Gamepad companion compatibility drivers#
Gamepad companion compatibility driver#
Gamepad companion compatibility full#
Gamepad companion compatibility windows#

Gamepad companion compatibility windows#

To help enforce our design guidelines even further we have introduced a logo requirement which we believe will lead the emerging USB 3 ecosystem in the right direction and prevent systems with companion controllers appearing on the market.Īs of December 1, 2010, a new Windows Logo requirement will be in effect to ensure that the port routing is done correctly:

Gamepad companion compatibility driver#

Since the two parts of the hubs will be enumerated by different controllers running different driver stacks, there is no ability for sharing the information and coordination of status.

Gamepad companion compatibility drivers#

Often controller drivers need to coordinate between the two chipsets of the hub for things like overcurrent recovery, port power control, port indicators, etc. These two pieces of IP enumerate independently on the bus, but they are not truly independent as they share resources such as port power and indicators. A single USB 3 hub contains both 3.0 and 2.0 IP to enable connectivity to USB 3 and legacy devices. Having more controllers in the system impacts performance (boot, suspend, resume, shutdown), power consumption (the old controllers are notoriously bad on platform power), etc.Ĥ.

This quick speed switch is likely to result in hitting this situation, which will result in significant user experience and stability issues.ģ. This is particularly bad for USB 3.0 since users have seen where due to mechanical design issues with the connectors, some devices may enumerate over USB 2.0 first and then jump to USB 3.0 later. If a device changes speeds, there would be no synchronization between the drivers for the different controllers, possibly resulting in multiple device instances with identical instance id being reported to PnP which may result in a bugcheck, enumeration failure, or other issue. This may become worse if one of the driver stacks is disabled (maybe due to updating the driver).Ģ. Either controller could be started before the other, potentially leading to devices connecting to the wrong host. No load order guarantees or power up ordering guarantees. After a decade of dealing with companion controller issues and overly complicated designs, the Windows USB team have come to a conclusion thatĬompanion controllers introduce more problems than they solve and tend to lead to poor user experience.Īs such we urge our partners to avoid wiring XHCI and EHCI to the same physical connectors when designing their USB 3 solutions due to the following reasons:ġ. Many vendors chose the companion controller route. To offer compatibility in EHCI there were two options: include a USB 2.0 hub for rate matching or add companion controllers so that EHCI/OHCI/UHCI controllers were wired to the same physical USB 2 ports.

Gamepad companion compatibility full#

In the past Microsoft supported vendors that used companion controllers when USB 2 specification first came out so that all systems can work with USB 1.0, 1.1 and 2.0 seamlessly.Įven though the USB 2 spec actually included support for full and low speed devices, the EHCI spec did not provide compatibility with full/low speed devices. Here is what a high level companion controller design would look like for EHCI and XHCI:Ĭompanion controllers may seem appealing as mitigation to compatibility concerns with older devices. If you work with firmware or software, like devices and drivers, you are welcome to continue reading however, you might not find the content as applicable to your designs.Ĭompanion controller is defined as multiple USB host controllers (XHCI/EHCI/OHCI/UHCI) that are wired to the same physical connector such that a device, depending on some characteristic like speed, will be connected to a different controller even when plugged into the same connector. This content is targeted primarily towards hardware designers and chipset manufacturers. In today’s blog post, I’ll be covering companion controllers. My name is Jane Lawrence and I am a program manager for USB Compatibility and USB Windows Logo Kit.