A timeout occurred while waiting for the EHCI host controller Asynchronous Schedule to transition to the enabled state.

The source of problem is USB having a shortcoming in mA's of power being supplied to the root USB hub, more about my research to this point; (wifi USB sticks may demand much power in heavy use scenarios, therefore they turn out to cause or endure this issue logically for that reason.. but it shouldnt happen, 5GHz networking may play a role in increased power demand, issue may arise when a faulty USB hub cannot supply power to it) READ BELOW instead of this low words explanation; ;

It happened to me today on Windows 10, this error the doorbell thing, combined with also ''A timeout occurred while waiting for the EHCI host controller Asynchronous Schedule to transition to the enabled state.''

So what happened today, likely the source of this problem popping up:

• I reset the USB hub in Device manager. Not to solve anything, just out of routine, that hub had my Wifi usb adapter connected.

I went to Device manager > Universal Serial Bus-controllers > one of the ''USB root hub'' device entries (with my Wifi adapter listed in On/Off) and then in USB root hub device info, > Advanced, and the Reset hub button from there.

Once again, I had no issues until doing that for no obvious cause. I didn't restart my PC and just went on gaming, probably causing the earlier named heavy load on that USB port through the Wifi USB. So the problem was because after I reset/re-configure a root hub in device manager, I failed to restart my PC, which is asking for problems like this after you do something like that. After restarting I didn't see the issue again.

This may be useful information as it's yet another underlying problem to cause this, exposed. So the USB controllers and stuff like that *can* cause this error and USB devices cutting off suddenly.

It tells this is related, so anyone having this issue may try things like resetting the USB root hub devices under said category in Device manager. Maybe you'll strike the underlying problem with that..

Also this stuff being related reveals more about the structure; it seems USB power (in mA) is related, so if you persistently have this problem it can be A) your motherboard failing to supply enough power to USB ports/hub (like under heavy load, an device asking more and more power) or B) an USB device entering suspended or sleep mode for any reason, intended or not (so the error may appear in Event viewer without clear problem, it may just be a sign of your enabled power saving mode for unused devices). If it's the mobo failing to deliver sufficient power, check the BIOS settings, or return it under warranty because USB ports should be able to supply to their specification.

That last column is also the explanation for why some users fix it by putting their Wifi adapter to 2.4 GHz instead of 5GHz: the latter can demand more power as obviously it's a newer and heavier technology. Your wifi usb or wifi network card just consumes less power on 2.4 GHz mode. But, your motherboard should be able to supply the port it's in with enough power. If it isn't, your motherboard has a shortcoming and doesnt power the USB to its official specification for any technical cause, or the USB device isnt conform. Just saying this scenario shouldnt happen. Maybe its a chinese Wifi usb stick that isn't conform the standard for power consumption, who knows.

Also when one of the USB devices fail like that, ^, it seems to crash the USB root hub and several USB devices under the same root hub (more than 1 port) can fail, so USB devices interrupting can happen after it.

With this knownledge, you'd say if you have USB 3.0 ports, these might be able to supply more power. Anyone with issues could try plugging the device likely to cause the problem, in any free USB 3.0 port, even if that USB device doesn't need/support 3.0.

The ''device likely to deliver'' that heavy load scenario, is an USB Wifi adapter with probably 5Ghz network connection; this seems to cross the line of what a certain USB power is able to deliver in mA's of port power. That makes sense, because it could be downloading something and heavily using its 80Mhz band (where 2.4GHz has a 20MHz band).

I must admit that USB standard designers should take a read over this stuff as a power shortcoming shouldn't be possible in any scenario, especially not leading to the failure of a whole USB root hub with many devices disabling themselves!

To come back on the situation letting me link all this info into a mechanism.. my case may have happened simply because software incorrectly calculated how much mA in power to feed the USB ports, as I made changes to that (through resetting a hub in device manager as explained before). It however allowed correlating to the underlying cause mechanisms.

The source of problem is USB having a shortcoming in mA's of power being supplied to the root USB hub, more about my research to this point; (wifi USB sticks may demand much power in heavy use scenarios, therefore they turn out to cause or endure this issue logically for that reason.. but it shouldnt happen, 5GHz networking may play a role in increased power demand, issue may arise when a faulty USB hub cannot supply power to it) READ BELOW instead of this low words explanation; ;

It happened to me today on Windows 10, this error the doorbell thing, combined with also ''A timeout occurred while waiting for the EHCI host controller Asynchronous Schedule to transition to the enabled state.''

