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authorLu Baolu <baolu.lu@linux.intel.com>2015-11-14 11:26:33 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2015-12-02 01:58:18 +0300
commit513072d90a8dfe4bf83e1f81810de605eb5d7c3b (patch)
tree101e668a61262a515b2ab8124f2d9ba568df7432 /drivers/usb/core/hub.h
parentbf5ce5bf3cc7136fd7fe5e8999a580bc93a9c8f6 (diff)
downloadlinux-513072d90a8dfe4bf83e1f81810de605eb5d7c3b.tar.xz
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.h')
-rw-r--r--drivers/usb/core/hub.h5
1 files changed, 4 insertions, 1 deletions
diff --git a/drivers/usb/core/hub.h b/drivers/usb/core/hub.h
index 688817fb3246..45d070dd1d03 100644
--- a/drivers/usb/core/hub.h
+++ b/drivers/usb/core/hub.h
@@ -92,6 +92,8 @@ struct usb_hub {
* @status_lock: synchronize port_event() vs usb_port_{suspend|resume}
* @portnum: port index num based one
* @is_superspeed cache super-speed status
+ * @usb3_lpm_u1_permit: whether USB3 U1 LPM is permitted.
+ * @usb3_lpm_u2_permit: whether USB3 U2 LPM is permitted.
*/
struct usb_port {
struct usb_device *child;
@@ -104,6 +106,8 @@ struct usb_port {
struct mutex status_lock;
u8 portnum;
unsigned int is_superspeed:1;
+ unsigned int usb3_lpm_u1_permit:1;
+ unsigned int usb3_lpm_u2_permit:1;
};
#define to_usb_port(_dev) \
@@ -155,4 +159,3 @@ static inline int hub_port_debounce_be_stable(struct usb_hub *hub,
{
return hub_port_debounce(hub, port1, false);
}
-