The assignement of EP transfer resources was not handled properly in the
dwc3 driver. Commit aebda618 ("usb: dwc3: Reset the transfer
resource index on SET_INTERFACE") previously fixed one aspect of this
where resources may be exhausted with multiple calls to SET_INTERFACE.
However, it introduced an issue where composite devices with multiple
interfaces can be assigned the same transfer resources for different
endpoints. This patch solves both issues.

The assignment of transfer resources cannot perfectly follow the data
book due to the fact that the controller driver does not have all
knowledge of the configuration in advance. It is given this information
piecemeal by the composite gadget framework after every
SET_CONFIGURATION and SET_INTERFACE. Trying to follow the databook
programming model in this scenario can cause errors. For two reasons:

1) The databook says to do DEPSTARTCFG for every SET_CONFIGURATION and
SET_INTERFACE (8.1.5). This is incorrect in the scenario of multiple
interfaces.

2) The databook does not mention doing more DEPXFERCFG for new endpoint
on alt setting (8.1.6).

The following simplified method is used instead:

All hardware endpoints can be assigned a transfer resource and this
setting will stay persistent until either a core reset or hibernation.
So whenever we do a DEPSTARTCFG(0) we can go ahead and do DEPXFERCFG for
every hardware endpoint as well. We are guaranteed that there are as
many transfer resources as endpoints.

This patch triggers off of the calling dwc3_gadget_start_config() for
EP0-out, which always happens first, and which should only happen in one
of the above conditions.

Fixes: aebda618 ("usb: dwc3: Reset the transfer resource index on SET_INTERFACE")
Cc: <stable@vger.kernel.org> # v3.2+
Reported-by: NRavi Babu <ravibabu@ti.com>
Signed-off-by: NJohn Youn <johnyoun@synopsys.com>
Signed-off-by: NFelipe Balbi <balbi@kernel.org>

This patch is needed in order to pass one test case
defined in the OTG Automated Compliance Test specification.

Specification location:
http://www.usb.org/developers/onthego/otgeh_compliance_plan_1_2.pdf

This test case uses PET Tool, and PET Tool is one USB hardware
equipment provided by MQP Electronics.

Test case id is 6.8.3 B-UUT Bypass Capacitance.

We must set this otg flag in order to be able to return OTG
descriptor during enumeration, otherwise this test case with
failed with below error: "Get OTG descriptor request stalled".
Signed-off-by: NJianqiang Tang <jianqiang.tang@intel.com>
Signed-off-by: NFelipe Balbi <balbi@kernel.org>

If the request->length is zero, a ZLP should already be sent due to that
and another ZLP is not needed to terminate the transfer.

Fixes: 04c03d10 ("usb: dwc3: gadget: handle request->zero")
Signed-off-by: NJohn Youn <johnyoun@synopsys.com>
Signed-off-by: NFelipe Balbi <balbi@ti.com>

instead of using:

	if (condition) {
		dev_WARN_ONCE(dev, true, "foo");
		return -EINVAL;
	}

let's use:

	if (dev_WARN_ONCE(dev, condition, "foo"))
		return -EINVAL;
Signed-off-by: NFelipe Balbi <balbi@ti.com>

So far, dwc3 has always missed request->zero
handling for every endpoint. Let's implement
that so we can handle cases where transfer must
be finished with a ZLP.

Note that dwc3 is a little special. Even though
we're dealing with a ZLP, we still need a buffer
of wMaxPacketSize bytes; to hide that detail from
every gadget driver, we have a preallocated buffer
of 1024 bytes (biggest bulk size) to use (and
share) among all endpoints.
Reported-by: NRavi B <ravibabu@ti.com>
Signed-off-by: NFelipe Balbi <balbi@ti.com>

It just ocurred to me that dwc3 already gives a
really hint of when a setup packet is pending and
that's the SETUP_PENDING TRB Status for EP0 IRQs.

Fix setup_packet_pending initialization based on
that. While at that, also make sure the comment in
gadget.c matches what code is doing.
Signed-off-by: NFelipe Balbi <balbi@ti.com>

In dwc3_cleanup_done_reqs() we expect that all
iterations of our while (1) loop will find a valid
struct dwc3_request *. In case we don't, we're
dumping a WARN_ON_ONCE() splat so that people report
the failure.

This patch is a simple cleanup converting:

	if (!req) {
		WARN_ON_ONCE(1);
		return 1;
	}

to:

	if (WARN_ON_ONCE(!req))
		return 1;

which is a little easier to read.
Signed-off-by: NFelipe Balbi <balbi@ti.com>

The last few dev_dbg() messages are converted to
tracepoints and we can finally ignore dev_dbg()
messages during debug sessions.
Signed-off-by: NFelipe Balbi <balbi@ti.com>

By moving our sanity checks our internal function
__dwc3_gadget_ep_queue() we can simplify the
externally visible API while also making sure that
callers of __dwc3_gadget_ep_queue() also make use of
the same checks.
Signed-off-by: NFelipe Balbi <balbi@ti.com>

Because interrupt endpoints usually transmit such
small amounts of data, it seems pointless to prestart
transfers and try to get speed improvements. This
patch also sorts out a problem with CDC ECM function
where its notification endpoint gets stuck in busy
state and we continuously issue Update Transfer
commands.

