After the last architecture switched to generic hard irqs the config
options HAVE_GENERIC_HARDIRQS & GENERIC_HARDIRQS and the related code
for !CONFIG_GENERIC_HARDIRQS can be removed.
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

This patch removes the ehci statictics information output in ehci_stop()
because they do not provide interesting info. At any case, the current
statistics can be viewed by reading the 'registers' file in debugfs.
Signed-off-by: NXenia Ragiadakou <burzalodowa@gmail.com>
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This patch removes the duplicate of debug_async_open() prototype following
three lines below the debug_async_open() declaration.
Signed-off-by: NXenia Ragiadakou <burzalodowa@gmail.com>
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The debugging code for ehci is enabled to run if the DEBUG flag is defined.
This patch enables the debugging code also when the kernel is configured
with dynamic debugging on.
Signed-off-by: NXenia Ragiadakou <burzalodowa@gmail.com>
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This patch removes ehci_vdbg debugging statements from EHCI host controller
driver because they produce too much information, lowering the signal to noise
ratio when debugging, and because they are not used anymore.
Signed-off-by: NXenia Ragiadakou <burzalodowa@gmail.com>
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Use the wrapper functions for getting and setting the driver data using
platform_device instead of using dev_{get,set}_drvdata() with &of->dev,
so we can directly pass a struct platform_device.
Signed-off-by: NLibo Chen <libo.chen@huawei.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The 0day build server caught a new build warning that is triggered when
CONFIG_USB_DEFAULT_PERSIST is turned on:

tree:   git://git.kernel.org/pub/scm/linux/kernel/git/sarah/xhci.git for-usb-next
head:   0730d52a
commit: c8476fb8 [1/3] usb: xhci: Disable runtime PM suspend for quirky controllers
config: i386-randconfig-r6-0826 (attached as .config)

All warnings:

   drivers/usb/host/xhci.c: In function 'xhci_free_dev':
>> drivers/usb/host/xhci.c:3560:17: warning: unused variable 'dev' [-Wunused-variable]
     struct device *dev = hcd->self.controller;
                    ^
   drivers/usb/host/xhci.c: In function 'xhci_alloc_dev':
>> drivers/usb/host/xhci.c:3648:17: warning: unused variable 'dev' [-Wunused-variable]
     struct device *dev = hcd->self.controller;
                    ^

vim +/dev +3560 drivers/usb/host/xhci.c

  3554   * disabled.  Free any HC data structures associated with that device.
  3555   */
  3556  void xhci_free_dev(struct usb_hcd *hcd, struct usb_device *udev)
  3557  {
  3558          struct xhci_hcd *xhci = hcd_to_xhci(hcd);
  3559          struct xhci_virt_device *virt_dev;
> 3560          struct device *dev = hcd->self.controller;
  3561          unsigned long flags;
  3562          u32 state;
  3563          int i, ret;
  3564
  3565  #ifndef CONFIG_USB_DEFAULT_PERSIST
  3566          /*
  3567           * We called pm_runtime_get_noresume when the device was attached.
  3568           * Decrement the counter here to allow controller to runtime suspend
  3569           * if no devices remain.
  3570           */
  3571          if (xhci->quirks & XHCI_RESET_ON_RESUME)
  3572                  pm_runtime_put_noidle(dev);
  3573  #endif
  3574
...
  3641  /*
  3642   * Returns 0 if the xHC ran out of device slots, the Enable Slot command
  3643   * timed out, or allocating memory failed.  Returns 1 on success.
  3644   */
  3645  int xhci_alloc_dev(struct usb_hcd *hcd, struct usb_device *udev)
  3646  {
  3647          struct xhci_hcd *xhci = hcd_to_xhci(hcd);
> 3648          struct device *dev = hcd->self.controller;
  3649          unsigned long flags;
  3650          int timeleft;
  3651          int ret;

Fix this.
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: Shawn Nematbakhsh <shawnn@chromium.org>

Since ohci-hcd supports runtime PM, the .pm field in its pci_driver
structure should be protected by CONFIG_PM rather than
CONFIG_PM_SLEEP.

