Section 4.11.7.1 of rev 1.0 of the xhci specification states that a link TRB
can only occur at a boundary between underlying USB frames (512 bytes for
high speed devices).

If this isn't done the USB frames aren't formatted correctly and, for example,
the USB3 ethernet ax88179_178a card will stop sending (while still receiving)
when running a netperf tcp transmit test with (say) and 8k buffer.

This should be a candidate for stable, the ax88179_178a driver defaults to
gso and tso enabled so it passes a lot of fragmented skb to the USB stack.

Notes from Sarah:

Discussion: http://marc.info/?l=linux-usb&m=138384509604981&w=2

This patch fixes a long-standing xHCI driver bug that was revealed by a
change in 3.12 in the usb-net driver.  Commit
638c5115 "USBNET: support DMA SG" added
support to use bulk endpoint scatter-gather (urb->sg).  Only the USB
ethernet drivers trigger this bug, because the mass storage driver sends
sg list entries in page-sized chunks.

This patch only fixes the issue for bulk endpoint scatter-gather.  The
problem will still occur for periodic endpoints, because hosts will
interpret no-op transfers as a request to skip a service interval, which
is not what we want.

Luckily, the USB core isn't set up for scatter-gather on isochronous
endpoints, and no USB drivers use scatter-gather for interrupt
endpoints.  Document this known limitation so that developers won't try
to use urb->sg for interrupt endpoints until this issue is fixed.  The
more comprehensive fix would be to allow link TRBs in the middle of the
endpoint ring and revert this patch, but that fix would touch too much
code to be allowed in for stable.

This patch should be backported to kernels as old as 3.12, that contain
the commit 638c5115 "USBNET: support DMA
SG".  Without this patch, the USB network device gets wedged, and stops
sending packets.  Mark Lord confirms this patch fixes the regression:

http://marc.info/?l=linux-netdev&m=138487107625966&w=2Signed-off-by: NDavid Laight <david.laight@aculab.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Tested-by: NMark Lord <mlord@pobox.com>
Cc: stable@vger.kernel.org

Perform an unconditional toggle of the cycle bit with 'xor'.
Signed-off-by: NDan Williams <dan.j.williams@intel.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>

This patch replaces the 'event' argument of xhci_handle_cmd_set_deq() and
xhci_handle_cmd_reset_ep(), which is used to retrieve the command completion
status code, with the cmd_comp_code directly, since it is available.
Signed-off-by: NXenia Ragiadakou <burzalodowa@gmail.com>
Acked-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>

Since the Slot ID field in the command completion event matches the Slot ID
field in the associated command TRB for the Stop Endpoint, Set Dequeue Pointer
and Reset Endpoint commands, this patch adds in the handlers of their
completion events a 'slot_id' argument and removes the slot id calculation
in each of them.
Also, a WARN_ON() was added in case the slot ids reported by command TRB and
event TRB differ (although according to xhci spec rev1.0 that should not happen)
Signed-off-by: NXenia Ragiadakou <burzalodowa@gmail.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>

This patch replaces 'xhci->cmd_ring->dequeue' with 'trb', the address of
the command TRB, since it is available to reduce line length.
Signed-off-by: NXenia Ragiadakou <burzalodowa@gmail.com>
Acked-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>

This patch adds a new variable 'cmd_type' to hold the command type so that
switch cases can be simplified by removing TRB_TYPE() macro improving
code readability.
Signed-off-by: NXenia Ragiadakou <burzalodowa@gmail.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>

This patch adds a new variable 'cmd_trb' to hold the address of the
command TRB, that is associated with the command completion event,
and to replace repetitions of xhci->cmd_ring->dequeue into the code.
Signed-off-by: NXenia Ragiadakou <burzalodowa@gmail.com>
Acked-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>

This patch adds a new variable 'cmd_comp_code' to hold the command completion
status code aiming to reduce code duplication and to improve code readability.
Signed-off-by: NXenia Ragiadakou <burzalodowa@gmail.com>
Acked-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>

The function that handles xHCI command completion is much too long and
there is need to be broken up into individual functions for each command
completion to improve code readablity.
This patch refactors the code in TRB_CONFIG_EP switch case, in
handle_cmd_completion(), into a fuction named xhci_handle_cmd_config_ep().

