Re: [REGRESSION] CyberPower LE1000DG (0764:0501) USB HID regression on x86

On Sat, Aug 08, 2026 at 03:14:38PM -0400, Jamie Stephens wrote:
> I also completed the test with a separate PCIe USB controller based on
> the ASMedia ASM1042.
> 
> The UPS enumerates normally on the ASMedia controller and the kernel
> identifies it correctly as the CyberPower LE1000DG (0764:0501).
> However, on this controller the failure mode is different.
> 
> The device and HID descriptors are readable, but the 504-byte HID
> report descriptor is consistently unavailable. Ten consecutive runs
> of:
> 
>     lsusb -v -d 0764:0501
> 
> all showed:
> 
>     Report Descriptors:
>         ** UNAVAILABLE **
> 
> NUT behaves consistently with that result. usbhid-ups successfully
> opens the device and claims interface 0, but then fails while
> attempting to retrieve the HID report descriptor:
> 
>     Unable to get HID descriptor (Pipe error)
>     HID descriptor length 504
>     Unable to get Report descriptor: Resource temporarily unavailable
>     No matching HID UPS found
> 
> There are no USB disconnects or xHCI errors in dmesg. The device
> remains present and enumerated on the ASMedia controller.

What shows up in usbmon (or equivalently, Wireshark)?

Alan Stern