Without this change, OHCI controllers won't do runtime suspend if
system suspend or hibernation isn't enabled.
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
cc: <stable@vger.kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Unnecessary dev_set_drvdata() is removed, because the driver core
clears the driver data to NULL after device_release or on probe failure.
Signed-off-by: NLibo Chen <libo.chen@huawei.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.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>

Wrong capability bit was checked for best effort service latency.
bit 20 indicate port is BESL LPM capable (BLC),
bit 19 is hardware LPM capable (HLC)

This patch should be backported to kernels as old as 3.11, that
contain the commit a558ccdc "usb: xhci:
add USB2 Link power management BESL support"
Signed-off-by: NMathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Reported-by: NSteve Cotton <steve@s.cotton.clara.co.uk>
Cc: stable@vger.kernel.org

If a USB controller with XHCI_RESET_ON_RESUME goes to runtime suspend,
a reset will be performed upon runtime resume. Any previously suspended
devices attached to the controller will be re-enumerated at this time.
This will cause problems, for example, if an open system call on the
device triggered the resume (the open call will fail).

Note that this change is only relevant when persist_enabled is not set
for USB devices.

This patch should be backported to kernels as old as 3.0, that
contain the commit c877b3b2 "xhci: Add
reset on resume quirk for asrock p67 host".
Signed-off-by: NShawn Nematbakhsh <shawnn@chromium.org>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: stable@vger.kernel.org

Commit 9a11899c (USB: OHCI: add missing PCI PM callbacks to
ohci-pci.c) added missing ohci_suspend and ohci_resume callback
pointers, but forgot that these callbacks are declared and defined
only when CONFIG_PM is enabled.

This patch adds a preprocessor conditional to avoid build errors when
PM is disabled.
Reported-by: NGuenter Roeck <linux@roeck-us.net>
Tested-by: NGuenter Roeck <linux@roeck-us.net>
Reported-by: Meelis Roos <mroos@linux.ee>,
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Commit 7e8d5cd9 ("USB: Add EHCI support for MX27 and MX31 based
boards") introduced code that could potentially lead to a NULL pointer
dereference on driver removal.

Fix this by checking for the value of pdata before dereferencing it.
Signed-off-by: NDaniel Mack <zonque@gmail.com>
Reported-by: NDan Carpenter <dan.carpenter@oracle.com>
Cc: stable <stable@vger.kernel.org> # 2.6.33+
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Commit c1117afb (USB: OHCI: make ohci-pci a separate driver)
neglected to preserve the entries for the pci_suspend and pci_resume
driver callbacks.  As a result, OHCI controllers don't work properly
during suspend and after hibernation.

This patch adds the missing callbacks to the driver.
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
Reported-and-tested-by: NSteve Cotton <steve@s.cotton.clara.co.uk>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

use devm_get_clk() for automatic put upon device release, check for and
propagate errors when enabling clocks, must prepare clocks before they
can get enabled, unprepare after disable

need to use the _parent_ of the platform device for clock lookup, since
this one is associated with the respective device tree node; this change
remains neutral as long as a "globally" provided "usb%d_clk" item gets
provided by either the PPC_CLOCK implementation or clkdev_register'ed
aliases, using the correct devide and thus referencing the right DT node
becomes essential when clock lookup will become based on device tree
when common clock support will get introduced
Signed-off-by: NGerhard Sittig <gsi@denx.de>
Signed-off-by: NAnatolij Gustschin <agust@denx.de>

The xHCI platform driver calls into usb_add_hcd to register the irq for
its platform device.  It does not want the xHCI generic driver to
register an interrupt for it at all.  The original code did that by
setting the XHCI_BROKEN_MSI quirk, which tells the xHCI driver to not
enable MSI or MSI-X for a PCI host.

Unfortunately, if CONFIG_PCI is enabled, and CONFIG_USB_DW3 is enabled,
the xHCI generic driver will attempt to register a legacy PCI interrupt
for the xHCI platform device in xhci_try_enable_msi().  This will result
in a bogus irq being registered, since the underlying device is a
platform_device, not a pci_device, and thus the pci_device->irq pointer
will be bogus.

Add a new quirk, XHCI_PLAT, so that the xHCI generic driver can
distinguish between a PCI device that can't handle MSI or MSI-X, and a
platform device that should not have its interrupts touched at all.
This quirk may be useful in the future, in case other corner cases like
this arise.

