Don't queue both a reset endpoint command and a
set TR deq command at once when handling a halted endpoint.

split this into two steps.
Initially only queue a reset endpoint command, and then if needed queue a
set TR deq command in the reset endpoint handler.

Note: This removes the RESET_EP_QUIRK handling which was added in
commit ac9d8fe7 ("USB: xhci: Add quirk for Fresco Logic xHCI hardware.")

This quirk was added in 2009 for prototype xHCI hardware meant for
evaluation purposes only, and should not reach consumers.
This hardware could not handle two commands queued at once, and had
bad data in the output context after a reset endpoint command.

After this patch two command are no longer queued at once, so that
part is solved  in this rewrite, but the workaround for bad data in the
output context solved by issuing an extra configure endpoint command is
bluntly removed.

Adding this workaround to the new rewrite just adds complexity, and I
think it's time to let this quirk go.
Print a debug message instead.
Signed-off-by: NMathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20210129130044.206855-22-mathias.nyman@linux.intel.comSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Halted endpoints can be discoverd both when handling transfer events and
command completion events. Move code that handles halted endpoints before
both of those event handlers.

Rename the function to xhci_handle_halted_ep() to better describe
what it does. Try to reserve "cleanup" word in function names for last
stage cleanup activities.

No functional changes
Signed-off-by: NMathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20210129130044.206855-21-mathias.nyman@linux.intel.comSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Refactor handler for stop endpoint command completion. Yank out the part
that invalidates cancelled TDs and turn it into a separate function.

Invalidating cancelled TDs should be done while the ring is stopped,
but not exclusively in the stop endpoint command completeion handler.

We will need to invalidate TDs after resetting endpoints as well.
Signed-off-by: NMathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20210129130044.206855-20-mathias.nyman@linux.intel.comSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

In cases where the TD can't be given back in current handler we want
to be able to store it until its time to return the TD.
Signed-off-by: NMathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20210129130044.206855-19-mathias.nyman@linux.intel.comSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

use the existing xhci_td_cleanup() to give back cancelled TDs when a
ring is stopped.

A minor change to make sure we don't try to remove an already removed
td from the list is needed as cancelled TDs are already removed from the
td_list immediatelty when it's cancelled.
Signed-off-by: NMathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20210129130044.206855-18-mathias.nyman@linux.intel.comSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

No funtional changes
Signed-off-by: NMathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20210129130044.206855-17-mathias.nyman@linux.intel.comSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Create a separate helper function to issue reset endpont commands
to clear halted endpoints.

This is useful for cases where a halted endpoint is discovered while
completing another command, and the endpoint halt needs to be cleared
with a endpoint reset first.

No functional changes
Signed-off-by: NMathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20210129130044.206855-16-mathias.nyman@linux.intel.comSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Stop endpoint command fails with "context state error" if the endpoint is
already stopped.

This case was observed when a previous URB cancel had just completed and
rang the doorbell to restart the ring, when a new URB cancel queued a stop
endpoint command.
>From xHC hardware pov the endpoint had not yet started, so the stop
endpoint command failed with context state error.
Right after this the doorbell ring took effect and ring was restarted.

Interrupt handler saw a stop endpoint command completion event with
"context state error" and discovered that the ring was back up in
running state.

flushing the write reduces these cases in stress testing, but does not
completely remove the issue.
Signed-off-by: NMathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20210129130044.206855-15-mathias.nyman@linux.intel.comSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

xhci driver relies on link TRBs existing in the correct places in TRB
ring buffers shared with the host controller.
The controller should not modify these link TRBs, but in theory a faulty
xHC could do it.

Add some basic sanity checks to avoid infinite loops in interrupt handler,
or accessing unallocated memory outside a ring segment due to missing or
misplaced link TRBs.
Signed-off-by: NMathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20210129130044.206855-14-mathias.nyman@linux.intel.comSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Instead of re-reading, masking and endianness correcting the same trb
several times to get the trb type from an event, just do it once and
store it in a local variable.

Also pass the trb_type directly to the vendor specific event handler,
avoiding one more similar read.