So what happened today, likely the source of this problem popping up:

• I reset the USB hub in Device manager. Not to solve anything, just out of routine, that hub had my Wifi usb adapter connected.

I went to Device manager > Universal Serial Bus-controllers > one of the ''USB root hub'' device entries (with my Wifi adapter listed in On/Off) and then in USB root hub device info, > Advanced, and the Reset hub button from there.

Once again, I had no issues until doing that for no obvious cause. I didn't restart my PC and just went on gaming, probably causing the earlier named heavy load on that USB port through the Wifi USB. So the problem was because after I reset/re-configure a root hub in device manager, I failed to restart my PC, which is asking for problems like this after you do something like that. After restarting I didn't see the issue again.

This may be useful information as it's yet another underlying problem to cause this, exposed. So the USB controllers and stuff like that *can* cause this error and USB devices cutting off suddenly.

It tells this is related, so anyone having this issue may try things like resetting the USB root hub devices under said category in Device manager. Maybe you'll strike the underlying problem with that..

Also this stuff being related reveals more about the structure; it seems USB power (in mA) is related, so if you persistently have this problem it can be A) your motherboard failing to supply enough power to USB ports/hub (like under heavy load, an device asking more and more power) or B) an USB device entering suspended or sleep mode for any reason, intended or not (so the error may appear in Event viewer without clear problem, it may just be a sign of your enabled power saving mode for unused devices). If it's the mobo failing to deliver sufficient power, check the BIOS settings, or return it under warranty because USB ports should be able to supply to their specification.

That last column is also the explanation for why some users fix it by putting their Wifi adapter to 2.4 GHz instead of 5GHz: the latter can demand more power as obviously it's a newer and heavier technology. Your wifi usb or wifi network card just consumes less power on 2.4 GHz mode. But, your motherboard should be able to supply the port it's in with enough power. If it isn't, your motherboard has a shortcoming and doesnt power the USB to its official specification for any technical cause, or the USB device isnt conform. Just saying this scenario shouldnt happen. Maybe its a chinese Wifi usb stick that isn't conform the standard for power consumption, who knows.

Also when one of the USB devices fail like that, ^, it seems to crash the USB root hub and several USB devices under the same root hub (more than 1 port) can fail, so USB devices interrupting can happen after it.

With this knownledge, you'd say if you have USB 3.0 ports, these might be able to supply more power. Anyone with issues could try plugging the device likely to cause the problem, in any free USB 3.0 port, even if that USB device doesn't need/support 3.0.

The ''device likely to deliver'' that heavy load scenario, is an USB Wifi adapter with probably 5Ghz network connection; this seems to cross the line of what a certain USB power is able to deliver in mA's of port power. That makes sense, because it could be downloading something and heavily using its 80Mhz band (where 2.4GHz has a 20MHz band).

I must admit that USB standard designers should take a read over this stuff as a power shortcoming shouldn't be possible in any scenario, especially not leading to the failure of a whole USB root hub with many devices disabling themselves!

To come back on the situation letting me link all this info into a mechanism.. my case may have happened simply because software incorrectly calculated how much mA in power to feed the USB ports, as I made changes to that (through resetting a hub in device manager as explained before). It however allowed correlating to the underlying cause mechanisms.

Just an update for anyone that finds this thread from Google:

The problem still exists on Windows 8.1 Update 2, at least with my TP-Link WN722N. My motherboard is the MSI 990FXA-GD65 v1.

Last moment's edit: I just noticed that TP-Link has issued a new driver TL-WN722N_V1_140918. I will try it out and report back if it fixes anything.

Edit 2: Yup, the problem is still there. Two years and a solution that works still hasn't been found. Get it together Microsoft/AMD/MSI/TP-Link/whoever this concerns. I pray that the bug is not there when Windows 10 launches.... Turns out I had downloaded the driver for TL-WN721N, oops.

Edit 3: After installing the proper driver, when torrenting, sometimes the download speed falls to 0 for a few moments and then goes back up, without disconnections. It's a first step in the right direction I guess.