Re:I tested every IP KVM in my Homelab
by gregsadetsky on Friday June 05, 2026 @05:00PM
(#48418210)
TLDR - GLKVM's kernel emits a trailing 0-byte DATA packet (ZLP) (which PiKVM does not)
Supposedly, this is due to the `req->zero = ((count % maxpacket) == 0)` line in the kernel's f_hid.c - which, for 8-byte HID keyboard reports, makes it append a trailer packet. Strict BIOS HID stacks treat this 0-byte packet as malformed and beep.
Re:I tested every IP KVM in my Homelab
by JdeBP on Friday June 05, 2026 @07:51PM
(#48419889)
Interesting. My first thought is wondering whether the keyboard HID is adding report IDs to its input reports, because it isn't in boot mode or something. That would have that effect.
Supposedly, this is due to the `req->zero = ((count % maxpacket) == 0)` line in the kernel's f_hid.c - which, for 8-byte HID keyboard reports, makes it append a trailer packet. Strict BIOS HID stacks treat this 0-byte packet as malformed and beep.