diff options
| author | Sarah Sharp <sarah.a.sharp@linux.intel.com> | 2012-02-20 20:31:26 +0400 |
|---|---|---|
| committer | Sarah Sharp <sarah.a.sharp@linux.intel.com> | 2012-05-19 02:41:54 +0400 |
| commit | d9b2099cd66de3164f6e17a5c0e3f14cce24a9a3 (patch) | |
| tree | 8e83a7b715f1ddbfbf9fb9130c2df4a1d073f180 /drivers/usb | |
| parent | 448b6eb1e04cddc418d4b780ae19ca8cdb42d110 (diff) | |
| download | linux-d9b2099cd66de3164f6e17a5c0e3f14cce24a9a3.tar.xz | |
USB: Refactor code to set LPM support flag.
Refactor the code that sets the usb_device flag to indicate the device
support link power management (lpm_capable). The current code sets
lpm_capable unconditionally if the USB devices have a USB 2.0 Extended
Capabilities Descriptor. USB 3.0 devices can also have that descriptor,
but the xHCI driver code that uses lpm_capable will not run the USB 2.0
LPM test for devices under the USB 3.0 roothub. Therefore, it's fine
only set lpm_capable for high speed devices in this refactoring.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Diffstat (limited to 'drivers/usb')
| -rw-r--r-- | drivers/usb/core/hub.c | 22 |
1 files changed, 17 insertions, 5 deletions
diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c index c8e0704c6e5d..100e08f8a027 100644 --- a/drivers/usb/core/hub.c +++ b/drivers/usb/core/hub.c @@ -177,6 +177,21 @@ static struct usb_hub *hdev_to_hub(struct usb_device *hdev) return usb_get_intfdata(hdev->actconfig->interface[0]); } +static int usb_device_supports_lpm(struct usb_device *udev) +{ + /* USB 2.1 (and greater) devices indicate LPM support through + * their USB 2.0 Extended Capabilities BOS descriptor. + */ + if (udev->speed == USB_SPEED_HIGH) { + if (udev->bos->ext_cap && + (USB_LPM_SUPPORT & + le32_to_cpu(udev->bos->ext_cap->bmAttributes))) + return 1; + return 0; + } + return 0; +} + /* USB 2.0 spec Section 11.24.4.5 */ static int get_hub_descriptor(struct usb_device *hdev, void *data) { @@ -3211,11 +3226,8 @@ hub_port_init (struct usb_hub *hub, struct usb_device *udev, int port1, if (udev->wusb == 0 && le16_to_cpu(udev->descriptor.bcdUSB) >= 0x0201) { retval = usb_get_bos_descriptor(udev); - if (!retval) { - if (udev->bos->ext_cap && (USB_LPM_SUPPORT & - le32_to_cpu(udev->bos->ext_cap->bmAttributes))) - udev->lpm_capable = 1; - } + if (!retval) + udev->lpm_capable = usb_device_supports_lpm(udev); } retval = 0; |