Set the dma for chipidea from sysdev. This is inherited from its
parent node. Also, do not set dma mask for child as it is not required
now.
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NSriram Dash <sriram.dash@nxp.com>
Acked-by: NPeter Chen <peter.chen@nxp.com>
Signed-off-by: NMathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: NPeter Chen <peter.chen@nxp.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The CI_HDRC_CONTROLLER_STOPPED_EVENT may want to call sleeping
APIs similar to how _gadget_stop_activity() may. Let's drop the
lock across the event so that glue drivers can make sleeping
calls.

Cc: Peter Chen <peter.chen@nxp.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NStephen Boyd <stephen.boyd@linaro.org>
Signed-off-by: NPeter Chen <peter.chen@nxp.com>

We don't call hw_device_reset() with the ci->lock held, so it
doesn't seem like this lock here is protecting anything. Let's
just remove it. This allows us to call sleeping functions like
phy_init() from within the CI_HDRC_CONTROLLER_RESET_EVENT hook.
Acked-by: NPeter Chen <peter.chen@nxp.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NStephen Boyd <stephen.boyd@linaro.org>
Signed-off-by: NPeter Chen <peter.chen@nxp.com>

This can fix below dump when the lock is accessed at host
mode due to it is not initialized.

[   46.119638] INFO: trying to register non-static key.
[   46.124643] the code is fine but needs lockdep annotation.
[   46.130144] turning off the locking correctness validator.
[   46.135659] CPU: 0 PID: 690 Comm: cat Not tainted 4.9.0-rc3-00079-g4b75f1d #1210
[   46.143075] Hardware name: Freescale i.MX6 SoloX (Device Tree)
[   46.148923] Backtrace:
[   46.151448] [<c010c460>] (dump_backtrace) from [<c010c658>] (show_stack+0x18/0x1c)
[   46.159038]  r7:edf52000
[   46.161412]  r6:60000193
[   46.163967]  r5:00000000
[   46.165035]  r4:c0e25c2c

[   46.169109] [<c010c640>] (show_stack) from [<c03f58a4>] (dump_stack+0xb4/0xe8)
[   46.176362] [<c03f57f0>] (dump_stack) from [<c016d690>] (register_lock_class+0x4fc/0x56c)
[   46.184554]  r10:c0e25d24
[   46.187014]  r9:edf53e70
[   46.189569]  r8:c1642444
[   46.190637]  r7:ee9da024
[   46.193191]  r6:00000000
[   46.194258]  r5:00000000
[   46.196812]  r4:00000000
[   46.199185]  r3:00000001

[   46.203259] [<c016d194>] (register_lock_class) from [<c0171294>] (__lock_acquire+0x80/0x10f0)
[   46.211797]  r10:c0e25d24
[   46.214257]  r9:edf53e70
[   46.216813]  r8:ee9da024
[   46.217880]  r7:c1642444
[   46.220435]  r6:edcd1800
[   46.221502]  r5:60000193
[   46.224057]  r4:00000000

[   46.227953] [<c0171214>] (__lock_acquire) from [<c01726c0>] (lock_acquire+0x74/0x94)
[   46.235710]  r10:00000001
[   46.238169]  r9:edf53e70
[   46.240723]  r8:edf53f80
[   46.241790]  r7:00000001
[   46.244344]  r6:00000001
[   46.245412]  r5:60000193
[   46.247966]  r4:00000000

[   46.251866] [<c017264c>] (lock_acquire) from [<c096c8fc>] (_raw_spin_lock_irqsave+0x40/0x54)
[   46.260319]  r7:ee1c6a00
[   46.262691]  r6:c062a570
[   46.265247]  r5:20000113
[   46.266314]  r4:ee9da014

[   46.270393] [<c096c8bc>] (_raw_spin_lock_irqsave) from [<c062a570>] (ci_port_test_show+0x2c/0x70)
[   46.279280]  r6:eebd2000
[   46.281652]  r5:ee9da010
[   46.284207]  r4:ee9da014

