When an endpoint on a device under an xHCI host controller stalls, the
host controller driver must let the hardware know that the USB core has
successfully cleared the halt condition. The HCD submits a Reset Endpoint
Command, which will clear the toggle bit for USB 2.0 devices, and set the
sequence number to zero for USB 3.0 devices.
The xHCI urb_enqueue will accept new URBs while the endpoint is halted,
and will queue them to the hardware rings. However, the endpoint doorbell
will not be rung until the Reset Endpoint Command completes.
Don't queue a reset endpoint command for root hubs. khubd clears halt
conditions on the roothub during the initialization process, but the roothub
isn't a real device, so the xHCI host controller doesn't need to know about the
cleared halt.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The 0.95 xHCI specification requires software to set the "TD size" field
in each transaction request block (TRB). This field gives the host
controller an indication of how much data is remaining in the TD
(including the buffer in the current TRB). Set this field in bulk TRBs
and data stage TRBs for control transfers.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Greg KH introduced a bug into xhci_trb_virt_to_dma() when he changed the
type of offset to dma_addr_t from unsigned int and dropped the casts to
unsigned int around the virtual address pointer subtraction.
trb and seg->trbs are both valid pointers to virtual addresses, so the
compiler will mod the subtraction by the size of union trb (16 bytes).
segment_offset is an unsigned long, which is guaranteed to be at least as
big as a void *.
Drop the void * casts in the first if statement because trb and seg->trbs
are both pointers of the same type (pointers to union trb).
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Force the compiler to write the cycle bit of the Link TRB last. This
ensures that the hardware doesn't think it owns the Link TRB before we set
the chain bit. Reported by Oliver in this thread:
http://marc.info/?l=linux-usb&m=124091532410219&w=2
Reported-by: Oliver Neukum <oliver@neukum.org>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Make all globally visible functions start with xhci_ and mark functions as
static if they're only called within the same C file. Fix some long lines
while we're at it.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Make sure to preserve all bits *except* the TRB_CHAIN bit when giving a
Link TRB to the hardware. We need to save things like TRB type and the
toggle bit in the control dword.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Turns out someone never built this code on a 64bit platform.
Someone owes me a beer...
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The former is way to generic for a global symbol.
Fixes this build error:
drivers/usb/built-in.o: In function `.handle_event': (.text+0x67dd0): multiple definition of `.handle_event'
drivers/pcmcia/built-in.o:(.text+0xcfcc): first defined here
drivers/usb/built-in.o: In function `handle_event': (.opd+0x5bc8): multiple definition of `handle_event'
drivers/pcmcia/built-in.o:(.opd+0xed0): first defined here
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Add URB cancellation support to the xHCI host controller driver. This
currently supports cancellation for endpoints that do not have streams
enabled.
An URB is represented by a number of Transaction Request Buffers (TRBs),
that are chained together to make one (or more) Transaction Descriptors
(TDs) on an endpoint ring. The ring is comprised of contiguous segments,
linked together with Link TRBs (which may or may not be chained into a TD).
To cancel an URB, we must stop the endpoint ring, make the hardware skip
over the TDs in the URB (either by turning them into No-op TDs, or by
moving the hardware's ring dequeue pointer past the last TRB in the last
TD), and then restart the ring.
There are times when we must drop the xHCI lock during this process, like
when we need to complete cancelled URBs. We must ensure that additional
URBs can be marked as cancelled, and that new URBs can be enqueued (since
the URB completion handlers can do either). The new endpoint ring
variables cancels_pending and state (which can only be modified while
holding the xHCI lock) ensure that future cancellation and enqueueing do
not interrupt any pending cancellation code.
To facilitate cancellation, we must keep track of the starting ring
segment, first TRB, and last TRB for each URB. We also need to keep track
of the list of TDs that have been marked as cancelled, separate from the
list of TDs that are queued for this endpoint. The new variables and
cancellation list are stored in the xhci_td structure.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Add support for bulk URBs that pass scatter gather lists to xHCI. This allows
xHCI to more efficiently enqueue these transfers, and allows the host
controller to take advantage of USB 3.0 "bursts" for bulk endpoints.
Use requested length to calculate the number of TRBs needed for a scatter gather
list transfer, instead of using the number of sglist entries. The application
can pass down a scatter gather list that is bigger than it needs for the
requested transfer.