In addition to the security benefit this also cleans up the code
and helps readability.
Signed-off-by: NMathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20210129130044.206855-13-mathias.nyman@linux.intel.comSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

When finishing a TD we walk the endpoint dequeue trb pointer
until it matches the last TRB of the TD.

TDs can contain over 100 TRBs, meaning we call a function 100 times,
do a few comparisons and increase a couple values for each of these calls,
all in interrupt context.

This can all be avoided by adding a pointer to the last TRB segment, and
a number of TRBs in the TD. So instead of walking through each TRB just
set the new dequeue segment, pointer, and number of free TRBs directly.

Getting rid of the while loop also reduces the risk of getting stuck in a
infinite loop in the interrupt handler. Loop relied on valid matching
dequeue and last_trb values to break.
Signed-off-by: NMathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20210129130044.206855-12-mathias.nyman@linux.intel.comSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Check that the slot_id that we dug out from command completion event
TRB, is valid before using it to identify the slot associated with the
command that generated the event.
Signed-off-by: NLalithambika Krishna Kumar <lalithambika.krishnakumar@intel.com>
Signed-off-by: NMathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20210129130044.206855-11-mathias.nyman@linux.intel.comSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

xhci driver links together segments in a ring buffer by turning the last
TRB of a segment into a link TRB, pointing to the beginning of
the next segment.

If the first TRB of every segment for some unknown reason is a link TRB
pointing to the next segment, then prepare_ring() loops indefinitely.
This isn't something the xhci driver would do.
xHC hardware has access to these rings, it sholdn't be writing link
TRBs either, but with broken xHC hardware this could in theory be
possible.
Signed-off-by: NMathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20210129130044.206855-10-mathias.nyman@linux.intel.comSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The one case that used this function can use the
xhci_triad_to_transfer_ring() helper instead.

Avoid having several functions doing basically the same thing.
Signed-off-by: NMathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20210129130044.206855-9-mathias.nyman@linux.intel.comSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Two existing ring helpers, xhci_triad_to_transfer_ring() and
xhci_stream_id_to_ring() have partially similar functionality.
Both have some limitation, especieally with boundary checking.

Add a new xhci_virt_ep_to_ring() helper with proper boundary checking
that can replace parts of one helper, and later will completely
replace the other helper.
Signed-off-by: NMathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20210129130044.206855-8-mathias.nyman@linux.intel.comSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Check that the xhci_virt_dev structure that we dug out based
on a slot_id value from a command completion is valid before
dereferencing it.
Signed-off-by: NMathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20210129130044.206855-7-mathias.nyman@linux.intel.comSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

In several event handlers we need to find the right endpoint
structure from slot_id and ep_index in the event.

Add a helper for this, check that slot_id and ep_index are valid.
Signed-off-by: NMathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20210129130044.206855-6-mathias.nyman@linux.intel.comSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

several command completion handlers are passed the event trb
as a paramtere even if it't not used.
Remove it.
Signed-off-by: NMathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20210129130044.206855-5-mathias.nyman@linux.intel.comSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Instead of passing slot id and endpoint index to
cleanup_halted_endpoint() pass the endpoint structure pointer
as it's already known.

Avoids again digging out the endpoint structure based on
slot id and endpoint index, and passing them along the
call chain for this purpose only.

Add slot_id to the virt_dev structure so that it
can easily be found from a virt_dev, or its child, the
virt_ep endpoint structure.
Signed-off-by: NMathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20210129130044.206855-4-mathias.nyman@linux.intel.comSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

isochronous endpoints do not support streams, meaning that
there is only one ring per endpoint.

Avoid double-fetching the transfer event DMA to get the
ring. Also makes passing the event to skip_isoc_td() uncecessary.
Signed-off-by: NMathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20210129130044.206855-3-mathias.nyman@linux.intel.comSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

When handling transfer events the event is passed along the handling
callpath and parsed again in several occasions.

The event contains slot_id and endpoint index, from which the driver
endpoint structure can be found. There wasn't however a way to get the
endpoint index or parent usb device from this endpoint structure.

