From 2a632815683d2d34df52b701a36fe5ac6654e719 Mon Sep 17 00:00:00 2001
From: Sandeep Singh <sandeep.singh@amd.com>
Date: Wed, 28 Oct 2020 22:31:23 +0200
Subject: [PATCH] usb: xhci: Workaround for S3 issue on AMD SNPS 3.0 xHC
Git-commit: 2a632815683d2d34df52b701a36fe5ac6654e719
References: git-fixes
Patch-mainline: v5.10-rc2

On some platform of AMD, S3 fails with HCE and SRE errors. To fix this,
need to disable a bit which is enable in sparse controller.

Cc: stable@vger.kernel.org #v4.19+
Signed-off-by: Sanket Goswami <Sanket.Goswami@amd.com>
Signed-off-by: Sandeep Singh <sandeep.singh@amd.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20201028203124.375344-3-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Oliver Neukum <oneukum@suse.com>
---
 drivers/usb/host/xhci-pci.c |   17 +++++++++++++++++
 drivers/usb/host/xhci.h     |    1 +
 2 files changed, 18 insertions(+)

--- a/drivers/usb/host/xhci-pci.c
+++ b/drivers/usb/host/xhci-pci.c
@@ -22,6 +22,8 @@
 #define SSIC_PORT_CFG2_OFFSET	0x30
 #define PROG_DONE		(1 << 30)
 #define SSIC_PORT_UNUSED	(1 << 31)
+#define SPARSE_DISABLE_BIT	17
+#define SPARSE_CNTL_ENABLE	0xC12C
 
 /* Device for a quirk */
 #define PCI_VENDOR_ID_FRESCO_LOGIC	0x1b73
@@ -151,6 +153,9 @@ static void xhci_pci_quirks(struct devic
 	    (pdev->device == 0x15e0 || pdev->device == 0x15e1))
 		xhci->quirks |= XHCI_SNPS_BROKEN_SUSPEND;
 
+	if (pdev->vendor == PCI_VENDOR_ID_AMD && pdev->device == 0x15e5)
+		xhci->quirks |= XHCI_DISABLE_SPARSE;
+
 	if (pdev->vendor == PCI_VENDOR_ID_AMD)
 		xhci->quirks |= XHCI_TRUST_TX_LENGTH;
 
@@ -480,6 +485,15 @@ static void xhci_pme_quirk(struct usb_hc
 	readl(reg);
 }
 
+static void xhci_sparse_control_quirk(struct usb_hcd *hcd)
+{
+	u32 reg;
+
+	reg = readl(hcd->regs + SPARSE_CNTL_ENABLE);
+	reg &= ~BIT(SPARSE_DISABLE_BIT);
+	writel(reg, hcd->regs + SPARSE_CNTL_ENABLE);
+}
+
 static int xhci_pci_suspend(struct usb_hcd *hcd, bool do_wakeup)
 {
 	struct xhci_hcd	*xhci = hcd_to_xhci(hcd);
@@ -499,6 +513,9 @@ static int xhci_pci_suspend(struct usb_h
 	if (xhci->quirks & XHCI_SSIC_PORT_UNUSED)
 		xhci_ssic_port_unused_quirk(hcd, true);
 
+	if (xhci->quirks & XHCI_DISABLE_SPARSE)
+		xhci_sparse_control_quirk(hcd);
+
 	ret = xhci_suspend(xhci, do_wakeup);
 	if (ret && (xhci->quirks & XHCI_SSIC_PORT_UNUSED))
 		xhci_ssic_port_unused_quirk(hcd, false);
--- a/drivers/usb/host/xhci.h
+++ b/drivers/usb/host/xhci.h
@@ -1876,6 +1876,7 @@ struct xhci_hcd {
 #define XHCI_RESET_PLL_ON_DISCONNECT	BIT_ULL(34)
 #define XHCI_SNPS_BROKEN_SUSPEND    BIT_ULL(35)
 #define XHCI_SKIP_PHY_INIT     BIT_ULL(37)
+#define XHCI_DISABLE_SPARSE	BIT_ULL(38)
 
 	unsigned int		num_active_eps;
 	unsigned int		limit_active_eps;