This patch should be backported to kernels as old as 3.9, that
contain the commit 00eed9c8 "USB: xhci:
correctly enable interrupts".
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Reported-by: NYu Y Wang <yu.y.wang@intel.com>
Tested-by: NYu Y Wang <yu.y.wang@intel.com>
Reviewed-by: NFelipe Balbi <balbi@ti.com>
Cc: stable@vger.kernel.org

commit 9841f37a ("usb: ehci: Add support for SINGLE_STEP_SET_FEATURE
test of EHSET") added additional code to the EHCI hub driver but it is
anticipated to only have a limited audience (e.g. embedded silicon
vendors and integrators). Avoid subjecting all EHCI (and in the future
maybe xHCI/OHCI, etc.) HCD users to code bloat by conditionally
compiling the EHSET-specific additions with a new Kconfig option,
CONFIG_USB_HCD_TEST_MODE.
Signed-off-by: NJack Pham <jackp@codeaurora.org>
Acked-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The function dma_set_mask() tests internally whether the dma_mask pointer
for the device is initialized and fails if the dma_mask pointer is NULL.
On pci platforms, the device dma_mask pointer is initialized, when pci
devices are enumerated, to point to the pci_dev->dma_mask which is 0xffffffff.
However, for non-pci platforms, the dma_mask pointer may not be initialized
and in that case dma_set_mask() will fail.

This patch initializes the dma_mask and the coherent_dma_mask to 32bits
in xhci_plat_probe(), before the call to usb_create_hcd() that sets the
"uses_dma" flag for the usb bus and the call to usb_add_hcd() that creates
coherent dma pools for the usb hcd.

Moreover, a call to dma_set_mask() does not set the device coherent_dma_mask.
Since the xhci-hcd driver calls dma_alloc_coherent() and dma_pool_alloc()
to allocate consistent DMA memory blocks, the coherent DMA address mask
has to be set explicitly.

This patch sets the coherent_dma_mask to 64bits in xhci_gen_setup() when
the xHC is capable for 64-bit DMA addressing.

If dma_set_mask() succeeds, for a given bitmask, it is guaranteed that
the given bitmask is also supported for consistent DMA mappings.

Other changes introduced in this patch are:

- The return value of dma_set_mask() is checked to ensure that the required
  dma bitmask conforms with the host system's addressing capabilities.

- The dma_mask setup code for the non-primary hcd was removed since both
  primary and non-primary hcd refer to the same generic device whose
  dma_mask and coherent_dma_mask are already set during the setup of
  the primary hcd.

- The code for reading the HCCPARAMS register to find out the addressing
  capabilities of xHC was removed since its value is already cached in
  xhci->hccparams.

- hcd->self.controller was replaced with the dev variable since it is
  already available.
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_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_init
and belongs to the event class xhci_log_msg, and adds tracepoints that
trace the debug statements in the functions used to start and stop the
xhci-hcd driver.

Also, it removes an unnecessary cast of variable val to unsigned int
in xhci_mem_init(), since val is already declared as unsigned int.
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 event class, called xhci_log_ctx,
that records in the ring buffer the context data, the
context type (input or output), the context dma and virtual
addresses, the context endpoint entries, the slot ID and
whether the xHC uses 64 byte context data structures.

This information can be used, later, to parse and display
the context data fields with the appropriate plugin using
the trace-cmd tool.

Also, this patch defines a trace event, called xhci_address_ctx,
to trace the contexts related to the Address Device command and
adds the associated tracepoints in xhci_address_device().
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>

This patch declares an event class for trace events that
trace messages with variadic arguments, called xhci_log_msg,
and defines a trace event for tracing the debug messages in
xhci_address_device() function, called xhci_dbg_address.

In order to implement this type of trace events, a wrapper function,
called xhci_dbg_trace(), was created that records the format string
and variadic arguments into a va_format structure which is passed as
argument to the tracepoints of the class xhci_log_msg.

All the xhci_dbg() calls in xhci_address_device() are replaced
with calls to xhci_dbg_trace(). The functionality of xhci_dbg()
log messages was not removed though, but it is placed inside
xhci_dbg_trace().

