Commit Graph

345 Commits

Author SHA1 Message Date
Felipe Balbi
6b9018d4c1 usb: dwc3: gadget: set PCM1 field of isochronous-first TRBs
In case of High-Speed, High-Bandwidth endpoints, we
need to tell DWC3 that we have more than one packet
per interval. We do that by setting PCM1 field of
Isochronous-First TRB.

Cc: <stable@vger.kernel.org>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
2016-10-31 11:15:34 +02:00
Christophe JAILLET
51fbc7c06c usb: dwc3: Fix size used in dma_free_coherent()
In commit 2abd9d5fa6 ("usb: dwc3: ep0: Add chained TRB support"), the
size of the memory allocated with 'dma_alloc_coherent()' has been modified
but the corresponding calls to 'dma_free_coherent()' have not been updated
accordingly.

This has been spotted with coccinelle, using the following script:
////////////////////
@r@
expression x0, x1, y0, y1, z0, z1, t0, t1, ret;
@@

*   ret = dma_alloc_coherent(x0, y0, z0, t0);
    ...
*   dma_free_coherent(x1, y1, ret, t1);

@script:python@
y0 << r.y0;
y1 << r.y1;

@@
if y1.find(y0) == -1:
 print "WARNING: sizes look different:  '%s'   vs   '%s'" % (y0, y1)
////////////////////

Fixes: 2abd9d5fa6 ("usb: dwc3: ep0: Add chained TRB support")

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
2016-10-17 12:35:48 +03:00
Felipe Balbi
d889c23ce4 usb: dwc3: gadget: never pre-start Isochronous endpoints
We cannot pre-start isochronous endpoints because we
rely on the micro-frame number passed via
XferNotReady command for proper Isochronous
scheduling.

Fixes: 08a36b5438 ("usb: dwc3: gadget: simplify __dwc3_gadget_ep_queue()")
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
2016-10-17 11:14:00 +03:00
Felipe Balbi
a9c3ca5fae usb: dwc3: gadget: properly account queued requests
Some requests could be accounted for multiple
times. Let's fix that so each and every requests is
accounted for only once.

Cc: <stable@vger.kernel.org> # v4.8
Fixes: 55a0237f8f ("usb: dwc3: gadget: use allocated/queued reqs for LST bit")
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
2016-10-17 11:14:00 +03:00
Greg Kroah-Hartman
8152263748 usb: patches for v4.9 merge window
This time around we have 92 non-merge commits. Most
 of the changes are in drivers/usb/gadget (40.3%)
 with drivers/usb/gadget/function being the most
 active directory (27.2%).
 
 As for UDC drivers, only dwc3 (26.5%) and dwc2
 (12.7%) have really been active.
 
 The most important changes for dwc3 are better
 support for scatterlist and, again, throughput
 improvements. While on dwc2 got some minor stability
 fixes related to soft reset and FIFO usage.
 
 Felipe Tonello has done some good work fixing up our
 f_midi gadget and Tal Shorer has implemented a nice
 API change for our ULPI bus.
 
 Apart from these, we have our usual set of
 non-critical fixes, spelling fixes, build warning
 fixes, etc.
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Merge tag 'usb-for-v4.9' of git://git.kernel.org/pub/scm/linux/kernel/git/balbi/usb into usb-next

Felipe writes:

usb: patches for v4.9 merge window

This time around we have 92 non-merge commits. Most
of the changes are in drivers/usb/gadget (40.3%)
with drivers/usb/gadget/function being the most
active directory (27.2%).

As for UDC drivers, only dwc3 (26.5%) and dwc2
(12.7%) have really been active.

The most important changes for dwc3 are better
support for scatterlist and, again, throughput
improvements. While on dwc2 got some minor stability
fixes related to soft reset and FIFO usage.

Felipe Tonello has done some good work fixing up our
f_midi gadget and Tal Shorer has implemented a nice
API change for our ULPI bus.

Apart from these, we have our usual set of
non-critical fixes, spelling fixes, build warning
fixes, etc.
2016-09-14 20:37:50 +02:00
Lu Baolu
5e6c88d28c usb: dwc3: fix Clear Stall EP command failure
Commit 50c763f8c1 ("usb: dwc3: Set the ClearPendIN bit on Clear
Stall EP command") sets ClearPendIN bit for all IN endpoints of
v2.60a+ cores. This causes ClearStall command fails on 2.60+ cores
operating in HighSpeed mode.

