If neither the IRQ line nor the scheme surface has produced activity
for TX_WATCHDOG_SECS, log a warning. This is a much weaker contract
than the Linux NET_TX_TIMEOUT (which resets the device), but it does
three things the previous code did not:
1. Detects the silent-stall failure mode that the original 2019
port has (no TX reclaim on dead TX descriptors) and surfaces it
in the log.
2. Forces the next event-loop iteration to call scheme.tick()
which exercises the transmit ring.
3. Provides a single counter and threshold that can be wired into
a real NET_TX_TIMEOUT handler (reset CTRL, re-init descriptors,
re-enable TX) in a follow-up without changing the call sites.
The watchdog is per-event (cheap; one Instant::now() comparison per
loop iteration) and self-resets the moment any IRQ or scheme op
arrives, so on a healthy bus the warning never fires.
Without explicit memory ordering, the Rust compiler is free to
reorder loads of the device-written descriptor (status, length)
relative to the writeback of the descriptor ownership flag. On
x86 the resulting tearing is usually invisible (the CPU serializes
implicitly), but on aarch64 with relaxed ordering, or on any
architecture with a future writeback-cache or snoop filter, the
RX path can read a length that does not yet match the status it
just observed, and the TX path can ring the doorbell before the
descriptor's length is visible to the NIC.
Dma::sync_for_cpu() is the acquire barrier called before reading
the completion status; Dma::sync_for_device() is the release
barrier called before ringing TDT or RDT. These are the same
fences the Linux e1000e driver places around doorbell writes and
descriptor status reads, and they are cheap (single compiler
fence, no real CPU cost).
Same bug class as the ahcid fix (ad40fffd): the kernel masks the IRQ
line when it delivers an interrupt and only re-arms it on the userspace
write-back (irq scheme write -> acknowledge() -> pic/ioapic_unmask).
When a driver acks only if the interrupt was its own, one foreign
interrupt on a shared INTx line leaves the line masked forever and all
later interrupts for the device are lost.
- e1000d: ack unconditionally; ICR is read-to-clear, so the ownership
check doubles as the device-level status clear
- ihdad: ack before the not-ours continue
- vboxd: ack unconditionally; device-side ack and event handling stay
conditional on host_events
- xhcid: ack unconditionally in the IRQ reactor; for INTx the ownership
check already clears IMAN.IP (RW1C) and device interrupts are masked
before re-arming, so no storm. MSI/MSI-X vectors are never shared, so
behavior there is unchanged (every delivery is ours by construction)
Verified: cargo check -Z build-std --target x86_64-unknown-redox for
e1000d, ihdad, vboxd, xhcid — clean, no new warnings.
- smolnetd: an empty ip_router (DHCP-managed or deliberately network-less like
the bare target) is a valid 'no default gateway' state, not a malformed config
-> no warning.
- router: a limited/directed IPv4 broadcast (DHCP DISCOVER to 255.255.255.255
before any lease/route exists) legitimately has no routing-table entry; don't
warn 'No route found' for broadcast destinations.
- e1000d: add the 82574L (0x10d3, QEMU '-device e1000e') to the E1000 match
list; it keeps the legacy descriptor/register interface this driver uses.
I219 is intentionally excluded (integrated MDIO PHY, different init).
Per local/docs/PATCH-PRESERVATION-AUDIT-2026-07-12.md the base
fork was carrying only 38 of 100 patches in local/patches/base/.
The other 62 patches' content was silently missing from the fork
working tree, even though their .patch files were preserved.
This commit re-applies 41 patches that genuinely still apply
cleanly + 17 hunks that partially applied. Recovery covers:
- D-Bus initfs service wiring (P4-initfs-dbus-services)
- USB service wiring (P4-initfs-usb-drm-services)
- netcfg/dhcp/dhcpv6 driver fixes
- acpid shutdown/PM/quirk fixes
- inputd/ps2d hard-fail logging
- pcid driver interface refinements (server cmd channel)
- virtio-core for VirtualBox support
- ixgbed/rtl8139/rtl8168 net drivers
- ahcid NCQ + per-function interrupt coalescing
- logd persistent logging
- bootstrap procmgr race-condition fixes
- cargo version pin to +rb0.3.0 (synchronized release branch)
58 files changed, +1444/-318 lines.
Untracked mnt/ tree and *.orig / *.rej files cleaned up after
patch application (leftover from absolute-path patch headers).
Red Bear OS