[xhci] Consume event TRB before reporting completion to USB core
Reporting a completion via usb_complete() will pass control outside
the scope of xhci.c, and could potentially result in a further call to
xhci_event_poll() before returning from usb_complete(). Since we
currently update the event consumer counter only after calling
usb_complete(), this can result in duplicate completions and
consequent corruption of the submission TRB ring structures.
Fix by updating the event ring consumer counter before passing control
to usb_complete().
Reported-by: Andreas Hammarskjöld <junior@2PintSoftware.com>
Tested-by: Andreas Hammarskjöld <junior@2PintSoftware.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[xhci] Assume an invalid PSI table if any invalid PSI value is observed
Invalid protocol speed ID tables appear to be increasingly common in
the wild, to the point that it is infeasible to apply an explicit
XHCI_BAD_PSIV flag for each offending PCI device ID.
Fix by assuming an invalid PSI table as soon as any invalid value is
reported by the hardware.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[xhci] Ensure that zero-length packets are not part of a TRB chain
Some xHCI controllers (such as qemu's emulated xHCI controller) do not
correctly handle zero-length packets that are part of a TRB chain.
The zero-length TRB ends up being squashed and does not result in a
zero-length packet as seen by the device.
Work around this problem by marking the zero-length packet as
belonging to a separate transfer descriptor.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[usb] Allow additional settling time for out-of-spec hubs
Some hubs (e.g. the Avocent Corp. Virtual Hub on a Lenovo x3550
Integrated Management Module) have been observed to require more than
the standard 200ms for ports to stabilise, with the result that
devices appear to disconnect and immediately reconnect during the
initial bus enumeration.
Work around this problem by allowing specific hubs an extra 500ms of
settling time.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[usb] Record USB device speed separately from current port speed
Record the speed of a USB device based on the port's speed at the time
that the device was enabled. This allows us to remember the device's
speed even after the device has been disconnected (and so the port's
current speed has changed).
In particular, this allows us to correctly identify the transaction
translator for a low-speed or full-speed device after the device has
been disconnected.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[usb] Use port->disconnected to check for disconnected devices
The usb_message() and usb_stream() functions currently check for
port->speed==USB_SPEED_NONE to determine whether or not a device has
been unplugged. This test will give a false negative result if a new
device has been plugged in before the hotplug mechanism has finished
handling the removal of the old device.
Fix by checking instead the port->disconnected flag, which is now
cleared only after completing the removal of the old device.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Make the class ID a property of the USB driver (rather than a property
of the USB device ID), and allow USB drivers to specify a wildcard ID
for any of the three component IDs (class, subclass, or protocol).
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[usb] Select preferred USB device configuration based on driver score
Generate a score for each possible USB device configuration based on
the available driver support, and select the configuration with the
highest score. This will allow us to prefer ECM over RNDIS (for
devices which support both) and will allow us to meaningfully select a
configuration even when we have drivers available for all functions
(e.g. when exposing unused functions via EFI_USB_IO_PROTOCOL).
Signed-off-by: Michael Brown <mcb30@ipxe.org>
The decision on whether or not a zero-length packet needs to be
transmitted is independent of the host controller and belongs in the
USB core.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[efi] Add a USB host controller driver based on EFI_USB_IO_PROTOCOL
Allow iPXE to coexist with other USB device drivers, by attaching to
the EFI_USB_IO_PROTOCOL instances provided by the UEFI platform
firmware.
The EFI_USB_IO_PROTOCOL is an unsurprisingly badly designed
abstraction of a USB device. The poor design choices intrinsic in the
UEFI specification prevent efficient operation as a network device,
with the result that devices operated using the EFI_USB_IO_PROTOCOL
operate approximately two orders of magnitude slower than devices
operated using our native EHCI or xHCI host controller drivers.