[   46.286810] [<c062a544>] (ci_port_test_show) from [<c0248d04>] (seq_read+0x1ac/0x4f8)
[   46.294655]  r9:edf53e70
[   46.297028]  r8:edf53f80
[   46.299583]  r7:ee1c6a00
[   46.300650]  r6:00000001
[   46.303205]  r5:00000000
[   46.304273]  r4:eebd2000
[   46.306850] [<c0248b58>] (seq_read) from [<c039e864>] (full_proxy_read+0x54/0x6c)
[   46.314348]  r10:00000000
[   46.316808]  r9:c0a6ad30
[   46.319363]  r8:edf53f80
[   46.320430]  r7:00020000
[   46.322986]  r6:b6de3000
[   46.324053]  r5:ee1c6a00
[   46.326607]  r4:c0248b58

[   46.330505] [<c039e810>] (full_proxy_read) from [<c021ec98>] (__vfs_read+0x34/0x118)
[   46.338262]  r9:edf52000
[   46.340635]  r8:c0107fc4
[   46.343190]  r7:00020000
[   46.344257]  r6:edf53f80
[   46.346812]  r5:c039e810
[   46.347879]  r4:ee1c6a00
[   46.350447] [<c021ec64>] (__vfs_read) from [<c021fbd0>] (vfs_read+0x8c/0x11c)
[   46.357597]  r9:edf52000
[   46.359969]  r8:c0107fc4
[   46.362524]  r7:edf53f80
[   46.363592]  r6:b6de3000
[   46.366147]  r5:ee1c6a00
[   46.367214]  r4:00020000
[   46.369782] [<c021fb44>] (vfs_read) from [<c0220a4c>] (SyS_read+0x4c/0xa8)
[   46.376672]  r8:c0107fc4
[   46.379045]  r7:00020000
[   46.381600]  r6:b6de3000
[   46.382667]  r5:ee1c6a00
[   46.385222]  r4:ee1c6a00

[   46.387817] [<c0220a00>] (SyS_read) from [<c0107e20>] (ret_fast_syscall+0x0/0x1c)
[   46.395314]  r7:00000003
[   46.397687]  r6:b6de3000
[   46.400243]  r5:00020000
[   46.401310]  r4:00020000

Cc: <stable@vger.kernel.org>
Fixes: 26c696c6 ("USB: Chipidea: rename struct
	       	ci13xxx variables from udc to ci")
Signed-off-by: NPeter Chen <peter.chen@nxp.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The DMA descriptors are little endian, and we do a pretty good
job of handling them with the proper le32_to_cpu() markings, but
we don't actually mark them as __le32. This means checkers like
sparse can't easily find new bugs. Let's mark the members of
structures properly and fix the few places where we're missing
conversions.

Cc: Peter Chen <peter.chen@nxp.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NStephen Boyd <stephen.boyd@linaro.org>
Signed-off-by: NPeter Chen <peter.chen@nxp.com>

Now that usb_endpoint_maxp() only returns the lowest
11 bits from wMaxPacketSize, we can remove the &
operation from this driver.

Cc: Peter Chen <Peter.Chen@nxp.com>
Cc: <linux-usb@vger.kernel.org>
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

We have introduced a helper to calculate multiplier
value from wMaxPacketSize. Start using it.
Acked-by: NPeter Chen <Peter.Chen@nxp.com>
Cc: <linux-usb@vger.kernel.org>
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

According to Documentation/CodingStyle:

"The preferred form for passing a size of a struct is the following:

	p = kmalloc(sizeof(*p), ...);
"
, so do as suggested to improve readability.
Signed-off-by: NFabio Estevam <fabio.estevam@nxp.com>
Signed-off-by: NPeter Chen <peter.chen@nxp.com>

No need to split the dma_pool_zalloc() line into two as it can
perfectly fit into a single line.
Signed-off-by: NFabio Estevam <fabio.estevam@nxp.com>
Signed-off-by: NPeter Chen <peter.chen@nxp.com>

We can make the code simpler by using dma_pool_zalloc() instead
of calling dma_pool_alloc() and then a memset().
Signed-off-by: NFabio Estevam <fabio.estevam@nxp.com>
Signed-off-by: NPeter Chen <peter.chen@nxp.com>