There were added two additional variables, 'add_flags' and 'drop_flags',
to reduce line length below 80 chars and improve code readability.
Signed-off-by: NXenia Ragiadakou <burzalodowa@gmail.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>

This patch removes the variable 'ep_ring' that is assigned in
TRB_CONFIG_EP switch case but never used.
Signed-off-by: NXenia Ragiadakou <burzalodowa@gmail.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>

The function that handles xHCI command completion is much too long and
there is need to be broken up into individual functions for each command
completion to improve code readablity.
This patch refactors the code in TRB_EVAL_CONTEXT switch case in
handle_cmd_completion() into a fuction named xhci_handle_cmd_eval_ctx().
Signed-off-by: NXenia Ragiadakou <burzalodowa@gmail.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>

The function that handles xHCI command completion is much too long and
there is need to be broken up into individual functions for each command
completion to improve code readablity.
This patch refactors the code in TRB_NEC_GET_FW switch case in
handle_cmd_completion() into a fuction named xhci_handle_cmd_nec_get_fw().
Signed-off-by: NXenia Ragiadakou <burzalodowa@gmail.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>

The function that handles xHCI command completion is much too long and
there is need to be broken up into individual functions for each command
completion to improve code readablity.
This patch refactors the code in TRB_RESET_DEV switch case in
handle_cmd_completion() into a fuction named xhci_handle_cmd_reset_dev().
Signed-off-by: NXenia Ragiadakou <burzalodowa@gmail.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>

Since the slot id retrieved from the Reset Device TRB matches the slot id in
the command completion event, which is available, there is no need to determine
it again.
This patch removes the uneccessary reassignment to slot id and adds a WARN_ON
in case the two Slot ID fields differ (although according xhci spec rev1.0
they should not differ).
Signed-off-by: NXenia Ragiadakou <burzalodowa@gmail.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>

The function that handles xHCI command completion is much too long and
there is need to be broken up into individual functions for each command
completion to improve code readablity.
This patch refactors the code in TRB_ADDR_DEV switch case in
handle_cmd_completion() into a fuction named xhci_handle_cmd_addr_dev().
Signed-off-by: NXenia Ragiadakou <burzalodowa@gmail.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>

The function that handles xHCI command completion is much too long and
there is need to be broken up into individual functions for each command
completion to improve code readablity.
This patch refactors the code in TRB_DISABLE_SLOT switch case in
handle_cmd_completion() into a fuction named xhci_handle_cmd_disable_slot().
Signed-off-by: NXenia Ragiadakou <burzalodowa@gmail.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>

The function that handles xHCI command completion is much too long and
there is need to be broken up into individual functions for each command
completion to improve code readablity.
This patch refactors the code in TRB_ENABLE_SLOT switch case in
handle_cmd_completion() into a fuction named xhci_handle_cmd_enable_slot().
Signed-off-by: NXenia Ragiadakou <burzalodowa@gmail.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>

This patch renames the function handlers of a triggered Command Completion
Event that correspond to each command type into 'xhci_handle_cmd_<type>'.
That is done to give a consistent naming space to all the functions that
handle Command Completion Events and that will permit the code reader to
reference to them more easily.
Signed-off-by: NXenia Ragiadakou <burzalodowa@gmail.com>
Acked-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>

This patch removes the "adjective" argument from xhci_giveback_urb_in_irq(),
since it is not used in the function anymore.
Signed-off-by: NXenia Ragiadakou <burzalodowa@gmail.com>
Acked-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>

The halted state of a endpoint cannot be cleared over CLEAR_HALT from a
user process, because the stopped_td variable was overwritten in the
handle_stopped_endpoint() function. So the xhci_endpoint_reset() function will
refuse the reset and communication with device can not run over this endpoint.
https://bugzilla.kernel.org/show_bug.cgi?id=60699Signed-off-by: NFlorian Wolter <wolly84@web.de>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>

When a device signals remote wakeup on a roothub, and the suspend change
bit is set, the host controller driver must not give control back to the
USB core until the port goes back into the active state.

EHCI accomplishes this by waiting in the get port status function until
the PORT_RESUME bit is cleared:

                        /* stop resume signaling */
                        temp &= ~(PORT_RWC_BITS | PORT_SUSPEND | PORT_RESUME);
                        ehci_writel(ehci, temp, status_reg);
                        clear_bit(wIndex, &ehci->resuming_ports);
                        retval = ehci_handshake(ehci, status_reg,
                                        PORT_RESUME, 0, 2000 /* 2msec */);

Similarly, the xHCI host should wait until the port goes into U0, before
passing control up to the USB core.  When the port transitions from the
RExit state to U0, the xHCI driver will get a port status change event.
We need to wait for that event before passing control up to the USB
core.

After the port transitions to the active state, the USB core should time
a recovery interval before it talks to the device.  The length of that
recovery interval is TRSMRCY, 10 ms, mentioned in the USB 2.0 spec,
section 7.1.7.7.  The previous xHCI code (which did not wait for the
port to go into U0) would cause the USB core to violate that recovery
interval.

This bug caused numerous USB device disconnects on remote wakeup under
ChromeOS and a Lynx Point LP xHCI host that takes up to 20 ms to move
from RExit to U0.  ChromeOS is very aggressive about power savings, and
sets the autosuspend_delay to 100 ms, and disables USB persist.