Scatter gather entries can cross 64KB boundaries, so be careful to setup TRBs
such that no buffer crosses a 64KB boundary.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Allow device drivers to submit URBs to bulk endpoints on devices under an
xHCI host controller. Share code between the control and bulk enqueueing
functions when it makes sense.
To get the best performance out of bulk transfers, SuperSpeed devices must
have the bMaxBurst size copied from their endpoint companion controller
into the xHCI device context. This allows the host controller to "burst"
up to 16 packets before it has to wait for the device to acknowledge the
first packet.
The buffers in Transfer Request Blocks (TRBs) can cross page boundaries,
but they cannot cross 64KB boundaries. The buffer must be broken into
multiple TRBs if a 64KB boundary is crossed.
The sum of buffer lengths in all the TRBs in a Transfer Descriptor (TD)
cannot exceed 64MB. To work around this, the enqueueing code must enqueue
multiple TDs. The transfer event handler may incorrectly give back the
URB in this case, if it gets a transfer event that points somewhere in the
first TD. FIXME later.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Since the xHCI host controller hardware (xHC) has an internal schedule, it
needs a better representation of what devices are consuming bandwidth on
the bus. Each device is represented by a device context, with data about
the device, endpoints, and pointers to each endpoint ring.
We need to update the endpoint information for a device context before a
new configuration or alternate interface setting is selected. We setup an
input device context with modified endpoint information and newly
allocated endpoint rings, and then submit a Configure Endpoint Command to
the hardware.
The host controller can reject the new configuration if it exceeds the bus
bandwidth, or the host controller doesn't have enough internal resources
for the configuration. If the command fails, we still have the older
device context with the previous configuration. If the command succeeds,
we free the old endpoint rings.
The root hub isn't a real device, so always say yes to any bandwidth
changes for it.
The USB core will enable, disable, and then enable endpoint 0 several
times during the initialization sequence. The device will always have an
endpoint ring for endpoint 0 and bandwidth allocated for that, unless the
device is disconnected or gets a SetAddress 0 request. So we don't pay
attention for when xhci_check_bandwidth() is called for a re-add of
endpoint 0.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Allow device drivers to enqueue URBs to control endpoints on devices under
an xHCI host controller. Each control transfer is represented by a
series of Transfer Descriptors (TDs) written to an endpoint ring. There
is one TD for the Setup phase, (optionally) one TD for the Data phase, and
one TD for the Status phase.
Enqueue these TDs onto the endpoint ring that represents the control
endpoint. The host controller hardware will return an event on the event
ring that points to the (DMA) address of one of the TDs on the endpoint
ring. If the transfer was successful, the transfer event TRB will have a
completion code of success, and it will point to the Status phase TD.
Anything else is considered an error.
This should work for control endpoints besides the default endpoint, but
that hasn't been tested.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
xHCI needs to get a "Slot ID" from the host controller and allocate other
data structures for every USB device. Make usb_alloc_dev() and
usb_release_dev() allocate and free these device structures. After
setting up the xHC device structures, usb_alloc_dev() must wait for the
hardware to respond to an Enable Slot command. usb_alloc_dev() fires off
a Disable Slot command and does not wait for it to complete.
When the USB core wants to choose an address for the device, the xHCI
driver must issue a Set Address command and wait for an event for that
command.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Add functionality for getting port status and hub descriptor for xHCI root
hubs. This is WIP because the USB 3.0 hub descriptor is different from
the USB 2.0 hub descriptor. For now, we lie about the root hub descriptor
because the changes won't effect how the core talks to the root hub.
Later we will need to add the USB 3.0 hub descriptor for real hubs, and
this code might change.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
xHCI host controllers can optionally implement a no-op test. This
simple test ensures the OS has correctly setup all basic data structures
and can correctly respond to interrupts from the host controller
hardware.
There are two rings exercised by the no-op test: the command ring, and
the event ring.
The host controller driver writes a no-op command TRB to the command
ring, and rings the doorbell for the command ring (the first entry in
the doorbell array). The hardware receives this event, places a command
completion event on the event ring, and fires an interrupt.
The host controller driver sees the interrupt, and checks the event ring
for TRBs it can process, and sees the command completion event. (See
the rules in xhci-ring.c for who "owns" a TRB. This is a simplified set
of rules, and may not contain all the details that are in the xHCI 0.95
spec.)
A timer fires every 60 seconds to debug the state of the hardware and
command and event rings. This timer only runs if
CONFIG_USB_XHCI_HCD_DEBUGGING is 'y'.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Sarah Sharp