This driver make assumptions about the value of the direction flags.
So better use them in comparisons to improve the readability.
Signed-off-by: NStefan Wahren <stefan.wahren@i2se.com>
Signed-off-by: NPeter Chen <peter.chen@nxp.com>

The endpoint fifo is already flushed in _ep_nuke so there
is no need to flush it twice.
Signed-off-by: NStefan Wahren <stefan.wahren@i2se.com>
Signed-off-by: NPeter Chen <peter.chen@nxp.com>

Since there should be a write barrier before every call of
hw_ep_prime we could move it into hw_ep_prime.
Signed-off-by: NStefan Wahren <stefan.wahren@i2se.com>
Signed-off-by: NPeter Chen <peter.chen@nxp.com>

Problems with the signal integrity of the high speed USB data lines or
noise on reference ground lines can cause the i.MX6 USB controller to
violate USB specs and exhibit unexpected behavior.

It was observed that USBi_UI interrupts were triggered first and when
isr_setup_status_phase was called, ci->status was NULL, which lead to a
NULL pointer dereference kernel panic.

This patch fixes the kernel panic, emits a warning once and returns
-EPIPE to halt the device and let the host get stalled.
It also adds a comment to point people, who are experiencing this issue,
to their USB hardware design.

Cc: <stable@vger.kernel.org> #4.1+
Signed-off-by: NClemens Gruber <clemens.gruber@pqgruber.com>
Signed-off-by: NPeter Chen <peter.chen@nxp.com>

When the controller is configured to be dual role and it's in host mode,
if bind udc and gadgt driver, those gadget operations will do gadget
disconnect and finally pull down DP line, which will break host function.

Cc: <stable@vger.kernel.org> # 4.1+
Signed-off-by: NLi Jun <jun.li@nxp.com>
Signed-off-by: NPeter Chen <peter.chen@nxp.com>

Since gadget driver will handle this request, so controller driver bypass
it.
Acked-by: NPeter Chen <peter.chen@freescale.com>
Signed-off-by: NLi Jun <jun.li@nxp.com>
Signed-off-by: NFelipe Balbi <balbi@kernel.org>

retval is assigned to be -EOVERFLOW but is overwritten later before
it's used, remove this unused value assignment.
Signed-off-by: NLi Jun <jun.li@nxp.com>
Signed-off-by: NPeter Chen <peter.chen@nxp.com>

Since we need to mount debugfs to show/store the things we
want to debug, it is duplicated to add another configuration
to enable it. Meanwhile, with CONFIG_USB_CHIPIDEA_DEBUG,
we can't support chipidea debugfs at runtime.
Signed-off-by: NPeter Chen <peter.chen@freescale.com>
Cc: Jun Li <jun.li@freescale.com>

_hardware_enqueue() didn't check for errors when using
add_td_to_list() which can fail if dma_pool_alloc fails, thus
causing a kernel panic when lastnode->ptr is NULL.
Signed-off-by: NFelipe F. Tonello <eu@felipetonello.com>
Signed-off-by: NPeter Chen <peter.chen@freescale.com>

Update comments to reflect current state of functions.
Signed-off-by: NFelipe F. Tonello <eu@felipetonello.com>
Signed-off-by: NPeter Chen <peter.chen@freescale.com>

replace dma_pool_alloc and memset with a single call to dma_pool_zalloc
Signed-off-by: NSaurabh Sengar <saurabh.truth@gmail.com>
Acked-by: NPeter Chen <peter.chen@freescale.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This patch is to support load and unload gadget driver in full OTG mode.
Signed-off-by: NLi Jun <jun.li@freescale.com>
Signed-off-by: NPeter Chen <peter.chen@freescale.com>
Tested-by: NJiada Wang <jiada_wang@mentor.com>
Cc: <stable@vger.kernel.org> #v4.0+

According to spec, there are functional and protocol stalls.

For functional stall, it is for bulk and interrupt endpoints,
below are cases for it:
- Host sends SET_FEATURE request for Set-Halt, the udc driver
needs to set stall, and return true unconditionally.
- The gadget driver may call usb_ep_set_halt to stall certain
endpoints, if there is a transfer in pending, the udc driver
should not set stall, and return -EAGAIN accordingly.
These two kinds of stall need to be cleared by host using CLEAR_FEATURE
request (Clear-Halt).

