Cross-referenced with Linux 7.1 drivers/usb/storage/usb.c and SPC-3 §6.27.
Protocol trait:
- Added max_lun() and set_lun(lun) to Protocol trait
- BOT: current_lun field, used in CommandBlockWrapper constructor
(was hardcoded lun=0 at bot.rs:212)
- UAS: current_lun field, used in CommandIU.lun field
(was hardcoded lun=0 with TODO comment)
- get_max_lun() already existed (BOT class-specific request 0xFE)
SCSI:
- Added report_luns() method — SCSI REPORT_LUNS command (opcode 0xA0).
Returns Vec<u64> of 8-byte LUN addresses per SPC-3 format.
Handles big-endian LUN list length and per-entry parsing.
- Import opcodes::Opcode
main.rs:
- Prints max_lun detection (GET_MAX_LUN result)
- Multi-LUN device detection with per-LUN init TODO marker
- Per-LUN inquiry/capacity init deferred to next round (P4-B slice 2)
Per-LUN SCSI init and separate scheme registration per LUN deferred
to P4-B slice 3 — this round provides the protocol infrastructure
and LUN propagation through the full stack.
Infrastructure:
- XhciEndpCtlReq::Transfer gains stream_id: u16 field (serde default=0
for backward compatibility)
- scheme.rs execute_transfer: fixed hardcoded stream_id=1 ring lookup
to use caller-provided stream_id
- transfer() method gains stream_id parameter; all existing callers
pass 0 (non-stream endpoints)
- driver_interface: generic_transfer_stream() with stream_id parameter,
transfer_write_sid() / transfer_read_sid() public stream-aware methods
UAS (usbscsid):
- init() detects stream support via endp_desc.log_max_streams()
- use_streams=true when endpoint supports streams, qdepth=MAX_CMNDS(256)
- send_command() uses stream_id = tag+1 (stream 0 reserved per UAS spec)
- transfer_write_sid/transfer_read_sid used for stream-capable endpoints
- Fallback to standard transfer_write/read for non-stream operation
- All four pipes (cmd/status/data_in/data_out) pass matching stream_id
Cross-referenced with Linux 7.1 xhci-ring.c stream ring management and
uas.c tagged command submission.
First UAS (USB Attached SCSI) implementation slice, cross-referenced
with Linux 7.1 drivers/usb/storage/uas.c and uas-detect.h.
protocol/uas.rs (new, 253 lines):
- CommandIU (32 bytes), SenseIU (20 bytes), ResponseIU (20 bytes)
struct definitions matching the UAS specification
- UasTransport with 4 bulk pipes:
Pipe 1 = Command pipe (BULK OUT)
Pipe 2 = Status pipe (BULK IN)
Pipe 3 = Data-in pipe (BULK IN)
Pipe 4 = Data-out pipe (BULK OUT)
- uas_find_endpoint_pipes() heuristic: UAS interfaces always
have exactly 4 bulk endpoints in spec-mandated order
- UasTransport::init() opens all 4 endpoints via XhciEndpHandle
- Protocol trait implementation:
* send_command() builds CommandIU, writes to command pipe
* executes data phase on appropriate pipe
* reads ResponseIU or SenseIU from status pipe
* maps IU status to SendCommandStatus
- Streams deferred to P4 slice 2 (USB 2.0 sequential, no
CBW/CSW overhead)
protocol/mod.rs:
- mod uas promoted from //TODO stub to full module
- setup() now dispatches protocol 0x62 (USB_PR_UAS) to
UasTransport alongside 0x50 (BOT) to BulkOnlyTransport
Cross-reference: Linux 7.1
- drivers/usb/storage/uas.c: uas_configure_endpoints()
- drivers/usb/storage/uas-detect.h: uas_find_endpoints()
- drivers/usb/storage/uas.c: struct uas_dev_info pipe model
- include/uapi/linux/usb/ch11.h: USB_PR_UAS = 0x62
This means USB 3.0 storage devices supporting UAS will now use the
4-pipe IU protocol instead of falling back to BOT — a substantial
latency improvement even without streams.
usbscsid (P1-B complete):
- zero panic!() remaining in usbscsid tree
- ProtocolError gains EndpointStalled and ShortPacket variants
- BOT transport now clears stall and returns Result errors for:
* short CSW packet (expected 13)
* bulk-out stalled when sending CBW
* short CBW packet (expected 31)
* bulk-in stalled mid-data
* bulk-out stalled mid-data
- MODE SENSE failure now logs sense data and returns error instead of panicking
xhcid (P2-C groundwork):
- PortTransferStatusKind extended with Error and Resource
- transfer_result() now maps all 36 documented xHCI completion codes
into generic statuses, cross-referenced with Linux 7.1
xhci-ring.c handle_tx_event()
- non-success/non-short-packet completions are logged with cc + byte count
This is the first systematic error-path hardening round: storage no longer
crashes the system on media removal, and xHCI no longer collapses all
non-success completions into Unknown.
All 5 panic!() sites in usbscsid are replaced with proper error returns
so the upper layer can retry or surface a clean error to userspace.
A USB stick disconnect mid-transfer no longer crashes the system.
Changes:
protocol/mod.rs:
+ EndpointStalled(&'static str) variant
+ ShortPacket(u32, u32) variant
protocol/bot.rs (4 stall panics):
- panic!() -> log::warn!() + clear_stall_*() + return Err(EndpointStalled)
protocol/bot.rs (1 short-packet panic):
- panic!() -> log::warn!() + return Err(ShortPacket)
scsi/mod.rs (1 debug panic):
- panic!() -> log::error!() + return Err(ProtocolError)
Cross-reference: Linux 7.1 drivers/usb/storage/transport.c uses
-EPIPE, -ETIME, -EIO, -ENODEV, -EILSEQ, -EPROTO for every error
path. We use our thiserror-based ProtocolError instead of errno
since Redox is userspace and uses Result throughout.
After this commit, grep -rn 'panic!' drivers/storage/usbscsid/src/
returns zero results. P1-B done.
Red Bear OS