A lot of extra event parsing, and thus some DMA doublefetch cases,
and excess variables and code can be avoided by adding endpoint index
and parent usb virt device pointer to the endpoint structure.
Signed-off-by: NMathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20210129130044.206855-2-mathias.nyman@linux.intel.comSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

With some USB network adapters, such as DM96xx, the following message
is seen for each maximum size receive packet.

dwc2 ff540000.usb: dwc2_update_urb_state(): trimming xfer length

This happens because the packet size requested by the driver is 1522
bytes, wMaxPacketSize is 64, the dwc2 driver configures the chip to
receive 24*64 = 1536 bytes, and the chip does indeed send more than
1522 bytes of data. Since the event does not indicate an error condition,
the message is just noise. Demote it to debug level.

Fixes: 7359d482 ("staging: HCD files for the DWC2 driver")
Tested-by: NNicolas Saenz Julienne <nsaenzjulienne@suse.de>
Reviewed-by: NDouglas Anderson <dianders@chromium.org>
Signed-off-by: NGuenter Roeck <linux@roeck-us.net>
Signed-off-by: NNicolas Saenz Julienne <nsaenzjulienne@suse.de>
Link: https://lore.kernel.org/r/20210113112052.17063-4-nsaenzjulienne@suse.deSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

In some situations, the following error messages are reported.

dwc2 ff540000.usb: dwc2_hc_chhltd_intr_dma: Channel 1 - ChHltd set, but reason is unknown
dwc2 ff540000.usb: hcint 0x00000002, intsts 0x04000021

This is sometimes followed by:

dwc2 ff540000.usb: dwc2_update_urb_state_abn(): trimming xfer length

and then:

WARNING: CPU: 0 PID: 0 at kernel/v4.19/drivers/usb/dwc2/hcd.c:2913
			dwc2_assign_and_init_hc+0x98c/0x990

The warning suggests that an odd buffer address is to be used for DMA.

After an error is observed, the receive buffer may be full
(urb->actual_length >= urb->length). However, the urb is still left in
the queue unless three errors were observed in a row. When it is queued
again, the dwc2 hcd code translates this into a 1-block transfer.
If urb->actual_length (ie the total expected receive length) is not
DMA-aligned, the buffer pointer programmed into the chip will be
unaligned. This results in the observed warning.

To solve the problem, abort input transactions after an error with
unknown cause if the entire packet was already received. This may be
a bit drastic, but we don't really know why the transfer was aborted
even though the entire packet was received. Aborting the transfer in
this situation is less risky than accepting a potentially corrupted
packet.

With this patch in place, the 'ChHltd set' and 'trimming xfer length'
messages are still observed, but there are no more transfer attempts
with odd buffer addresses.

Fixes: 151d0cbd ("usb: dwc2: make the scheduler handle excessive NAKs better")
Cc: Boris ARZUR <boris@konbu.org>
Cc: Douglas Anderson <dianders@chromium.org>
Tested-by: NNicolas Saenz Julienne <nsaenzjulienne@suse.de>
Reviewed-by: NDouglas Anderson <dianders@chromium.org>
Signed-off-by: NGuenter Roeck <linux@roeck-us.net>
Signed-off-by: NNicolas Saenz Julienne <nsaenzjulienne@suse.de>
Link: https://lore.kernel.org/r/20210113112052.17063-3-nsaenzjulienne@suse.deSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The DWC2 documentation states that transfers with zero data length should
set the number of packets to 1 and the transfer length to 0. This is not
currently the case for inbound transfers: the transfer length is set to
the maximum packet length. This can have adverse effects if the chip
actually does transfer data as it is programmed to do. Follow chip
documentation and keep the transfer length set to 0 in that situation.