For protocol stall, it is for control endpoint, this stall will
be set if the control request has failed. This stall will be
cleared by next setup request (hardware will do it).

It fixed usbtest (drivers/usb/misc/usbtest.c) Test 13 "set/clear halt"
test failure, meanwhile, this change has been verified by
USB2 CV Compliance Test and MSC Tests.

Cc: <stable@vger.kernel.org> #3.10+
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Felipe Balbi <balbi@ti.com>
Signed-off-by: NPeter Chen <peter.chen@freescale.com>

The zero-length packet is the sendor tells the receiver that there
is no more data, so it is only needed at the TX side.
Signed-off-by: NPeter Chen <peter.chen@freescale.com>

We can support USB OTG 1.3 USB_DEVICE_A_HNP_SUPPORT request when
the driver supports OTG FSM mode.
Signed-off-by: NPeter Chen <peter.chen@freescale.com>

Convert endpoint configuration to new capabilities model.
Signed-off-by: NRobert Baldyga <r.baldyga@samsung.com>
Signed-off-by: NFelipe Balbi <balbi@ti.com>

Since some chipidea based controller is not otg capable, add ci->is_otg
condition when setting is_otg flag for gadget.
Signed-off-by: NLi Jun <jun.li@freescale.com>
Reviewed-by: NRoger Quadros <rogerq@ti.com>
Acked-by: NPeter Chen <peter.chen@freescale.com>
Signed-off-by: NFelipe Balbi <balbi@ti.com>

Init and update otg capabilities by DT, set gadget's otg capabilities
accordingly.
Acked-by: NPeter Chen <peter.chen@freescale.com>
Reviewed-by: NRoger Quadros <rogerq@ti.com>
Signed-off-by: NLi Jun <jun.li@freescale.com>
Signed-off-by: NFelipe Balbi <balbi@ti.com>

By pass pullup DP in OTG fsm mode when do gadget connect, to let it handled
by OTG state machine.

This patch can fix the problem you found with my HNP polling patchset after
below 3 patches introduced:
467a78c8 usb: chipidea: udc: apply new usb_udc_vbus_handler interface
628ef0d2 usb: udc: add usb_udc_vbus_handler
dfea9c94 usb: udc: store usb_udc pointer in struct usb_gadget

Problem:
- Connect USB cable and MicroAB cable between two boards
- Boot up two boards
- load g_mass_storage at B-device side, the enumeration will success,
and A will see a usb mass-storage device
- load g_mass_storage at A-device side, the problem has occurred, the
connection will be lost at the beginning, then connect again.

This patch is based on
commit eff933c1d3a2e046492b3dfc86db813856553a29
(chipidea: pci: make it depends on NOP_USB_XCEIV)
on branch peter-usb-dev of
git://git.kernel.org/pub/scm/linux/kernel/git/peter.chen/usb.gitSigned-off-by: NLi Jun <jun.li@freescale.com>
Signed-off-by: NPeter Chen <peter.chen@freescale.com>

It can move all pullup/pulldown operation control to udc-core
through usb_gadget_connect/usb_gadget_disconnect according to
vbus status.
Signed-off-by: NPeter Chen <peter.chen@freescale.com>
Signed-off-by: NFelipe Balbi <balbi@ti.com>

At chipidea revision 2.40a, there is a below errata:

9000531823  B2-Medium  Adding a dTD to a Primed Endpoint May Not Get Recognized

Title: Adding a dTD to a Primed Endpoint May Not Get Recognized

Impacted Configuration: All device mode configurations.

Description:
There is an issue with the add dTD tripwire semaphore (ATDTW bit in USBCMD register)
that can cause the controller to ignore a dTD that is added to a primed endpoint.
When this happens, the software can read the tripwire bit and the status bit at '1'
even though the endpoint is unprimed.