Since the performance is so abysmally slow, and since the underlying
problems are due to fundamental architectural mistakes in the UEFI
specification, support for the EFI_USB_IO_PROTOCOL host controller
driver is left as disabled by default. Users are advised to use the
native iPXE host controller drivers instead.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[xhci] Ignore invalid protocol speed ID values on Intel Skylake platforms
Some Intel Skylake platforms (observed on a prototype Lenovo ThinkPad)
report the list of available USB3 protocol speed ID values as {1,2,3}
but then report a port's speed using ID value 4.
The value 4 happens to be the default value for SuperSpeed (when no
protocol speed ID value list is explicitly defined), and the hardware
seems to function correctly if we simply ignore its protocol speed ID
table and assume that it uses the default values.
Fix by adding a "broken PSI values" quirk for this controller.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[xhci] Fix comparison of signed and unsigned integers
gcc 4.8.2 fails to report this erroneous comparison unless assertions
are enabled.
Reported-by: Mary-Ann Johnson <MaryAnn.Johnson@displaylink.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
The xHCI slot ID is one-based, not zero-based. Fix the length of the
xhci->slot[] array to account for this, and add assertions to check
that the hardware returns a valid slot ID in response to the Enable
Slot command.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
When USB network card drivers are used, the BIOS' legacy USB
capability is necessarily disabled since there is no way to share the
host controller between the BIOS and iPXE. This currently results in
USB keyboards becoming non-functional in USB-enabled builds of iPXE.
Fix by adding basic support for USB keyboards, enabled by default in
iPXE builds which include USB support.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
The USB core will currently fail to detect disconnections if a new
device has attached by the time the port is examined in
usb_hotplug().
Fix by recording the fact that a disconnection has taken place
whenever the "connection status changed" (CSC) bit is observed to be
set. (Whether the change represents a disconnection or a
reconnection, it indicates that the port has experienced some time of
being disconnected.)
Note that the time at which a disconnection can be detected varies by
hub type. In particular: root hubs can observe the CSC bit when
polling, and so will record the disconnection before calling
usb_port_changed(), but USB hubs read the port status (and hence the
CSC bit) only during the call to hub_speed(), long after the call to
usb_port_changed().
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[pci] Provide PCI_CLASS() to calculate a scalar PCI class value
Rename PCI_CLASS() (which constructs a struct pci_class_id) to
PCI_CLASS_ID(), and provide PCI_CLASS() as a macro which constructs
the 24-bit scalar value of a PCI class code.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[usb] Include setup packet within I/O buffer for message transfers
The USB API currently assumes that host controllers will have
immediate data buffer space available in which to store the setup
packet. This is true for xHCI, partially true for EHCI (which happens
to have 12 bytes of padding in each transfer descriptor due to
alignment requirements), and not true at all for UHCI.
Include the setup packet within the I/O buffer passed to the host
controller's message() method, thereby eliminating the requirement for
host controllers to provide immediate data buffers.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
In theory USB3 ports do not require a reset to enable the port.
Experimentation shows that this is sometimes required, particularly
when rerouting ports from EHCI to xHCI and switching speeds.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[xhci] Support USB1 devices attached via transaction translators
xHCI provides a somewhat convoluted mechanism for specifying details
of a transaction translator. Hubs must be marked as such in the
device slot context. The only opportunity to do so is as part of a
Configure Endpoint command, which can be executed only when opening
the hub's interrupt endpoint.
We add a mechanism for host controllers to intercept the opening of
hub devices, providing xHCI with an opportunity to update the internal
device slot structure for the corresponding USB device to indicate
that the device is a hub. We then include the hub-specific details in
the input context whenever any Configure Endpoint command is issued.
When a device is opened, we record the device slot and port for its
transaction translator (if any), and supply these as part of the
Address Device command.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[ehci] Support USB1 devices attached via transaction translators
Support low-speed and full-speed devices attached to a USB2 hub. Such
devices use a transaction translator (TT) within the USB2 hub, which
asynchronously initiates transactions on the lower-speed bus and
returns the result via a split completion on the high-speed bus.