This trace event aims to give the ability to the user or the
developper to isolate and trace the debug messages generated
when an Address Device Command is issued to xHC.
Signed-off-by: NXenia Ragiadakou <burzalodowa@gmail.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>

CONFIG_USB_XHCI_HCD_DEBUGGING option is used to enable
verbose debugging output for the xHCI host controller
driver.

In the current version of the xhci-hcd driver, this
option must be turned on, in order for the debugging
log messages to be displayed, and users may need to
recompile the linux kernel to obtain debugging
information that will help them track down problems.

This patch removes the above debug option to enable
debugging log messages at all times.
The aim of this is to rely on the debugfs and the
dynamic debugging feature for fine-grained management
of debugging messages and to not force users to set
the debug config option and compile the linux kernel
in order to have access in that information.

This patch, also, removes the XHCI_DEBUG symbol and the
functions dma_to_stream_ring(), xhci_test_radix_tree()
and xhci_event_ring_work() that are not useful anymore.
Signed-off-by: NXenia Ragiadakou <burzalodowa@gmail.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>

This patch replaces the calls to printk(KERN_DEBUG ...)
with either calls to xhci_dbg() or calls to pr_debug(),
depending on whether the xhci_hcd structure is available
at callsite, so that the correspoding debugging messages
are not enabled by default when CONFIG_DYNAMIC_DEBUG option
is set but rather can be enabled dynamically taking advantage
of the dynamic debugging feature.

Also, it adds a newline at the end of debugging messages in
case there is not, so that messages don't appear broken
when printed.
Signed-off-by: NXenia Ragiadakou <burzalodowa@gmail.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>

This patch replaces the calls to xhci_info() with calls to
xhci_dbg() and removes the unused xhci_info() definition
from xhci-hcd.

By replacing the xhci_info() with xhci_dbg(), the calls to
dev_info() are replaced with calls to dev_dbg() so that
their output can be dynamically controlled via the dynamic
debugging mechanism.
Signed-off-by: NXenia Ragiadakou <burzalodowa@gmail.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>

Add Device Tree match table to xhci-plat.c. Add DT bindings document.
Signed-off-by: NAl Cooper <alcooperx@gmail.com>
Cc: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Cc: Felipe Balbi <balbi@ti.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>

Prevent the USB core from suspending the HWA root hub since bus_suspend
and bus_resume are not yet supported.  Otherwise the PM system will chew
up CPU time constantly attempting to suspend and resume the root hub but
never succeeding.
Signed-off-by: NThomas Pugliese <thomas.pugliese@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Since commits 4005ad43 (EHCI: implement new semantics for
URB_ISO_ASAP) and c75c5ab5 (ALSA: USB: adjust for changed 3.8 USB
API) became widely distributed, people have been experiencing problems
with audio transfers.  The slightest underrun causes complete failure,
requiring the audio stream to be restarted.

It turns out that the current isochronous API doesn't handle underruns
in the best way.  The ALSA developers would much rather have transfers
that are submitted too late be accepted and complete in the normal
fashion, rather than being refused outright.

This patch implements the requested approach.  When an isochronous URB
submission is so late that all its scheduled slots have already
expired, a debugging message will be printed in the log and the URB
will be accepted as usual.  Assuming it was submitted by a completion
handler (which is normally the case), it will complete shortly
thereafter with all the usb_iso_packet_descriptor status fields marked
-EXDEV.

This fixes (for ehci-hcd)

	https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1191603

It should be applied to all kernels that include commit 4005ad43.
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
Tested-by: NMaksim Boyko <maksboyko@yandex.ru>
CC: Clemens Ladisch <clemens@ladisch.de>
CC: <stable@vger.kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The USB Embedded High-speed Host Electrical Test (EHSET) defines the
SINGLE_STEP_SET_FEATURE test as follows:

1) The host enumerates the test device with VID:0x1A0A, PID:0x0108
2) The host sends the SETUP stage of a GetDescriptor(Device)
3) The device ACKs the request
4) The host issues SOFs for 15 seconds allowing the test operator to
   raise the scope trigger just above the SOF voltage level
5) The host sends the IN packet
6) The device sends data in response, triggering the scope
7) The host sends an ACK in response to the data