After executing a dTD, the device controller endpoint state machine executes a final
read of the dTD terminate bit to check if the application added a dTD to the linked
list at the last moment. This read is done in the finpkt_read_latest_next_td (44) state.
After the read is performed, if the terminate bit is still set, the state machine moves
to unprime the endpoint. The decision to unprime the endpoint is done in the
checkqh_decision (59) state, based on the value of the terminate bit.
Before reaching the checkqh_decision state, the state machine traverses the
writeqhtd_status (57), writeqh_status (56), and release_prime_mask (42) states.
As shown in the waveform, the ep_addtd_tripwire_clr signal is not set to clear
the tripwire bit in these states.

Workaround:
The software must implement a periodic poll cycle, and check for each dTD
pending on execution (Active = 1), if the enpoint is primed. It can do this by reading
the corresponding bits in the ENDPTPRIME and ENDPTSTAT registers. If these bits are
read at 0, the software needs to re-prime the endpoint by writing 1 to the corresponding
bit in the ENDPTPRIME register. This can be done for every microframe, every frame or
with a larger interval, depending on the urgency of transfer execution for the application.
Tested-by: NStefan Agner <stefan@agner.ch>
Signed-off-by: NPeter Chen <peter.chen@freescale.com>
Signed-off-by: NSanchayan Maity <maitysanchayan@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Some gadget driver (like uac1) will try to enable endpoint again even
the ep is not empty, it will cause the ep reset again and may affect
the dTD list which has already queued.

It returns -EBUSY immediately, and indicate the endpoint is in use.
In this way, the ep's behavior will not be affected, and the gadget
driver is also notified.

Cc: Xuebing Wang <xbing6@gmail.com>
Signed-off-by: NPeter Chen <peter.chen@freescale.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This patch adds response to a_alt_hnp_support set feature request from legacy
A device, that is, B-device can provide a message to the user indicating that
the user needs to connect the B-device to an alternate port on the A-device.
A device sets this feature indicates to the B-device that it is connected
to an A-device port that is not capable of HNP, but that the A-device does have
an alternate port that is capable of HNP.

[Peter]
Without this patch, the OTG B device can't be enumerated on
non-HNP port at A device, see below log:
[    2.287464] usb 1-1: Dual-Role OTG device on non-HNP port
[    2.293105] usb 1-1: can't set HNP mode: -32
[    2.417422] usb 1-1: new high-speed USB device number 4 using ci_hdrc
[    2.460635] usb 1-1: Dual-Role OTG device on non-HNP port
[    2.466424] usb 1-1: can't set HNP mode: -32
[    2.587464] usb 1-1: new high-speed USB device number 5 using ci_hdrc
[    2.630649] usb 1-1: Dual-Role OTG device on non-HNP port
[    2.636436] usb 1-1: can't set HNP mode: -32
[    2.641003] usb usb1-port1: unable to enumerate USB device

Cc: stable <stable@vger.kernel.org>
Acked-by: NPeter Chen <peter.chen@freescale.com>
Signed-off-by: NLi Jun <b47624@freescale.com>
Signed-off-by: NPeter Chen <peter.chen@freescale.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The gadget power property will be used at get_status request.
Signed-off-by: NPeter Chen <peter.chen@freescale.com>
Signed-off-by: NFelipe Balbi <balbi@ti.com>

The hw_device_reset is dedicated to be used at device mode initializaiton,
so delete the parameter 'mode'. For host driver, the ehci driver will
handle all things.
Signed-off-by: NPeter Chen <peter.chen@freescale.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Replace usb_gadget_driver's disconnect with udc-core's reset notifier at
bus reset handler.
Signed-off-by: NPeter Chen <peter.chen@freescale.com>
Signed-off-by: NFelipe Balbi <balbi@ti.com>

This patch modify the generic code handling PHYs to allow them to be
supplied from the drivers. This adds checks to ensure no PHY was already
there when looking for one in the generic code. This also makes sure we
do not modify its state in the generic HCD functions, it was provided by
the driver.
Signed-off-by: NAntoine Tenart <antoine.tenart@free-electrons.com>
Acked-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NFelipe Balbi <balbi@ti.com>

now that no UDC driver relies on the extra
'driver' argument to ->udc_stop(), we can
safely remove it.