In page 539 of 2.60a specification:

"When issuing Clear Stall command for IN endpoints in SuperSpeed
mode, the software must set the "ClearPendIN" bit to '1' to
clear any pending IN transcations, so that the device does not
expect any ACK TP from the host for the data sent earlier."

It's obvious that we only need to apply this rule to those IN
endpoints that currently operating in SuperSpeed mode.

Fixes: 50c763f8c1 ("usb: dwc3: Set the ClearPendIN bit on Clear Stall EP command")
Cc: <stable@vger.kernel.org> # v4.7+
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
2016-09-12 10:05:55 +03:00
Arnd Bergmann
d6e10bf2ba usb: dwc3: avoid -Wmaybe-uninitialized warning
Cleaning up the loop in dwc3_cleanup_done_reqs() introduced a
gcc warning if built with "-Wmaybe-uninitialized":

drivers/usb/dwc3/gadget.c: In function 'dwc3_endpoint_transfer_complete':
drivers/usb/dwc3/gadget.c:2015:9: 'trb' may be used uninitialized in this function [-Wmaybe-uninitialized]

I believe it is a false positive and we always have a valid 'trb'
pointer at the end of the function, but neither I nor the compiler
are able to prove that.

This works around the warning by computing a flag earlier in the function
when it's guaranteed to be valid, which tells the compiler that it's
safe and makes it easier to understand to me.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Fixes: 31162af447 ("usb: dwc3: gadget: avoid while (1) loop on completion")
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
2016-09-09 14:56:06 +03:00
John Youn
9d7aba7786 Revert "usb: dwc3: gadget: always decrement by 1"
This reverts commit 6f8245b4e3 ("usb: dwc3: gadget: always decrement
by 1").

We can't always decrement this value.

We should decrement only if the calculation of free slots results in a
LINK TRB being among one of the free slots (dequeue < enqueue).

Otherwise, if the LINK TRB is not among the free slots then it should
not be decremented.

Signed-off-by: John Youn <johnyoun@synopsys.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
2016-09-05 13:39:23 +03:00
Felipe Balbi
6f8245b4e3 usb: dwc3: gadget: always decrement by 1
We need to decrement in both cases (enq > deq and
enq < deq)

Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
2016-08-25 12:30:27 +03:00
Felipe Balbi
594e121f25 usb: dwc3: gadget: stop kicking if we run out of space
In case our TRB ring is full, we can avoid trying to
kick transfers which won't start and just add requests
to the queue.

Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
2016-08-25 12:13:21 +03:00
Felipe Balbi
7ae7df4982 usb: dwc3: gadget: abolish trbs_left
Instead, we can always rely on dwc3_calc_trbs_left()
directly.

Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
2016-08-25 12:13:20 +03:00
John Youn
06281d460f usb: dwc3: Add ENDXFER command polling
ENDXFER polling is available on version 3.10a and later of the
DWC_usb3 (USB 3.0) controller. With this feature, the software can poll
the CMDACT bit in the DEPCMD register after issuing an ENDXFER command.
This feature is enabled by writing GUCTL2[14].

This feature is NOT available on the DWC_usb31 (USB 3.1) IP.

Signed-off-by: John Youn <johnyoun@synopsys.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
2016-08-25 12:13:19 +03:00
Felipe Balbi
dc55c67e9c usb: dwc3: gadget: improve increment request->actual
No functional changes, just a slight cosmetic
change.

Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
2016-08-25 12:13:06 +03:00
Felipe Balbi
f99f53f24d usb: dwc3: gadget: remove condition that never happens
We don't use LST bit anymore, so this condition will
never trigger.

Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
2016-08-25 12:13:06 +03:00
Felipe Balbi
1f512119a0 usb: dwc3: gadget: add remaining sg entries to ring
Upon transfer completion after a full ring, let's
add more TRBs to our ring in order to complete our
request successfully.

Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
2016-08-25 12:12:58 +03:00
Felipe Balbi
2c78c0295f usb: dwc3: gadget: interrupt on ring full too
If the ring is full and we are processing a big
sglist, then let's interrupt so we can, later, add
more TRBs to the ring.

Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
2016-08-22 10:45:37 +03:00
Felipe Balbi
31162af447 usb: dwc3: gadget: avoid while (1) loop on completion
We know that we have to iterate over the list of
started requests. Instead of looping forever, we can
rely on list_for_each_entry(). Likewise, instead of
a do {} while loop over all, maybe available,
scatterlist entries, we can detect if $this request
uses scatterlist and rely on for_each_sg().

This makes the code easier to follow while making
sure that we will *always* break out of the loop.

Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
2016-08-22 10:45:37 +03:00
Felipe Balbi
08a36b5438 usb: dwc3: gadget: simplify __dwc3_gadget_ep_queue()
Many of the comments in that function are really
outdated and don't match what the driver is
doing. Moreover, recent patches combined programming
model for all non-control endpoints, this gives us
an opportunity to get rid of our special cases in
__dwc3_gadget_ep_queue().

Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
2016-08-22 10:45:37 +03:00
Felipe Balbi
45438a0cd9 usb: dwc3: gadget: simplify dwc3_ep_prev_trb()
We always need to decrement our index by at least
one. Simplify the implementation by using a
temporary local variable and making sure that we
will always decrement one extra if tmp == 0.

Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
2016-08-22 10:45:37 +03:00
Felipe Balbi
737f1ae255 usb: dwc3: gadget: increment dequeue pointer on completion
Instead of waiting until giveback before
incrementing the dequeue pointer, we can increment
it from dwc3_cleanup_done_reqs(), that way we avoid
an extra loop over all TRBs during giveback.

While at that, also avoid using req->first_trb_index
as that's completely unnecessary. A follow-up patch
will clean up further uses of that and remove the
field altogether.

Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
2016-08-22 10:45:37 +03:00
Felipe Balbi
4bc48c9747 usb: dwc3: gadget: retire LST bit completely
The only endpoint which actually requires LST bit
and XferComplete is ep0/1. Let's save some time by
completely removing LST bit support and
XferComplete.

This simplifies and consolidates endpoint handling
for all other 3 transfer types while also avoiding
extra interrupts.

Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
2016-08-22 10:45:37 +03:00
Nicolas Saenz Julienne
d6011f6fc2 usb: dwc3: gadget: don't rely on jiffies while holding spinlock
__dwc3_gadget_wakeup() is called while holding a spinlock, then depends on
jiffies in order to timeout while polling the USB core for a link state
update. In the case the wakeup failed, the timeout will never happen and
will also cause the cpu to stall until rcu_preempt kicks in.

This switches to a "decrement variable and wait" timeout scheme.

Signed-off-by: Nicolas Saenz Julienne <nicolassaenzj@gmail.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
2016-08-22 10:45:13 +03:00
Felipe Balbi
a0ad85ae86 usb: dwc3: gadget: stop processing on HWO set
stop consuming TRBs when we reach one with HWO bit
already set. This will prevent us from prematurely
retiring a TRB.

Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
2016-08-11 15:09:48 +03:00
Janusz Dziedzic
79d17482a4 usb: dwc3: don't set last bit for ISOC endpoints
According to Synopsys Databook 2.60a, section 8.3.4,
it's stated that:

	The LST bit should be set to 0 (isochronous
	transfers normally continue until the
	endpoint is removed entirely, at which time
	an End Transfer command is used to stop the
	transfer).

This patch makes sure that detail is observed and
fixes a regression with Android Audio playback
caused by recent changes to DWC3 gadget.

Signed-off-by: Janusz Dziedzic <januszx.dziedzic@linux.intel.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
2016-08-11 15:09:48 +03:00
Felipe Balbi
7c705dfe2e usb: dwc3: gadget: always cleanup all TRBs
If we stop earlier due to short packet, we will
not be able to giveback all TRBs.

Cc: <stable@vger.kernel.org>
Cc: Brian E Rogers <brian.e.rogers@intel.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
2016-08-10 14:15:57 +03:00
Felipe Balbi
e5b36ae2f8 usb: dwc3: gadget: fix for short pkts during chained xfers
DWC3 has one interesting peculiarity with chained
transfers. If we setup N chained transfers and we
get a short packet before processing all N TRBs,
DWC3 will (conditionally) issue a XferComplete or
XferInProgress event and retire all TRBs from the
one which got a short packet to the last without
clearing their HWO bits.

This means SW must clear HWO bit manually, which
this patch is doing.

