When setting usb port's acpi power resource, there will be some xhci hub requests.
This will cause dead lock since xhci->lock has been held before setting acpi power
resource in the xhci_hub_control(). The usb_acpi_power_manageable() function might
fall into sleep so release xhci->lock before invoking it.
Signed-off-by: Lan Tianyu <tianyu.lan@xxxxxxxxx>
---
Change since v1:
release xhci->lock before invoking usb_acpi_power_manageable().
drivers/usb/host/xhci-hub.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/drivers/usb/host/xhci-hub.c b/drivers/usb/host/xhci-hub.c
index aa90ad4..65d416c 100644
--- a/drivers/usb/host/xhci-hub.c
+++ b/drivers/usb/host/xhci-hub.c
@@ -809,11 +809,13 @@ int xhci_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue,
temp = xhci_readl(xhci, port_array[wIndex]);
xhci_dbg(xhci, "set port power, actual port %d status = 0x%x\n", wIndex, temp);
+ spin_unlock_irqrestore(&xhci->lock, flags);
temp = usb_acpi_power_manageable(hcd->self.root_hub,
wIndex);
if (temp)
usb_acpi_set_power_state(hcd->self.root_hub,
wIndex, true);
+ spin_lock_irqsave(&xhci->lock, flags);
break;
case USB_PORT_FEAT_RESET:
temp = (temp | PORT_RESET);
@@ -917,11 +919,13 @@ int xhci_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue,
xhci_writel(xhci, temp & ~PORT_POWER,
port_array[wIndex]);
+ spin_unlock_irqrestore(&xhci->lock, flags);
temp = usb_acpi_power_manageable(hcd->self.root_hub,
wIndex);
if (temp)
usb_acpi_set_power_state(hcd->self.root_hub,
wIndex, false);
+ spin_lock_irqsave(&xhci->lock, flags);
break;
default:
goto error;
--
1.7.9.5
--
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