I attempted to replicate this bug with Ubuntu 12.04, but could not.  I
used Ubuntu 12.04 on the same platform, with the same BIOS that the bug
was triggered on ChromeOS with.  I also changed the USB sysfs settings
as described above, but still could not reproduce the bug under Ubuntu.
It may be that ChromeOS userspace triggers this bug through additional
settings.
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>

If a command on the command ring needs to be cancelled before it is handled
it can be turned to a no-op operation when the ring is stopped.
We want to store the command ring enqueue pointer in the command structure
when the command in enqueued for the cancellation case.

Some commands used to store the command ring dequeue pointers instead of enqueue
(these often worked because enqueue happends to equal dequeue quite often)

Other commands correctly used the enqueue pointer but did not check if it pointed
to a valid trb or a link trb, this caused for example stop endpoint command to timeout in
xhci_stop_device() in about 2% of suspend/resume cases.

This should also solve some weird behavior happening in command cancellation cases.

This patch is based on a patch submitted by Sarah Sharp to linux-usb, but
then forgotten:
    http://marc.info/?l=linux-usb&m=136269803207465&w=2

This patch should be backported to kernels as old as 3.7, that contain
the commit b92cc66c "xHCI: add aborting
command ring function"
Signed-off-by: NMathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: stable@vger.kernel.org

When a command times out, the command ring is first aborted,
and then stopped. If the command ring is empty when it is stopped
the stop event will point to next command which is not yet set.
xHCI tries to handle this next event often causing an oops.

Don't handle command completion events on stopped cmd ring if ring is
empty.

This patch should be backported to kernels as old as 3.7, that contain
the commit b92cc66c "xHCI: add aborting
command ring function"
Signed-off-by: NMathias Nyman <mathias.nyman@linux.intel.com>
Reported-by: NGiovanni <giovanni.nervi@yahoo.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: stable@vger.kernel.org

When debug is not enabled and dev_dbg() will expand to nothing,
log might be flooded with "callbacks suppressed". If it was not
done on purpose, better to use dev_dbg_ratelimited() instead.
Signed-off-by: NDmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>

This patch defines a new trace event, which is called xhci_dbg_ring_expansion
and belongs to the event class xhci_log_msg, and adds tracepoints that trace
the debug messages associated with the expansion of endpoint ring when there
is not enough space allocated to hold all pending TRBs.
Signed-off-by: NXenia Ragiadakou <burzalodowa@gmail.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>

This patch defines a new trace event, which is called xhci_dbg_cancel_urb
and belongs to the event class xhci_log_msg, and adds tracepoints that
trace the debug messages related to the removal of a cancelled URB from
the endpoint's transfer ring.
Signed-off-by: NXenia Ragiadakou <burzalodowa@gmail.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>

This patch creates a new event class, called xhci_log_event,
and defines the xhci_cmd_completion trace event used for
tracing the commands issued to xHC that generate a completion
event in the event ring.

This info can be used, later, to print, in a human readable
way, the completion status and flags as well as the command's
type and fields using the trace-cmd tool and the appropriate
plugin.

Also, a tracepoint is added in handle_cmd_completion().
Signed-off-by: NXenia Ragiadakou <burzalodowa@gmail.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>

This patch defines a new trace event, which is called xhci_dbg_reset_ep
and belongs in the event class xhci_log_msg, and adds tracepoints that
trace the debug messages associated with resetting an endpoint after
the reception of a STALL packet.
Signed-off-by: NXenia Ragiadakou <burzalodowa@gmail.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>

This patch defines a new trace event, which is called xhci_dbg_quirks
and belongs in the event class xhci_log_msg, and adds tracepoints that
trace the debug messages associated with xHCs' quirks.
Signed-off-by: NXenia Ragiadakou <burzalodowa@gmail.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>

This patch defines a new trace event, which is called xhci_dbg_context_change
and belongs in the event class xhci_log_msg, and adds tracepoints for tracing
the debug messages related to context updates performed with Configure Endpoint
and Evaluate Context commands.
Signed-off-by: NXenia Ragiadakou <burzalodowa@gmail.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>

in some cases where device is attched to xhci port and do not responding,
for example ath9k_htc with stalled firmware, kernel will
crash on ring_doorbell_for_active_rings.
This patch check if pointer exist before it is used.

This patch should be backported to kernels as old as 2.6.35, that
contain the commit e9df17eb "USB: xhci:
Correct assumptions about number of rings per endpoint"
Signed-off-by: NOleksij Rempel <linux@rempel-privat.de>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: stable@vger.kernel.org

Fail gracefully, instead of causing the kernel to panic, if the input
control context doesn't have the right type (XHCI_CTX_TYPE_INPUT).  Push
finding the pointer to the input control context up into functions that
can fail.
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: John Youn <johnyoun@synopsys.com>

According to Felipe and Alan's comments the second parameter of irq
handler should be 'void *' not a specific structure pointer.
So change it.
Signed-off-by: NAlex Shi <alex.shi@intel.com>
Acked-by: NFelipe Balbi <balbi@ti.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>

When a device attached to the roothub is suspended, the endpoint rings
are stopped.  The host may generate a completion event with the
completion code set to 'Stopped' or 'Stopped Invalid' when the ring is
halted.  The current xHCI code prints a warning in that case, which can
be really annoying if the USB device is coming into and out of suspend.

