uhub0: device problem, disabling port 2
uhub1: device problem, disabling port 1

reported by brynet@ and reproduced on t495, ok kettenis@
---
 sys/dev/pci/xhci_pci.c |  7 ++++++-
 sys/dev/usb/xhci.c     | 31 ++++++++++++++++---------------
 sys/dev/usb/xhcivar.h  |  5 ++++-
 3 files changed, 26 insertions(+), 17 deletions(-)

diff --git a/sys/dev/pci/xhci_pci.c b/sys/dev/pci/xhci_pci.c
index 5409588f39c..e906f16c88e 100644
--- a/sys/dev/pci/xhci_pci.c
+++ b/sys/dev/pci/xhci_pci.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: xhci_pci.c,v 1.13 2024/05/24 06:02:58 jsg Exp $ */
+/*	$OpenBSD: xhci_pci.c,v 1.14 2024/08/17 01:55:03 jsg Exp $ */
 
 /*
  * Copyright (c) 2001, 2002 The NetBSD Foundation, Inc.
@@ -151,6 +151,11 @@ xhci_pci_attach(struct device *parent, struct device *self, void *aux)
                     PCI_PRODUCT(pa->pa_id) == PCI_PRODUCT_FRESCO_FL1400)
 			pa->pa_flags &= ~PCI_FLAGS_MSI_ENABLED;
 		break;
+	case PCI_VENDOR_AMD:
+		if (PCI_PRODUCT(pa->pa_id) == PCI_PRODUCT_AMD_17_1X_XHCI_1 ||
+		    PCI_PRODUCT(pa->pa_id) == PCI_PRODUCT_AMD_17_1X_XHCI_2)
+			psc->sc.sc_flags |= XHCI_NOCSS;
+		break;
 	}
 
 	/* Map and establish the interrupt. */
diff --git a/sys/dev/usb/xhci.c b/sys/dev/usb/xhci.c
index 75792693b70..d7a1fc0c9f1 100644
--- a/sys/dev/usb/xhci.c
+++ b/sys/dev/usb/xhci.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: xhci.c,v 1.133 2024/08/15 17:17:05 kettenis Exp $ */
+/* $OpenBSD: xhci.c,v 1.134 2024/08/17 01:55:03 jsg Exp $ */
 
 /*
  * Copyright (c) 2014-2015 Martin Pieuchot
@@ -626,24 +626,25 @@ xhci_suspend(struct xhci_softc *sc)
 	 * will prevent the SoC from reaching its lowest idle state.
 	 * So save the state here.
 	 */
+	if ((sc->sc_flags & XHCI_NOCSS) == 0) {
+		XOWRITE4(sc, XHCI_USBCMD, XHCI_CMD_CSS); /* Save state */
+		hcr = XOREAD4(sc, XHCI_USBSTS);
+		for (i = 0; i < 100; i++) {
+			usb_delay_ms(&sc->sc_bus, 1);
+			hcr = XOREAD4(sc, XHCI_USBSTS) & XHCI_STS_SSS;
+			if (!hcr)
+				break;
+		}
 
-	XOWRITE4(sc, XHCI_USBCMD, XHCI_CMD_CSS); /* Save state */
-	hcr = XOREAD4(sc, XHCI_USBSTS);
-	for (i = 0; i < 100; i++) {
-		usb_delay_ms(&sc->sc_bus, 1);
-		hcr = XOREAD4(sc, XHCI_USBSTS) & XHCI_STS_SSS;
-		if (!hcr)
-			break;
-	}
+		if (hcr) {
+			printf("%s: save state timeout\n", DEVNAME(sc));
+			xhci_reset(sc);
+			return;
+		}
 
-	if (hcr) {
-		printf("%s: save state timeout\n", DEVNAME(sc));
-		xhci_reset(sc);
-		return;
+		sc->sc_saved_state = 1;
 	}
 
-	sc->sc_saved_state = 1;
-
 	/* Disable interrupts. */
 	XRWRITE4(sc, XHCI_IMOD(0), 0);
 	XRWRITE4(sc, XHCI_IMAN(0), 0);
diff --git a/sys/dev/usb/xhcivar.h b/sys/dev/usb/xhcivar.h
index cf1e86feb56..884cd5b732e 100644
--- a/sys/dev/usb/xhcivar.h
+++ b/sys/dev/usb/xhcivar.h
@@ -1,4 +1,4 @@
-/* $OpenBSD: xhcivar.h,v 1.15 2024/08/15 17:17:05 kettenis Exp $ */
+/* $OpenBSD: xhcivar.h,v 1.16 2024/08/17 01:55:03 jsg Exp $ */
 
 /*
  * Copyright (c) 2014 Martin Pieuchot
@@ -121,6 +121,9 @@ struct xhci_softc {
 
 	char			 sc_vendor[16];	/* Vendor string for root hub */
 	int			 sc_id_vendor;	/* Vendor ID for root hub */
+	
+	int			 sc_flags;
+#define XHCI_NOCSS		 0x01
 };
 
 int	xhci_init(struct xhci_softc *);
-- 
2.20.1