This commit is based on previous work by
Robert Baldyga <r.baldyga@samsung.com> which
can be found at [1]; however that patch turned
out to have a high probability of regressing
many UDC drivers because of a blind search & replace
s/driver/$udc->driver/ which caused the 'driver'
argument to stop_activity() to be a valid non-NULL
pointer when it should be NULL, thus causing UDCs
to mistakenly call gadget driver's ->disconnect()
callback.

[1] http://markmail.org/message/x5zneg4xea4zntabAcked-by: NPeter Chen <peter.chen@freescale.com>
Signed-off-by: NFelipe Balbi <balbi@ti.com>

Use the recently introduced usb_gadget_giveback_request() in favor of
direct invocation of the completion routine.

All places in drivers/usb/ matching "[-.]complete(" were replaced with a
call to usb_gadget_giveback_request(). This was compile-tested with all
ARM drivers enabled and runtime-tested for musb.
Signed-off-by: NMichal Sojka <sojka@merica.cz>
Acked-by: NFelipe Balbi <balbi@ti.com>
Tested-by: NFelipe Balbi <balbi@ti.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

There are 2 methods for ZLP (zero-length packet) generation:
1) In software
2) Automatic generation by device controller

1) is implemented in UDC driver and it attaches ZLP to IN packet if
   descriptor->size < wLength
2) can be enabled/disabled by setting ZLT bit in the QH

When gadget ffs is connected to ubuntu host, the host sends
get descriptor request and wLength in setup packet is 255 while the
size of descriptor which will be sent by gadget in IN packet is
64 byte. So the composite driver sets req->zero = 1.
In UDC driver following code will be executed then

        if (hwreq->req.zero && hwreq->req.length
            && (hwreq->req.length % hwep->ep.maxpacket == 0))
                add_td_to_list(hwep, hwreq, 0);

Case-A:
So in case of ubuntu host, UDC driver will attach a ZLP to the IN packet.
ubuntu host will request 255 byte in IN request, gadget will send 64 byte
with ZLP and host will come to know that there is no more data.
But hold on, by default ZLT=0 for endpoint 0 so hardware also tries to
automatically generate the ZLP which blocks enumeration for ~6 seconds due
to endpoint 0 STALL, NAKs are sent to host for any requests (OUT/PING)

Case-B:
In case when gadget ffs is connected to Apple device, Apple device sends
setup packet with wLength=64. So descriptor->size = 64 and wLength=64
therefore req->zero = 0 and UDC driver will not attach any ZLP to the
IN packet. Apple device requests 64 bytes, gets 64 bytes and doesn't
further request for IN data. But ZLT=0 by default for endpoint 0 so
hardware tries to automatically generate the ZLP which blocks enumeration
for ~6 seconds due to endpoint 0 STALL, NAKs are sent to host for any
requests (OUT/PING)

According to USB2.0 specs:

    8.5.3.2 Variable-length Data Stage
    A control pipe may have a variable-length data phase in which the
    host requests more data than is contained in the specified data
    structure. When all of the data structure is returned to the host,
    the function should indicate that the Data stage is ended by
    returning a packet that is shorter than the MaxPacketSize for the
    pipe. If the data structure is an exact multiple of wMaxPacketSize
    for the pipe, the function will return a zero-length packet to indicate
    the end of the Data stage.

In Case-A mentioned above:
If we disable software ZLP generation & ZLT=0 for endpoint 0 OR if software
ZLP generation is not disabled but we set ZLT=1 for endpoint 0 then
enumeration doesn't block for 6 seconds.

In Case-B mentioned above:
If we disable software ZLP generation & ZLT=0 for endpoint then enumeration
still blocks due to ZLP automatically generated by hardware and host not needing
it. But if we keep software ZLP generation enabled but we set ZLT=1 for
endpoint 0 then enumeration doesn't block for 6 seconds.

So the proper solution for this issue seems to disable automatic ZLP generation
by hardware (i.e by setting ZLT=1 for endpoint 0) and let software (UDC driver)
handle the ZLP generation based on req->zero field.

Cc: stable@vger.kernel.org
Signed-off-by: NAbbas Raza <Abbas_Raza@mentor.com>
Signed-off-by: NPeter Chen <peter.chen@freescale.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>