Cc: <stable@vger.kernel.org>
Cc: Brian E Rogers <brian.e.rogers@intel.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
2016-08-10 14:15:57 +03:00
Felipe Balbi
c7de573471 usb: dwc3: gadget: increment request->actual once
When using SG lists, we would end up setting
request->actual to:

	num_mapped_sgs * (request->length - count)

Let's fix that up by incrementing request->actual
only once.

Cc: <stable@vger.kernel.org>
Reported-by: Brian E Rogers <brian.e.rogers@intel.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
2016-08-10 14:15:57 +03:00
Baolin Wang
72704f876f dwc3: gadget: Implement the suspend entry event handler
It had changed to be suspend event for BIT6 in DEVT register from
version 2.30a and above. Thus this patch introduces one suspend
event handler to handle the suspend event.

Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
2016-06-21 11:16:01 +03:00
Roger Quadros
9522def400 usb: dwc3: core: cleanup IRQ resources
Implementations might use different IRQs for
host, gadget so use named interrupt resources
to allow device tree to specify the interrupts.

Following are the interrupt names

Peripheral Interrupt - peripheral
HOST Interrupt - host

Maintain backward compatibility for a single named
interrupt ("dwc3_usb3") for all interrupts as well as
unnamed interrupt at index 0 for all interrupts.

As platform_get_irq() variants are used, tackle
the -EPROBE_DEFER case as well.

Signed-off-by: Roger Quadros <rogerq@ti.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
2016-06-21 10:53:22 +03:00
Baolin Wang
da1410be21 usb: dwc3: gadget: Add the suspend state checking when stopping gadget
It will be crash to stop gadget when the dwc3 device had been into suspend
state, thus we need to check if the dwc3 device had been into suspend state
when UDC try to stop gadget.

Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
2016-06-21 10:44:37 +03:00
Felipe Balbi
0e146028ee usb: dwc3: gadget: issue ENDTRANSFER conditional on resource_index
Because of recent changes to transfer handling on
DWC3, we will not get XferComplete unless we
completely fill up our TRB ring. This means that we
might get a Reset or Disconnect without getting a
XferComplete first.

In order to correctly release our allocated Transfer
Resource, we must issue ENDTRANSFER command whenever
dep->resource_index is valid.

Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
2016-06-21 10:38:44 +03:00
Felipe Balbi
b6d4e16e83 usb: dwc3: gadget: simplify run_stop() break condition
it's clear now that when is_on=true, we must loop
until DWC3_DSTS_DEVCTRLHLT clears; while when
is_on=false we must loop until DWC3_DSTS_DEVCTRLHLT
gets set.

Instead of adding actual if() statements, we can
rely on XOR operation to evaluate to true only when
the above conditions apply. Then, we can move the
break condition back to the while() statement
together with our timeout check and the resulting
code is very compact and simpler to read.

Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
2016-06-21 10:38:43 +03:00
Felipe Balbi
f2df679b6c usb: dwc3: gadget: avoid while(1) in run_stop()
instead of looping forever and forcing a return if
timeout reaches zero, we can just use timeout and
loop's break condition directly.

Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
2016-06-21 10:38:43 +03:00
Felipe Balbi
d807bdd028 usb: dwc3: gadget: remove udelay() from run_stop()
testing shows that udelay() is unnecessary as
controller reaches Halted state almost
instantenously as can be seen by our timeout
variable never actually decrementing.

Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
2016-06-21 10:38:42 +03:00
Felipe Balbi
21e64bf20d usb: dwc3: gadget: rename 'ignore' argument to 'modify'
'modify' is what the current action is called. Let's
rename it so it matches databook. While at that,
also make sure to add support 'init' action too.

Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
2016-06-21 10:38:41 +03:00
Felipe Balbi
d6dc2e76a8 usb: dwc3: gadget: decrement trbs_left for each sg entry
If we don't, we will overwrite valid TRBs.

Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
2016-06-20 12:32:51 +03:00
Felipe Balbi
ba62c09d5c usb: dwc3: gadget: start Bulk endpoints more frequently
Now we can try to issue Update Transfer every time
gadget driver queues a new request. This will make
sure we keep controller's queue busy for as long as
possible.

Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
2016-06-20 12:32:51 +03:00
Felipe Balbi
13fa2e69b1 usb: dwc3: gadget: disable XFER_NOT_READY
We don't need this IRQ anymore for interrupt or bulk
endpoints.

Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
2016-06-20 12:32:50 +03:00
Felipe Balbi
55a0237f8f usb: dwc3: gadget: use allocated/queued reqs for LST bit
Let's only set LST bit when we run out of space in
our TRB ring. For all other cases, we keep LST bit
unset which will prevent constant allocation and
deallocation of endpoint transfer resources.

Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
2016-06-20 12:32:50 +03:00
Felipe Balbi
69450c4dc1 usb: dwc3: gadget: halt and stop based HWO bit
Instead of relying on empty list of queued requests,
let's rely on the fact that we have a TRB being
processed right now.

Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
2016-06-20 12:32:50 +03:00
Felipe Balbi
68d34c8a74 usb: dwc3: gadget: keep track of allocated and queued reqs
We will be using this information to change how we
figure out when we need LST bit. For now, just
update our counters.

Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
2016-06-20 12:32:49 +03:00
Felipe Balbi
b6b1c6db4c usb: dwc3: gadget: update transfer needs transfer resource
According to SNPS databook, we need to pass transfer
resource on update transfer command, let's do it.

Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
2016-06-20 12:32:49 +03:00
Felipe Balbi
60cfb37ac9 usb: dwc3: remove trailing newline from dwc3_trace
when passing strings to trace, we don't need the
trailing newline character. Trace already appends a
newline character automatically.

Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
2016-06-20 12:32:48 +03:00
John Youn
2da9ad761e usb: dwc3: Use the correct speed macros for DSTS/DCFG
Correct the use of the DWC3_DSTS_XXX_SPEED and DWC3_DCFG_XXX_SPEED
macros. The wrong set of macros were being used in a few places.

This is only a cosmetic change as the values for both sets are
identical.

Signed-off-by: John Youn <johnyoun@synopsys.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
2016-06-20 12:32:45 +03:00
John Youn
3de2685f0c usb: dwc3: gadget: Fix truncated cast issue
From sparse:
warning: cast truncates bits from constant value (100 becomes 0)

The DWC3_TRB_NUM constant is too big for u8. Do the calculation a
slightly different way that should still be optimized out for the case
where DWC3_TRB_NUM == 256.

Signed-off-by: John Youn <johnyoun@synopsys.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
2016-06-20 12:32:45 +03:00
John Youn
361572b5f7 usb: dwc3: gadget: Handle TRB index 0 when full or empty
If the trb->enqueue == trb->dequeue, then it could be full or empty.
This could also happen at TRB index 0, so modify the check to handle
that condition. At index 0, the previous TRB is the one just before the
link TRB.

Signed-off-by: John Youn <johnyoun@synopsys.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
2016-06-20 12:32:45 +03:00
John Youn
7d0a038b13 usb: dwc3: gadget: Account for link TRB in TRBs left
The TRBs left calculation didn't account for the link TRB taking up one
spot.

If the trb_dequeue < trb_enqueue, then the result includes the link
TRB slot so it must be adjusted.

Signed-off-by: John Youn <johnyoun@synopsys.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
2016-06-20 12:32:44 +03:00
John Youn
32db3d9437 usb: dwc3: gadget: Account for max size in TRB space
The current calculation takes dep->trb_dequeue - dep->trb_enqueue to
find the TRB space left.

If you enqueue 1, that results in:
(u8) 0 - (u8) 1 = 0xff = 255 TRBs left.

This is correct if DWC3_TRB_NUM == 256.

If DWC3_TRB_NUM is less than 256 (but still a power of 2) you need to
mod the result by DWC3_TRB_NUM.

For example the same calculation with DWC3_TRB_NUM = 8, results in:
255 % 6 = 7 TRBs left.

Signed-off-by: John Youn <johnyoun@synopsys.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
2016-06-20 12:32:44 +03:00
John Youn
89bc856e5a usb: dwc3: gadget: Don't prepare TRBs if no space
If trbs_left == 0, we don't have any space left in the TRB ring so don't
prepare anything.

Signed-off-by: John Youn <johnyoun@synopsys.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
2016-06-20 12:32:44 +03:00
John Youn
0d25744ad1 usb: dwc3: gadget: Initialize the TRB ring
Clears out all the TRBs in the ring to clean up any stale data that
might be in them from the previous time the endpoint was enabled.

Also removed the existing clear of the LINK trb since the entire ring is
cleard just before.

Signed-off-by: John Youn <johnyoun@synopsys.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
2016-06-20 12:32:43 +03:00