On Thu, 24 Jan 2013, Ming Lei wrote: > On Thu, Jan 24, 2013 at 12:08 AM, Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> wrote: > > > > Not increasing the delay explains why you got all those "suspend failed > > because a port is resuming" messages. > > Alan, looks the "suspend failed because a port is resuming" messages" > is nothing to do with the autosuspend delay, Not so. It's true that the message can be produced even when the delay is present, but if the delay is set to 30 ms then you will get no more than one message every 30 ms. By contrast, Norbert was getting about 8 messages per ms. > and increase the delay > doesn't make the messages disappear[1]. The message is produced because > port change event is missed while host is sending ports resuming signal. Yes, I know. > I have post one patch which may remove the message, see link[2]. I don't think sleeping is the right answer. For example, at the same time as the resume there could be a new device plugged in. What we really want to do is prevent the root hub from autosuspending while the resume signal is active. One possibility is to have the HCD call pm_runtime_get_noresume. Can you think of anything better? Alan Stern -- 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