Fixes: 56f5b1cf ("staging: Core files for the DWC2 driver")
Tested-by: NNicolas Saenz Julienne <nsaenzjulienne@suse.de>
Reviewed-by: NDouglas Anderson <dianders@chromium.org>
Signed-off-by: NGuenter Roeck <linux@roeck-us.net>
Signed-off-by: NNicolas Saenz Julienne <nsaenzjulienne@suse.de>
Link: https://lore.kernel.org/r/20210113112052.17063-2-nsaenzjulienne@suse.deSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Update Raw Gadget documentation and Kconfig. Make the description more
precise and clear, fix typos and grammar mistakes, and do other cleanups.
Signed-off-by: NAndrey Konovalov <andreyknvl@google.com>
Link: https://lore.kernel.org/r/f4c650c94ae2b910e38819d51109cd5f0b251a2a.1611429174.git.andreyknvl@google.comSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Add copyright to drivers/usb/gadget/legacy/raw_gadget.c.
Signed-off-by: NAndrey Konovalov <andreyknvl@google.com>
Link: https://lore.kernel.org/r/c8937266c4a5da073ac81cd471b18d869c984dfe.1611429174.git.andreyknvl@google.comSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Tasklets have long been deprecated as being too heavy on the system
by running in irq context - and this is not a performance critical
path. If a higher priority process wants to run, it must wait for
the tasklet to finish before doing so.

c67x00_do_work() will now run in process context and have further
concurrency (tasklets being serialized among themselves), but this
is done holding the c67x00->lock, so it should be fine. Furthermore,
this patch fixes the usage of the lock in the callback as otherwise
it would need to be irq-safe.
Signed-off-by: NDavidlohr Bueso <dbueso@suse.de>
Link: https://lore.kernel.org/r/20210113031537.79859-1-dave@stgolabs.netSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Add terminating '\n' to the formats where missed.
Reviewed-by: NGuenter Roeck <linux@roeck-us.net>
Signed-off-by: NJunlin Yang <yangjunlin@yulong.com>
Link: https://lore.kernel.org/r/20210124143947.1688-1-angkery@163.comSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

PTR_ERR(chip->tcpci) has been used as a return value,
it is not necessary to assign it to ret, so remove it.
Reviewed-by: NGuenter Roeck <linux@roeck-us.net>
Reviewed-by: NHeikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: NJunlin Yang <yangjunlin@yulong.com>
Link: https://lore.kernel.org/r/20210124143853.1630-1-angkery@163.comSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

If the port partner is PD2, the PDOs of the local port should follow the
format defined in PD2 Spec. Dynamically modify the pre-defined PD3 PDOs
and transform them into PD2 format before sending them to the PD2 port
partner.
Reviewed-by: NGuenter Roeck <linux@roeckus.net>
Signed-off-by: NKyle Tso <kyletso@google.com>
Link: https://lore.kernel.org/r/20210115163311.391332-1-kyletso@google.comSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This driver includes the legacy GPIO header <linux/gpio.h>,
the new GPIO header <linux/gpio/consumer.h> and
the deprecated OF GPIO header <linux/of_gpio.h> yet
fail to use symbols from any of them, so drop these
includes.

Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Reviewed-by: NGuenter Roeck <linux@roeck-us.net>
Reviewed-by: NHeikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20210120225045.173556-1-linus.walleij@linaro.orgSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Port partner could send PR_SWAP/DR_SWAP/VCONN_SWAP/Request just after it
enters Ready states. This will cause conficts if the port is going to
send DISC_IDENT in the Ready states of TCPM. Set a flag indicating that
the state machine is processing VDM and respond Wait messages until the
VDM state machine stops.
Tested-by: NHans de Goede <hdegoede@redhat.com>
Reviewed-by: NHeikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: NKyle Tso <kyletso@google.com>
Link: https://lore.kernel.org/r/20210114145053.1952756-4-kyletso@google.comSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

PD3.0 Spec 6.8.1 describes how to handle Protocol Error. There are
general rules defined in Table 6-61 which regulate incoming Message
handling. If the incoming Message is unexpected, unsupported, or
unrecognized, Protocol Error occurs. Follow the rules to handle these
situations. Also consider PD2.0 connection (PD2.0 Spec Table 6-36) for
backward compatibilities.

To know the types of AMS in all the recipient's states, identify those
AMS who are initiated by the port partner but not yet recorded in the
current code.

