On Mon, Jun 25, 2012 at 03:39:59PM -0700, Sarah Sharp wrote: > USB 3.0 devices may optionally support a new feature called Latency > Tolerance Messaging. If both the xHCI host controller and the device > support LTM, it should be turned on in order to give the system hardware > a better clue about the latency tolerance values of its PCI devices. > > LTM is disabled by default on enumeration or after device reset. Once a > Set Feature request to enable LTM is received, the USB 3.0 device will > begin to send LTM updates as its buffers fill or empty, and it can > tolerate more or less latency. > > Make the USB core enable LTM after the device is reset. The USB 3.0 > spec, section C.4.2 says that LTM should be disabled just before the > device is placed into suspend. Then the device will send an updated LTM > notification, so that the system doesn't think it should remain in an > active state in order to satisfy the latency requirements of the > suspended device. > > Signed-off-by: Sarah Sharp <sarah.a.sharp@xxxxxxxxxxxxxxx> > --- > drivers/usb/core/hub.c | 66 +++++++++++++++++++++++++++++++++++++++++++++-- > 1 files changed, 63 insertions(+), 3 deletions(-) I know you added support for the parsing of the device descriptor in lsusb, but would it also be nice to add this to a sysfs file as well, for those programs that don't want to parse the bits in the descriptor (or don't know how to?) That's not saying there's anything wrong with this patch at all, but how about an add-on patch adding that? thanks, greg k-h -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
