Commit 467d5c98 ("usb: musb: Implement session bit based runtime PM for
musb-core") started implementing musb generic runtime PM support by
introducing devctl register session bit based state control.

This caused a regression where if a USB mass storage device is connected
to a USB hub, we can get:

usb 1-1: reset high-speed USB device number 2 using musb-hdrc
usb 1-1: device descriptor read/64, error -71
usb 1-1.1: new high-speed USB device number 4 using musb-hdrc

This is because before the USB storage device is connected, musb is
in OTG_STATE_A_SUSPEND. And we currently only set need_finish_resume
in musb_stage0_irq() and the related code calling finish_resume_work
in musb_resume() and musb_runtime_resume() never gets called.

To fix the issue, we can call schedule_delayed_work() directly in
musb_stage0_irq() to have finish_resume_work run.

And we should no longer never get interrupts when when suspended.
We have changed musb to no longer need pm_runtime_irqsafe().
The need_finish_resume flag was added in commit 9298b4aa ("usb:
musb: fix device hotplug behind hub") and no longer applies as far
as I can tell. So let's just remove the earlier code that no longer
is needed.

Fixes: 467d5c98 ("usb: musb: Implement session bit based runtime PM for musb-core")
Reported-by: NBin Liu <b-liu@ti.com>
Signed-off-by: NTony Lindgren <tony@atomide.com>
Signed-off-by: NBin Liu <b-liu@ti.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

During dma teardown for dequque urb, if musb load is high, musb might
generate bogus rx ep interrupt even when the rx fifo is flushed. In such
case any of the follow log messages could happen.

	musb_host_rx 1853: BOGUS RX2 ready, csr 0000, count 0

	musb_host_rx 1936: RX3 dma busy, csr 2020

As mentioned in the current inline comment, clearing ep interrupt in the
teardown path avoids the bogus interrupt.

Clearing ep interrupt is platform dependent, so this patch adds a
platform callback to allow glue driver to clear the ep interrupt.

This bug seems to be existing since the initial driver for musb support,
but I only validated the fix back to v4.1, so only cc stable for v4.1+.

cc: stable@vger.kernel.org # 4.1+
Signed-off-by: NBin Liu <b-liu@ti.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This adds the function musb_get_mode() to get the DT property "dr_mode"
Signed-off-by: NPetr Kulhavy <petr@barix.com>
Acked-by: NSergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: NAlexandre Bailon <abailon@baylibre.com>
Tested-by: NDavid Lechner <david@lechnology.com>
Reviewed-by: NKevin Hilman <khilman@baylibre.com>
Signed-off-by: NBin Liu <b-liu@ti.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

With a USB hub disconnected, devctl can be 0x19 for about a second
on am335x and will stay forever on at least omap3. And we get no
further interrupts when devctl session bit clears. This keeps
PM runtime active.

Let's fix the issue by polling devctl until the session bit clears
or times out. We can do this by making musb->irq_work into
delayed_work.

And with the polling implemented, we can now also have the quirk
for invalid VBUS it to avoid disconnecting too early while VBUS
is ramping up.

Fixes: 467d5c98 ("usb: musb: Implement session bit based runtime
PM for musb-core")
Fixes: 65b3f50e ("usb: musb: Add PM runtime support for MUSB DSPS
Tested-by: NLadislav Michl <ladis@linux-mips.org>
Tested-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: NTony Lindgren <tony@atomide.com>
Signed-off-by: NBin Liu <b-liu@ti.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Commit 65b3f50e ("usb: musb: Add PM runtime support for MUSB DSPS
glue layer") wrongly added a call for pm_runtime_get_sync to otg_timer
that runs in softirq context. That causes a "BUG: sleeping function called
from invalid context" every time when polling the cable status:

[<c015ebb4>] (__might_sleep) from [<c0413d60>] (__pm_runtime_resume+0x9c/0xa0)
[<c0413d60>] (__pm_runtime_resume) from [<c04d0bc4>] (otg_timer+0x3c/0x254)
[<c04d0bc4>] (otg_timer) from [<c0191180>] (call_timer_fn+0xfc/0x41c)
[<c0191180>] (call_timer_fn) from [<c01915c0>] (expire_timers+0x120/0x210)
[<c01915c0>] (expire_timers) from [<c0191acc>] (run_timer_softirq+0xa4/0xdc)
[<c0191acc>] (run_timer_softirq) from [<c010168c>] (__do_softirq+0x12c/0x594)

I did not notice that as I did not have CONFIG_DEBUG_ATOMIC_SLEEP enabled.
And looks like also musb_gadget_queue() suffers from the same problem.

Let's fix the issue by using a list of delayed work then call it on
resume. Note that we want to do this only when musb core and it's
parent devices are awake, and we need to make sure the DSPS glue
timer is stopped as noted by Johan Hovold <johan@kernel.org>.
Note that we already are re-enabling the timer with mod_timer() in
dsps_musb_enable().

Later on we may be able to remove other delayed work in the musb driver
and just do it from pending_resume_work. But this should be done only
for delayed work that does not have other timing requirements beyond
just being run on resume.

Fixes: 65b3f50e ("usb: musb: Add PM runtime support for MUSB DSPS
glue layer")
Reported-by: NJohan Hovold <johan@kernel.org>
Reviewed-by: NJohan Hovold <johan@kernel.org>
Tested-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: NTony Lindgren <tony@atomide.com>
Signed-off-by: NBin Liu <b-liu@ti.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

We can't use static variable first for checking when musb is
initialized when we have multiple musb instances like on am335x.
Tested-by: NLadislav Michl <ladis@linux-mips.org>
Reviewed-by: NJohan Hovold <johan@hovoldconsulting.com>
Tested-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: NTony Lindgren <tony@atomide.com>
Signed-off-by: NBin Liu <b-liu@ti.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

With the session bit based PM runtime working on musb, we've
implemented few quirks to attempt to detect the current state of
the hardware. One of the quirks is for invalid VBUS as peripheral,
but it is not working in all cases.

If we start musb on dm3730 as a peripheral with no cable connected,
we will get the devctl 91 state once and will never idle as there
are not further interrupts from musb. So we need to ignore the first
devctl 91 state as there will be more interrupts if we're connected.

The invalid VBUS state also can happen always when connected to
certain USB hubs. Looks like musb on dm3730 can claim invalid VBUS
with some hubs while 3717-evm and BeagleBone don't. This causes
session as peripheral to fail for dm3730 with some hubs.

This too is fixed by ignoring only the first invalid VBUS. When
connected, we can just look at the session bit as that will clear
automatically when the session ends.

Fixes: 467d5c98 ("usb: musb: Implement session bit based runtime PM for musb-core")
Signed-off-by: NTony Lindgren <tony@atomide.com>
Signed-off-by: NBin Liu <b-liu@ti.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

We want to keep musb enabled always when the session bit is
set. This simplifies the PM runtime and allows making it more
generic across the various glue layers.

So far the only exception to just following the session bit is
host mode disconnect where the session bit stays set.

In that case, just allow PM and let the PM runtime autoidle
timeout deal with it.
Signed-off-by: NTony Lindgren <tony@atomide.com>
[b-liu@ti.com: changed using dev_dbg() to musb_dbg()]
Signed-off-by: NBin Liu <b-liu@ti.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

At least on n900 we have phy-twl4030-usb only generating cable
interrupts, and then have a separate USB PHY.

In order for musb to know the real cable status, we need to
clear any cached state until musb is ready. Otherwise the cable
status interrupts will get just ignored if the status does
not change from the initial state.