Besides, introduce a new state CHUNK_NOT_SUPP to delay the NOT_SUPPORTED
message after receiving a chunked message.
Tested-by: NHans de Goede <hdegoede@redhat.com>
Reviewed-by: NHeikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: NKyle Tso <kyletso@google.com>
Link: https://lore.kernel.org/r/20210114145053.1952756-3-kyletso@google.comSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This patch provides the implementation of Collision Avoidance introduced
in PD3.0. The start of each Atomic Message Sequence (AMS) initiated by
the port will be denied if the current AMS is not interruptible. The
Source port will set the CC to SinkTxNG if it is going to initiate an
AMS, and SinkTxOk otherwise. Meanwhile, any AMS initiated by a Sink port
will be denied in TCPM if the port partner (Source) sets SinkTxNG except
for HARD_RESET and SOFT_RESET.
Tested-by: NHans de Goede <hdegoede@redhat.com>
Reviewed-by: NHeikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: NKyle Tso <kyletso@google.com>
Link: https://lore.kernel.org/r/20210114145053.1952756-2-kyletso@google.comSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The bdc pci driver is going to be removed due to it not existing in the
wild. This patch turns off compilation of the driver so that stable
kernels can also pick up the change. This helps the out-of-tree
facetimehd webcam driver as the pci id conflicts with bdc.

Cc: Al Cooper <alcooperx@gmail.com>
Cc: <stable@vger.kernel.org>
Acked-by: NFelipe Balbi <balbi@kernel.org>
Signed-off-by: NPatrik Jakobsson <patrik.r.jakobsson@gmail.com>
Link: https://lore.kernel.org/r/20210118203615.13995-1-patrik.r.jakobsson@gmail.comSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

As the comment in usb_disconnect() hints, do not defer the
disconnect processing, and instead just do it directly in
the irq handler. This allows the driver to avoid using a
nowadays deprecated tasklet.
Acked-by: NFelipe Balbi <balbi@kernel.org>
Signed-off-by: NDavidlohr Bueso <dbueso@suse.de>
Link: https://lore.kernel.org/r/20210119001653.127975-1-dave@stgolabs.netSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Update old comments as of 8b4c62ae (usb: gadget: u_serial: process RX
in workqueue instead of tasklet).
Acked-by: NFelipe Balbi <balbi@kernel.org>
Signed-off-by: NDavidlohr Bueso <dbueso@suse.de>
Link: https://lore.kernel.org/r/20210119001321.127750-1-dave@stgolabs.netSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Preventing the driver from being built-in when USB Role
Switch Class is being build as module. That fixes a
potential undefined reference error.

Fixes: 89795852 ("usb: typec: ucsi: Add support for USB role switch")
Reported-by: Nkernel test robot <lkp@intel.com>
Signed-off-by: NHeikki Krogerus <heikki.krogerus@linux.intel.com>
Link: https://lore.kernel.org/r/20210119083405.18325-1-heikki.krogerus@linux.intel.comSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

snd_pcm_stream_lock() is held when the ALSA .trigger() callback is called.
The lock of 'struct uac_rtd_params' is not necessary since all its locking
operation are done under the snd_pcm_stream_lock() too.

Also, usb_request .complete() is called with irqs disabled, so saving and
restoring the irqs is not necessary.
Acked-by: NFelipe Balbi <balbi@kernel.org>
Signed-off-by: NJerome Brunet <jbrunet@baylibre.com>
Link: https://lore.kernel.org/r/20210118084931.322861-1-jbrunet@baylibre.comSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

'struct uac_req' purpose is to link 'struct usb_request' to the
corresponding 'struct uac_rtd_params'. However member req is never
used. Using the context of the usb request, we can keep track of the
corresponding 'struct uac_rtd_params' just as well, without allocating
extra memory.
Acked-by: NFelipe Balbi <balbi@kernel.org>
Signed-off-by: NJerome Brunet <jbrunet@baylibre.com>
Link: https://lore.kernel.org/r/20210118084642.322510-4-jbrunet@baylibre.comSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>