Re: 0bda:b812 USB "3.0" WLAN devices only report a maximum of 480 Mbps

[Greg KH <gregkh@linuxfoundation.org>]

On Sun, Nov 05, 2023 at 01:49:09PM +0100, Fabian Melzow wrote:
> Am Sun, 5 Nov 2023 13:20:38 +0100
> schrieb Greg KH <gregkh@linuxfoundation.org>:
> 
> > On Sun, Nov 05, 2023 at 01:02:15PM +0100, Fabian Melzow wrote:
> > > These devices should report 5 Gbps for USB 3.0 in the Binary Object
> > > Store Descriptor, but don't do so.  
> > 
> > Why do you think these should report 5 Gbps?  If the device descriptor
> > does not show it, there's nothing that we can do about it in the
> > operating system, sorry.
> 
> Thanks. I don't look at the USB specification for USB >2.0, which
> was long times ago and then only for a user space program and thought
> that it at least theoretically could be possible to set the device
> speed at some kind of initialization.

There might be some vendor-specific way of doing this, and then the
device resets itself, but other than that, no, descriptors are a static
description of the device's capabilities.

> > > Maybe it is possible to add a software fix for this hardware
> > > problem, so I report it here.  
> > 
> > What exactly is the hardware problem?  What is not working "properly"
> > for them?
> 
> All 0bda:b812 USB-WLAN-devices seems to only operate at 480 Mbps,
> but have a WLAN-chip which supports 780 Mbps at maximum.

Are you sure that those devices really can run at 480 Mbps?  Perhaps the
chip can support higher, but the firmware on the device, and the other
stuff in the device does not?

thanks,

greg k-h