Fixes: 8a1a9c9e ("usb: dwc3: gadget: start transfer on XFER_COMPLETE")
Signed-off-by: NFelipe Balbi <balbi@ti.com>

In some SoCs, dwc3 is implemented as a USB2.0 only
core, meaning that it can't ever achieve SuperSpeed.

Currect driver always sets gadget.max_speed to
USB_SPEED_SUPER unconditionally. This can causes
issues to some Host stacks where the host will issue
a GetBOS() request and we will reply with a BOS
containing Superspeed Capability Descriptor.

At least Windows seems to be upset by this fact and
prints a warning that we should connect $this device
to another port.

[ balbi@ti.com : rewrote entire commit, including
source code comment to make a lot clearer what the
problem is ]

Cc: <stable@vger.kernel.org>
Signed-off-by: NBen McCauley <ben.mccauley@garmin.com>
Signed-off-by: NFelipe Balbi <balbi@ti.com>

This reverts commit 8f2c9544.

As it breaks g_ether on my Baytrail FFRD8 device. Everything starts out
fine, but after a bit of data has been transferred it just stops
flowing.

Note that I do get a bunch of these "NOHZ: local_softirq_pending 08"
when booting the machine, but I'm not really sure if they're related
to this problem.

Cc: Felipe Balbi <balbi@ti.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: linux-usb@vger.kernel.org
Cc: stable@vger.kernel.org
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NFelipe Balbi <balbi@ti.com>

This reverts commit 70f3a9ca.

That commit was causing a lockdep splat with g_ether and that
was interfering with proper functionality.
Signed-off-by: NFelipe Balbi <balbi@ti.com>

We *know* our threads executes with our IRQs
disabled. We really don't need to use the _irqsave()
variant of spin_lock().
Signed-off-by: NFelipe Balbi <balbi@ti.com>

Instead of limiting __dwc3_gadget_kick_transfer() to
Xfer Complete, we can try to issue Update Transfer
command from Xfer In Progress too.
Signed-off-by: NFelipe Balbi <balbi@ti.com>

If we get a Xfer Not Ready event with reason
"Transfer Active" it means endpoint is still
transferring data and we can use that to issue
update transfer for this particular endpoint
in case we have pending requests in our queue.
Signed-off-by: NFelipe Balbi <balbi@ti.com>

if by the time we get to XFER_COMPLETE we have
pending requests to be processed, instead of waiting
for a following XFER_NOT_READY, let's start the request
right away and, maybe, save the time of a few NAKs
due to lack of started transfers.
Signed-off-by: NFelipe Balbi <balbi@ti.com>

We shouldn't return -EBUSY, that's used only internally
when the core still has transfers in flight on a given
endpoint.

Also, combine the error reporting so that we don't have
to duplicate it.
Signed-off-by: NFelipe Balbi <balbi@ti.com>

Instead of clearing DWC3_PENDING_REQUEST when
we start transfer, let's do it when the request
is actually queued, that way we know for sure
that we're clearing in the right time.
Signed-off-by: NFelipe Balbi <balbi@ti.com>

In an attempt to make dwc3 slightly faster, let's
start usb_requests as soon as they come as that will
let us avoid a XFER_NOT_READY event and save a little
bit of time.
Signed-off-by: NFelipe Balbi <balbi@ti.com>

by moving trace_dwc3_ep_queue() from dwc3_gadget_ep_queue()
to __dwc3_gadget_ep_queue() after usb_request is properly
initialized, makes for a better output always showing a
request with 0 actual and -115 (-EINPROGRESS) status.
Signed-off-by: NFelipe Balbi <balbi@ti.com>

Using spin_lock() in hard irq handler is pointless
and causes a BUG() in RT (real-time) configuration
so get rid of it.

The reason it's pointless is because the driver is
basically accessing register which is, anyways,
atomic.
Signed-off-by: NRoger Quadros <rogerq@ti.com>
Signed-off-by: NFelipe Balbi <balbi@ti.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>

Add chained TRB support to ep0. Now TRB's can be chained just by
invoking _dwc3_ep0_start_trans_ with 'chain' parameter set to true.
Signed-off-by: NKishon Vijay Abraham I <kishon@ti.com>
Signed-off-by: NFelipe Balbi <balbi@ti.com>

We should only change endpoint names when we
actually manage to enable/disable it.
Signed-off-by: NFelipe Balbi <balbi@ti.com>

We have a "Enabling %s" trace when enabling an endpoint
but that message felt lonely without a matching
"Disabling %s". Add it.
Signed-off-by: NFelipe Balbi <balbi@ti.com>

In case of non-Isochronous transfers, we don't
want to clear DWC3_EP_BUSY flag until XferComplete
event. That's because XferInProgress was only enabled
so we can recycle TRBs and usb_requests quicker, but
there are still other pending requests being transferred.

