feat: EP0 mouse/kbd polling, CC=12 investigation (Parallels xHCI)#239
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feat: EP0 mouse/kbd polling, CC=12 investigation (Parallels xHCI)#239
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Systematic investigation of CC=12 (Endpoint Not Enabled) on Parallels ARM64 virtual xHCI interrupt endpoints, with working EP0 GET_REPORT polling for both keyboard and mouse. ## Findings CC=12 on interrupt IN is a fundamental Parallels virtual xHC limitation: - Parallels proactively generates CC=12 Transfer Events after re-ConfigureEndpoint (before any TRBs are queued), signaling that interrupt IN transfers are not supported - This persists regardless of command sequence: BSR=0/1, bandwidth dance enabled/disabled, BEI flag, matching Linux byte-for-byte - EP0 control transfers work reliably; interrupt IN never completes - Linux keyboard/mouse works via Parallels Tools injection, not xHCI interrupt IN (Linux ftrace shows no interrupt TRB completions in trace) ## Working solution: EP0 GET_REPORT polling Both keyboard and mouse input work via EP0 GET_REPORT control transfers at 4 Hz (limited by Parallels virtual USB device timing, not our polling interval): - gr=N gk=N mr=N mk=N with ge=me=0 (zero errors) verified in testing - Ring recycling (StopEndpoint + SetTRDequeuePointer) for EP0 rings since Parallels does not follow Link TRBs on transfer rings ## Changes xhci.rs: - Mouse EP0 GET_REPORT polling: SET_PROTOCOL(boot) during init, then 4 Hz boot-protocol GET_REPORT via EP0 with ring recycling - EP0 ring recycling for keyboard (every ~84 polls) and mouse - Bandwidth dance (SKIP_BW_DANCE=false): matches Linux's xhci_check_bandwidth() sequence with 3x ConfigureEndpoint + 2x StopRing per slot — confirmed matching Linux ftrace byte-for-byte - BSR=0 confirmed correct (BSR=1 causes CC=19 Context State Error) - Added EP0_MOUSE_POLL_STATE, MOUSE_CTRL_DATA_BUF, queue_ep0_mouse_get_report() - Diagnostics: DIAG_DOORBELL_EP_STATE, DMA buffer address logging, endpoint state read after SET_CONFIG and at doorbell time - Polling interval: % 10 (20 Hz attempt; bottleneck is Parallels ~4 Hz) timer_interrupt.rs: - Heartbeat counters: mr= mk= me= for mouse EP0 polling status Co-Authored-By: Ryan Breen <ryan@ryanbreen.com> Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
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Summary
Changes
kernel/src/drivers/usb/xhci.rsSET_PROTOCOL(boot)during device init, then 4 Hz GET_REPORT via EP0 control pipe with ring recyclingSKIP_BW_DANCE=false): matches Linux'sxhci_check_bandwidth()with 3× ConfigureEndpoint + 2× StopRing per slotDIAG_DOORBELL_EP_STATE, DMA buffer address logging, endpoint state diagnostics% 10(20 Hz attempt; bottleneck is Parallels' ~250ms USB device timing, effective rate stays 4 Hz)kernel/src/arch_impl/aarch64/timer_interrupt.rsmr= mk= me=counters for mouse EP0 polling statusTest plan
gr=N gk=N ge=0sustained at 4 Hz with zero errorsmr=N mk=N me=0sustained at 4 Hz with zero errors🤖 Generated with Claude Code