This patch adds additional handling to the EHCI hub driver and allows
the EHSET driver to initiate this test mode by issuing a a SetFeature
request to the root hub with a Test Selector value of 0x06. From there
it mimics ehci_urb_enqueue() but separately submits QTDs for the
SETUP and DATA/STATUS stages in order to insert a delay in between.
Signed-off-by: NManu Gautam <mgautam@codeaurora.org>
Acked-by: NAlan Stern <stern@rowland.harvard.edu>
[jackp@codeaurora.org: imported from commit c2084930 on codeaurora.org;
 minor cleanup and updated author email]
Signed-off-by: NJack Pham <jackp@codeaurora.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

When CONFIG_USB_SUPPORT is not selected we get things like:

scripts/kconfig/mconf Kconfig
warning: (MIPS_SEAD3 && PMC_MSP && CPU_CAVIUM_OCTEON) selects USB_EHCI_BIG_ENDIAN_MMIO which has unmet direct dependencies (USB_SUPPORT && USB)

It is much cleaner to make the various system Kconfigs select
USB_EHCI_BIG_ENDIAN_MMIO rather than move the system config
information into USB's Kconfig, but the warnings are annoying.

Eliminate the warning by moving the definition of
USB_EHCI_BIG_ENDIAN_MMIO outside of all the Kconfig if statements.
While we are at it move USB_OHCI_BIG_ENDIAN_DESC,
USB_OHCI_BIG_ENDIAN_MMIO, USB_OHCI_LITTLE_ENDIAN and
USB_EHCI_BIG_ENDIAN_DESC too, as they could very well suffer similar
problems for other systems.

Get rid of the redundant "default n" in USB_OHCI_BIG_ENDIAN_DESC and
USB_OHCI_BIG_ENDIAN_MMIO
Signed-off-by: NDavid Daney <david.daney@cavium.com>
Acked-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This patch marks all xHCI controllers as no_sg_constraint
since xHCI supports building packet from discontinuous buffers.

Cc: Alan Stern <stern@rowland.harvard.edu>
Acked-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: NMing Lei <ming.lei@canonical.com>
Reviewed-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

All 4 transfer types can work well on EHCI HCD after switching to run
URB giveback in tasklet context, so mark all HCD drivers to support
it.

Also we don't need to release ehci->lock during URB giveback any more.

>From below test results on 3 machines(2 ARM and one x86), time
consumed by EHCI interrupt handler droped much without performance
loss.

1 test description
1.1 mass storage performance test:
- run below command 10 times and compute the average performance

    dd if=/dev/sdN iflag=direct of=/dev/null bs=200M count=1

- two usb mass storage device:
A: sandisk extreme USB 3.0 16G(used in test case 1 & case 2)
B: kingston DataTraveler G2 4GB(only used in test case 2)

1.2 uvc function test:
- run one simple capture program in the below link

   http://kernel.ubuntu.com/~ming/up/capture.c

- capture format 640*480 and results in High Bandwidth mode on the
uvc device: Z-Star 0x0ac8/0x3450

- on T410(x86) laptop, also use guvcview to watch video capture/playback

1.3 about test2 and test4
- both two devices involved are tested concurrently by above test items

1.4 how to compute irq time(the time consumed by ehci_irq)
- use trace points of irq:irq_handler_entry and irq:irq_handler_exit

1.5 kernel
3.10.0-rc3-next-20130528

1.6 test machines
Pandaboard A1: ARM CortexA9 dural core
Arndale board: ARM CortexA15 dural core
T410: i5 CPU 2.67GHz quad core

2 test result
2.1 test case1: single mass storage device performance test
--------------------------------------------------------------------
		upstream 		| patched
		perf(MB/s)+irq time(us)	| perf(MB/s)+irq time(us)
--------------------------------------------------------------------
Pandaboard A1:  25.280(avg:145,max:772)	| 25.540(avg:14, max:75)
Arndale board:  29.700(avg:33, max:129)	| 29.700(avg:10,  max:50)
T410: 		34.430(avg:17, max:154*)| 34.660(avg:12, max:155)
---------------------------------------------------------------------

2.2 test case2: two mass storage devices' performance test
--------------------------------------------------------------------
		upstream 			| patched
		perf(MB/s)+irq time(us)		| perf(MB/s)+irq time(us)
--------------------------------------------------------------------
Pandaboard A1:  15.840/15.580(avg:158,max:1216)	| 16.500/16.160(avg:15,max:139)
Arndale board:  17.370/16.220(avg:33 max:234)	| 17.480/16.200(avg:11, max:91)
T410: 		21.180/19.820(avg:18 max:160)	| 21.220/19.880(avg:11, max:149)
---------------------------------------------------------------------