In order to make sure we don't allow for another StartTransfer
command while the HW is still processing other transfers,
we must keep DWC3_EP_BUSY flag set and this what this patch
does.

Fixes: f3af3651 (usb: dwc3: gadget: always enable IOC on
	bulk/interrupt transfers)
Cc: <stable@vger.kernel.org> # v3.15+
Reported-by: Nsundeep subbaraya <sundeep.lkml@gmail.com>
Tested-by: Nsundeep subbaraya <sundeep.lkml@gmail.com>
Signed-off-by: NFelipe Balbi <balbi@ti.com>

We need to return error to caller if command is not sent to
controller succesfully.
Signed-off-by: NSubbaraya Sundeep Bhatta <sbhatta@xilinx.com>
Fixes: 72246da4 (usb: Introduce DesignWare USB3 DRD Driver)
Cc: <stable@vger.kernel.org>
Signed-off-by: NFelipe Balbi <balbi@ti.com>

We need to return error to caller if command is not sent to
controller succesfully.
Signed-off-by: NSubbaraya Sundeep Bhatta <sbhatta@xilinx.com>
Fixes: b09bb642 (usb: dwc3: gadget: implement Global Command support)
Cc: <stable@vger.kernel.org> #v3.5+
Signed-off-by: NFelipe Balbi <balbi@ti.com>

Now that we're using XFERINPROGRESS for all endpoint
types (except Control), we will *always* be completing
one TRB at a time, so it's safe to remove the loop
from dwc3_cleanup_done_reqs.
Signed-off-by: NFelipe Balbi <balbi@ti.com>

Delete private selfpowered variable, and use common one.
Signed-off-by: NPeter Chen <peter.chen@freescale.com>
Signed-off-by: NFelipe Balbi <balbi@ti.com>

commit 8e74475b (usb: dwc3: gadget: use udc-core's
reset notifier) added support for the new UDC core's
reset notifier to dwc3 but while at it, it removed
a spin_lock() from dwc3_reset_gadget() which might
cause an unbalanced spin_unlock() further down the line

Fixes: 8e74475b (usb: dwc3: gadget: use udc-core's reset notifier)
Cc: <stable@vger.kernel.org> # v3.19
Signed-off-by: NFelipe Balbi <balbi@ti.com>

By moving all dev_vdbg() to tracepoints, we
can finally get rid of dev_vdbg() usage from
dwc3.
Signed-off-by: NFelipe Balbi <balbi@ti.com>

if an unknown IRQ event is triggered, that means
the HW is really misbehaving. Instead of printing
a debug message, let's WARN() so users report
when that happens.
Signed-off-by: NFelipe Balbi <balbi@ti.com>

We already have both ret and dwc defined in this
same function.
Signed-off-by: NFelipe Balbi <balbi@ti.com>

DWC3 gadget sets up a pool of 32 TRBs for each EP during initialization. This
means, the max TRBs that can be submitted for an EP is fixed to 32. Since the
request queue for an EP is a linked list, any number of requests can be queued
to it by the gadget layer.  However, the dwc3 driver must not submit TRBs more
than the pool it has created for. This limit wasn't respected when SG was used
resulting in submitting more than the max TRBs, eventually leading to
non-transfer of the TRBs submitted over the max limit.

Root cause:
When SG is used, there are two loops iterating to prepare TRBs:
 - Outer loop over the request_list
 - Inner loop over the SG list
The code was missing break to get out of the outer loop.

Fixes: eeb720fb (usb: dwc3: gadget: add support for SG lists)
Cc: <stable@vger.kernel.org> # v3.9+
Signed-off-by: NAmit Virdi <amit.virdi@st.com>
Signed-off-by: NFelipe Balbi <balbi@ti.com>

When scatter gather (SG) is used, multiple TRBs are prepared from one DWC3
request (dwc3_request). So while preparing TRBs, the 'last' flag should be set
only when it is the last TRB being prepared from the last dwc3_request entry.

The current implementation uses list_is_last to check if the dwc3_request is the
last entry from the request_list. However, list_is_last returns false for the
last entry too. This is because, while preparing the first TRB from a request,
the function dwc3_prepare_one_trb modifies the request's next and prev pointers
while moving the URB to req_queued. Hence, list_is_last always returns false no
matter what.

The correct way is not to access the modified pointers of dwc3_request but to
use list_empty macro instead.

Fixes: e5ba5ec8 (usb: dwc3: gadget: fix scatter gather implementation)
Signed-off-by: NAmit Virdi <amit.virdi@st.com>
Cc: <stable@vger.kernel.org> # v3.9+
Signed-off-by: NFelipe Balbi <balbi@ti.com>

dwc3_gadget_init_hw_endpoints calls dwc3_alloc_trb_pool only if epnum is not
equal to 0 or 1. Hence, rechecking it in the called function is redundant.
Signed-off-by: NAmit Virdi <amit.virdi@st.com>
Signed-off-by: NFelipe Balbi <balbi@ti.com>

Fixed a typo in comments
Signed-off-by: NMickael Maison <mickael.maison@gmail.com>
Signed-off-by: NFelipe Balbi <balbi@ti.com>

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