Remove the unnecessary warning.
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Tested-by: NStephen Hemminger <stephen@networkplumber.org>

Use proper macro while extracting TRB transfer length from
Transfer event TRBs. Adding a macro EVENT_TRB_LEN (bits 0:23)
for the same, and use it instead of TRB_LEN (bits 0:16) in
case of event TRBs.

This patch should be backported to kernels as old as 2.6.31, that
contain the commit b10de142 "USB: xhci:
Bulk transfer support".  This patch will have issues applying to older
kernels.
Signed-off-by: NVivek gautam <gautam.vivek@samsung.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: stable@vger.kernel.org

/home/b29397/work/code/git/linus/linux-2.6/drivers/usb/host/xhci-ring.c: In function ‘handle_port_status’:
/home/b29397/work/code/git/linus/linux-2.6/drivers/usb/host/xhci-ring.c:1580: warning: ‘hcd’ may be used uninitialized in this function
Signed-off-by: NPeter Chen <peter.chen@freescale.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>

This patch (as1640) fixes a memory leak in xhci-hcd.  The urb_priv
data structure isn't always deallocated in the handle_tx_event()
routine for non-control transfers.  The patch adds a kfree() call so
that all paths end up freeing the memory properly.

This patch should be backported to kernels as old as 2.6.36, that
contain the commit 8e51adcc "USB: xHCI:
Introduce urb_priv structure"
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Reported-and-tested-by: NMartin Mokrejs <mmokrejs@fold.natur.cuni.cz>
CC: <stable@vger.kernel.org>

Fix incorrect bit test that originally showed up in
4ee823b8 "USB/xHCI: Support
device-initiated USB 3.0 resume."

Use '&' instead of '&&'.

This should be backported to kernels as old as 3.4.
Signed-off-by: NNickolai Zeldovich <nickolai@csail.mit.edu>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: stable@vger.kernel.org

To calculate the TD size for a particular TRB in an isoc TD, we need
know the endpoint's max packet size.  Isochronous endpoints also encode
the number of additional service opportunities in their wMaxPacketSize
field.  The TD size calculation did not mask off those bits before using
the field.  This resulted in incorrect TD size information for
isochronous TRBs when an URB frame buffer crossed a 64KB boundary.

For example:
 - an isoc endpoint has 2 additional service opportunites and
   a max packet size of 1020 bytes
 - a frame transfer buffer contains 3060 bytes
 - one frame buffer crosses a 64KB boundary, and must be split into
   one 1276 byte TRB, and one 1784 byte TRB.

The TD size is is the number of packets that remain to be transferred
for a TD after processing all the max packet sized packets in the
current TRB and all previous TRBs.

For this TD, the number of packets to be transferred is (3060 / 1020),
or 3.  The first TRB contains 1276 bytes, which means it contains one
full packet, and a 256 byte remainder.  After processing all the max
packet-sized packets in the first TRB, the host will have 2 packets left
to transfer.

The old code would calculate the TD size for the first TRB as:

total packet count = DIV_ROUND_UP (TD length / endpoint wMaxPacketSize)
total packet count - (first TRB length / endpoint wMaxPacketSize)

The math should have been:

total packet count = DIV_ROUND_UP (3060 / 1020) = 3
3 - (1276 / 1020) = 2

Since the old code didn't mask off the additional service interval bits
from the wMaxPacketSize field, the math ended up as

total packet count = DIV_ROUND_UP (3060 / 5116) = 1
1 - (1276 / 5116) = 1

Fix this by masking off the number of additional service opportunities
in the wMaxPacketSize field.

This patch should be backported to stable kernels as old as 3.0, that
contain the commit 4da6e6f2 "xhci 1.0:
Update TD size field format."  It may not apply well to kernels older
than 3.2 because of commit 29cc8897
"USB: use usb_endpoint_maxp() instead of le16_to_cpu()".
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: stable@vger.kernel.org

An isochronous TD is comprised of one isochronous TRB chained to zero or
more normal TRBs.  Only the isoc TRB has the TBC and TLBPC fields.  The
normal TRBs must set those fields to zeroes.  The code was setting the
TBC and TLBPC fields for both isoc and normal TRBs.  Fix this.

This should be backported to stable kernels as old as 3.0, that contain
the commit b61d378f " xhci 1.0: Set
transfer burst last packet count field."
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: stable@vger.kernel.org