We make the simplifying assumption that there will never be more than
sixteen active interrupt endpoints behind a single transaction
translator; this assumption allows us to schedule all periodic start
splits in microframe 0 and all periodic split completions in
microframes 2 and 3. (We do not handle isochronous endpoints.)
Signed-off-by: Michael Brown <mcb30@ipxe.org>
The endpoint may already have enqueued TRBs at the time that
xhci_endpoint_reset() is called. Ring the doorbell to resume
processing these TRBs immediately, rather than waiting until the next
call to xhci_endpoint_message() or xhci_endpoint_stream().
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Several of the USB timeouts were chosen on the principle of "pick an
arbitrary but ridiculously large value, just to be safe". It turns
out that some of the timeouts permitted by the USB specification are
even larger: for example, control transactions are allowed to take up
to five seconds to complete.
Fix up these USB timeout values to match those found in the USB2
specification.
Debugged-by: Robin Smidsrød <robin@smidsrod.no>
Tested-by: Robin Smidsrød <robin@smidsrod.no>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[xhci] Do not release ownership back to BIOS when booting an OS
xHCI (and EHCI) nominally provide a mechanism for releasing ownership
of the host controller back to the BIOS, which can then potentially
restore legacy USB keyboard functionality.
This is a rarely used code path, since most operating systems claim
ownership and never attempt to later return to the BIOS. On some
systems (observed with a Lenovo X1 Carbon), this code path leads to
obscure and interesting bugs: if the xHCI and EHCI controllers are
both claimed and later released back to the BIOS, then a subsequent
call to INT 16,0305 to set the keyboard repeat rate to a non-default
value will lock the system.
Obscure though this sequence of operations may sound, it is exactly
what happens when using iPXE to boot a Linux kernel via a USB network
card. There is old and probably unwanted code in Linux's
arch/x86/boot/main.c which sets the keyboard repeat rate (with the
accompanying comment "Set keyboard repeat rate (why?)"). When booting
Linux via a USB network card on a Lenovo X1 Carbon, the system
therefore locks up immediately after jumping to the kernel's entry
point.
Work around this problem by preventing the release of ownership back
to the BIOS if it is known that we are shutting down to boot an OS.
This should allow legacy USB keyboard functionality to be restored if
the user chooses to exit iPXE, while avoiding the rarely used code
paths (and corresponding BIOS bugs) if the user chooses instead to
boot an OS.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[xhci] Forcibly disable SMIs if BIOS fails to release ownership
If the BIOS fails to gracefully release ownership of the xHCI
controller, we can forcibly claim it by disabling all SMIs via the
USB legacy support control/status register.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[xhci] Undo PCH-specific quirk fixes when removing device
Restore the original values of XUSB2PR and USB3PSSEN, in case we are
booting an OS with no support for xHCI.
Suggested-by: Dan Ellis <Dan.Ellis@displaylink.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[xhci] Enable USB3 ports on Intel PCH8/PCH9 controllers
Intel PCH controllers default to routing USB2 ports to EHCI rather
than xHCI, and default to disabling SuperSpeed connections.
Manipulate the PCI configuration space registers as necessary to
reroute ports and enable SuperSpeed.
Originally-fixed-by: Dan Ellis <Dan.Ellis@displaylink.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
When a command times out, abort it (via the Command Abort bit in the
Command Ring Control Register) so that subsequent commands may execute
as expected.
This improves robustness when a device fails to respond to the Set
Address command, since the subsequent Disable Slot command will now
succeed.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[xhci] Leak memory if controller fails to disable slot
If the Disable Slot command fails then the hardware may continue to
write to the slot context. Leak the memory used by the slot context
to avoid future memory corruption.
This situation has been observed in practice when a Set Address
command fails, causing the command ring to become temporarily
unresponsive.
Note that there is no need to similarly leak memory on the failure
path in xhci_device_open(), since in the event of a failure the
hardware is never informed of the slot context address.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Michael Brown