2.3 test case3: one uvc streaming test
- uvc device works well(on x86, luvcview can be used too and has
same result with uvc capture)
--------------------------------------------------------------------
		upstream 		| patched
		irq time(us)		| irq time(us)
--------------------------------------------------------------------
Pandaboard A1:  (avg:445, max:873)	| (avg:33, max:44)
Arndale board:  (avg:316, max:630)	| (avg:20, max:27)
T410: 		(avg:39,  max:107)	| (avg:10, max:65)
---------------------------------------------------------------------

2.4 test case4: one uvc streaming plus one mass storage device test
--------------------------------------------------------------------
		upstream 		| patched
		perf(MB/s)+irq time(us)	| perf(MB/s)+irq time(us)
--------------------------------------------------------------------
Pandaboard A1:  20.340(avg:259,max:1704)| 20.390(avg:24, max:101)
Arndale board:  23.460(avg:124,max:726)	| 23.370(avg:15, max:52)
T410: 		28.520(avg:27, max:169)	| 28.630(avg:13, max:160)
---------------------------------------------------------------------

2.5 test case5: read single mass storage device with small transfer
- run below command 10 times and compute the average speed

 dd if=/dev/sdN iflag=direct of=/dev/null bs=4K count=4000

1), test device A:
--------------------------------------------------------------------
		upstream 		| patched
		perf(MB/s)+irq time(us)	| perf(MB/s)+irq time(us)
--------------------------------------------------------------------
Pandaboard A1:  6.5(avg:21, max:64)	| 6.5(avg:10, max:24)
Arndale board:  8.13(avg:12, max:23)	| 8.06(avg:7,  max:17)
T410: 		6.66(avg:13, max:131)   | 6.84(avg:11, max:149)
---------------------------------------------------------------------

2), test device B:
--------------------------------------------------------------------
		upstream 		| patched
		perf(MB/s)+irq time(us)	| perf(MB/s)+irq time(us)
--------------------------------------------------------------------
Pandaboard A1:  5.5(avg:21,max:43)	| 5.49(avg:10, max:24)
Arndale board:  5.9(avg:12, max:22)	| 5.9(avg:7, max:17)
T410: 		5.48(avg:13, max:155)	| 5.48(avg:7, max:140)
---------------------------------------------------------------------

* On T410, sometimes read ehci status register in ehci_irq takes more
than 100us, and the problem has been reported on the link:

	http://marc.info/?t=137065867300001&r=1&w=2Acked-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NMing Lei <ming.lei@canonical.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

ehci-hcd currently unlinks an interrupt QH when it becomes empty, that
is, after its last URB completes.  This works well because in almost
all cases, the completion handler for an interrupt URB resubmits the
URB; therefore the QH doesn't become empty and doesn't get unlinked.

When we start using tasklets for URB completion, this scheme won't work
as well.  The resubmission won't occur until the tasklet runs, which
will be some time after the completion is queued with the tasklet.
During that delay, the QH will be empty and so will be unlinked
unnecessarily.

To prevent this problem, this patch adds a 5-ms time delay before empty
interrupt QHs are unlinked.  Most often, during that time the interrupt
URB will be resubmitted and thus we can avoid unlinking the QH.
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NMing Lei <ming.lei@canonical.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The patch does the below improvement:

- think QH_STATE_COMPLETING as unlinking state since all URBs on the
endpoint should be in unlinking or unlinked when doing endpoint_disable()

- add "WARN_ON(!list_empty(&qh->qtd_list));" if qh->qh_state is
QH_STATE_LINKED because there shouldn't be any active transfer in qh

- when qh->qh_state is QH_STATE_LINKED, the QH(async or periodic)
should be in its corresponding list, so the search through the async
list isn't necessary.

- unlink periodic QH to speed up unlinking if the QH is in linked
state

Basically, only the last one is related with this patchset because
the assumption of "periodic qh self-unlinks on empty" isn't true
any more when we introduce unlink-wait for periodic qh.
Acked-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NMing Lei <ming.lei@canonical.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>