diff options
| author | Lu Baolu <baolu.lu@linux.intel.com> | 2015-11-14 16:26:33 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2015-12-01 14:58:18 -0800 |
| commit | 513072d90a8dfe4bf83e1f81810de605eb5d7c3b (patch) | |
| tree | 101e668a61262a515b2ab8124f2d9ba568df7432 /drivers/usb/core/hub.c | |
| parent | bf5ce5bf3cc7136fd7fe5e8999a580bc93a9c8f6 (diff) | |
usb: core: lpm: add sysfs node for usb3 lpm permit
USB3 LPM is default on in Linux kernel if both xHCI host controller
and the USB devices declare to be LPM-capable. Unfortunately, some
devices are known to work well with LPM disabled, but to be broken
if LPM is enabled, although it declares the LPM capability. Users
won't be able to use this kind of devices, until someone puts them
in the kernel blacklist and gets the kernel upgraded.
This patch adds a sysfs node to permit or forbit USB3 LPM U1 or U2
entry for a port. The settings apply to both before and after device
enumeration. Supported values are "0" - neither u1 nor u2 permitted,
"u1" - only u1 is permitted, "u2" - only u2 is permitted, "u1_u2" -
both u1 and u2 are permitted. With this interface, users can use an
LPM-unfriendly USB device on a released Linux kernel.
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Zhuang Jin Can <jin.can.zhuang@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/usb/core/hub.c')
| -rw-r--r-- | drivers/usb/core/hub.c | 15 |
1 files changed, 13 insertions, 2 deletions
diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c index 59f998e60030..db7683e2d34c 100644 --- a/drivers/usb/core/hub.c +++ b/drivers/usb/core/hub.c @@ -4020,6 +4020,8 @@ EXPORT_SYMBOL_GPL(usb_unlocked_disable_lpm); void usb_enable_lpm(struct usb_device *udev) { struct usb_hcd *hcd; + struct usb_hub *hub; + struct usb_port *port_dev; if (!udev || !udev->parent || udev->speed != USB_SPEED_SUPER || @@ -4039,8 +4041,17 @@ void usb_enable_lpm(struct usb_device *udev) if (udev->lpm_disable_count > 0) return; - usb_enable_link_state(hcd, udev, USB3_LPM_U1); - usb_enable_link_state(hcd, udev, USB3_LPM_U2); + hub = usb_hub_to_struct_hub(udev->parent); + if (!hub) + return; + + port_dev = hub->ports[udev->portnum - 1]; + + if (port_dev->usb3_lpm_u1_permit) + usb_enable_link_state(hcd, udev, USB3_LPM_U1); + + if (port_dev->usb3_lpm_u2_permit) + usb_enable_link_state(hcd, udev, USB3_LPM_U2); } EXPORT_SYMBOL_GPL(usb_enable_lpm); |