From: Thang Nguyen <tqngu...@apm.com>

As per USB 2.0 link power management addendum ECN, table 1-2, page 4,
device or host initiated via resume signaling; device-initiated resumes
can be optionally enabled/disabled by software. This patch adds support
to control enabling the USB2 RWE feature via DT/ACPI attribute.

Signed-off-by: Vu Nguyen <vngu...@apm.com>
Signed-off-by: Thang Nguyen <tqngu...@apm.com>
---
 Documentation/devicetree/bindings/usb/usb-xhci.txt | 1 +
 drivers/usb/host/xhci-plat.c                       | 3 +++
 drivers/usb/host/xhci.c                            | 5 ++++-
 drivers/usb/host/xhci.h                            | 1 +
 4 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/Documentation/devicetree/bindings/usb/usb-xhci.txt 
b/Documentation/devicetree/bindings/usb/usb-xhci.txt
index 966885c..9b4cd14 100644
--- a/Documentation/devicetree/bindings/usb/usb-xhci.txt
+++ b/Documentation/devicetree/bindings/usb/usb-xhci.txt
@@ -25,6 +25,7 @@ Required properties:
 
 Optional properties:
   - clocks: reference to a clock
+  - usb2-rwe-disable: disable USB2 LPM Remote Wakeup capable
   - usb3-lpm-capable: determines if platform is USB3 LPM capable
 
 Example:
diff --git a/drivers/usb/host/xhci-plat.c b/drivers/usb/host/xhci-plat.c
index ed56bf9..15c540d 100644
--- a/drivers/usb/host/xhci-plat.c
+++ b/drivers/usb/host/xhci-plat.c
@@ -220,6 +220,9 @@ static int xhci_plat_probe(struct platform_device *pdev)
                goto disable_clk;
        }
 
+       if (device_property_read_bool(&pdev->dev, "usb2-rwe-disable"))
+               xhci->quirks |= XHCI_RWE_DISABLE;
+
        if (device_property_read_bool(&pdev->dev, "usb3-lpm-capable"))
                xhci->quirks |= XHCI_LPM_SUPPORT;
 
diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
index 1a4ca02..f804868 100644
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -4183,7 +4183,10 @@ int xhci_set_usb2_hardware_lpm(struct usb_hcd *hcd,
                }
 
                pm_val &= ~PORT_HIRD_MASK;
-               pm_val |= PORT_HIRD(hird) | PORT_RWE | PORT_L1DS(udev->slot_id);
+               if ((xhci->quirks & XHCI_RWE_DISABLE) && (xhci->hci_version <= 
0x100))
+                       pm_val |= PORT_HIRD(hird) | PORT_L1DS(udev->slot_id);
+               else
+                       pm_val |= PORT_HIRD(hird) | PORT_RWE | 
PORT_L1DS(udev->slot_id);
                writel(pm_val, pm_addr);
                pm_val = readl(pm_addr);
                pm_val |= PORT_HLE;
diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h
index f945380..2b9bc33 100644
--- a/drivers/usb/host/xhci.h
+++ b/drivers/usb/host/xhci.h
@@ -1656,6 +1656,7 @@ struct xhci_hcd {
 #define XHCI_SSIC_PORT_UNUSED  (1 << 22)
 #define XHCI_NO_64BIT_SUPPORT  (1 << 23)
 #define XHCI_MISSING_CAS       (1 << 24)
+#define XHCI_RWE_DISABLE       (1 << 25)
        unsigned int            num_active_eps;
        unsigned int            limit_active_eps;
        /* There are two roothubs to keep track of bus suspend info for */
-- 
2.7.4

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