On Thu, Aug 29, 2013 at 02:58:25PM -0400, Alan Stern wrote: > On Thu, 29 Aug 2013, Sarah Sharp wrote: > > > On Thu, Aug 29, 2013 at 10:06:16AM -0700, Greg Kroah-Hartman wrote: > > > Hi Sarah, > > > > > > I'm getting the following warnings from the 3.10.9 kernel all the time > > > when I unplug a USB 3 storage device from my laptop: > > > [203282.987687] usb 4-1: USB disconnect, device number 21 > > > [203282.992904] usb 4-1: Set SEL for device-initiated U1 failed. > > > [203282.992909] usb 4-1: Set SEL for device-initiated U2 failed. > > > > > > What can a "normal" user do with these "failed" messages? If nothing, > > > shouldn't we just turn them into debug messages instead? > > > > Yes, those messages should probably be toned down to debug level instead > > of warning level. If a device doesn't respond to the Set SEL request > > when USB 3.0 LPM is enabled, the user has a buggy device. Of course, I > > doubt anyone is going to return a drive based on those messages. > > > > That error message happens because the USB core is attempting to disable > > LPM for a disconnected device. The control transfer to set SEL fails, > > resulting in those messages. The xHCI driver still needs to disable the > > U1 and U2 timeouts for the port, so the core still needs to call into > > usb_set_lpm_timeout. However, we could skip the control transfer to the > > device. > > > > The problem is that the USB core doesn't mark the device as DISCONNECTED > > until after it attempts to disable LPM. > > Are you certain? Look at the order of the lines in the log above. Hmm, I'll have to look at the code more closely then. Sarah Sharp -- 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