To do this, let's add a return value to musb_mailbox(), and
reset cached linkstat to MUSB_UNKNOWN on error. Sorry to cause
a bit of churn here, I should have added that already last time
patching musb_mailbox().
Signed-off-by: NTony Lindgren <tony@atomide.com>
Signed-off-by: NBin Liu <b-liu@ti.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

We have MUSB setting pm_runtime_irq_safe with the following
commits:

30a70b02 ("usb: musb: fix obex in g_nokia.ko causing kernel panic")
3e43a072 ("usb: musb: core: add pm_runtime_irq_safe()")

Let's fix things to use delayed work so we can remove the
pm_runtime_irq_safe.

Note that we may want to set this up in a generic way in the
gadget framework eventually.
Signed-off-by: NTony Lindgren <tony@atomide.com>
Signed-off-by: NBin Liu <b-liu@ti.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The musb_hdrc_platform_data::config was defined as a non-const pointer.
However some drivers (e.g. the ux500) set up this pointer to point to a
static structure, which is potentially dangerous. Since the musb core
uses the pointer in a read-only manner the const qualifier was added to
protect the content of the config.
Signed-off-by: NPetr Kulhavy <petr@barix.com>
Acked-by: NSergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Signed-off-by: NBin Liu <b-liu@ti.com>
Signed-off-by: NFelipe Balbi <balbi@kernel.org>

We currently can't unload omap2430 MUSB platform glue driver module and
this cause issues for fixing the MUSB code further. The reason we can't
remove omap2430 is because it uses the PHY functions and also exports the
omap_musb_mailbox function that some PHY drivers are using.

Let's fix the issue by exporting a more generic musb_mailbox function
from the MUSB core and allow platform glue layers to register phy_callback
function as needed.

And now we can now also get rid of the include/linux/musb-omap.h.

Cc: Bin Liu <b-liu@ti.com>
Cc: Felipe Balbi <balbi@ti.com>
Cc: Kishon Vijay Abraham I <kishon@ti.com>
Cc: NeilBrown <neil@brown.name>
Reviewed-by: NKishon Vijay Abraham I <kishon@ti.com>
Signed-off-by: NTony Lindgren <tony@atomide.com>
Signed-off-by: NFelipe Balbi <balbi@ti.com>

Fix musb_platform_get_vbus_status return value in case of platform
implementation is not defined, bringing expected behaviour of
musb_platform_get wrapper. Add musb_vbus_show default method to determine
VBUS status in case platform method is not defined.
Signed-off-by: NRoman Alyautdin <ralyautdin@dev.rtsoft.ru>
Signed-off-by: NFelipe Balbi <balbi@ti.com>

The Allwinner (sunxi) implementation of the musb has its busctl registers
indexed by the MUSB_INDEX register rather then in a flat address space.

This commit turns MUSB_BUSCTL_OFFSET from a macro into an io-op which can
be overridden from the platform ops.
Signed-off-by: NHans de Goede <hdegoede@redhat.com>
Signed-off-by: NFelipe Balbi <balbi@ti.com>

For some reason the musb_write_rxfun* and musb_write_rxhub* functions had
a different function prototype and some extra magic needed on the caller side
compared to their tx counterparts, this commit makes them work the same as
their tx counterparts.
Signed-off-by: NHans de Goede <hdegoede@redhat.com>
Signed-off-by: NFelipe Balbi <balbi@ti.com>

The sunxi otg phy has a bug where it wrongly detects a high speed squelch
when reset on the root port gets de-asserted with a lo-speed device.

The workaround for this is to disable squelch detect before de-asserting
reset, and re-enabling it after the reset de-assert is done.
Signed-off-by: NHans de Goede <hdegoede@redhat.com>
Signed-off-by: NFelipe Balbi <balbi@ti.com>

Set up function pointers for DMA so get closer to
being able to build in all the DMA engines.
Signed-off-by: NTony Lindgren <tony@atomide.com>
Signed-off-by: NFelipe Balbi <balbi@ti.com>

that's not needed anymore. Everything that we
call is irq-safe, so we might as well not
have a delayed work for babble recovery.
Tested-by: NBin Liu <b-liu@ti.com>
Signed-off-by: NFelipe Balbi <balbi@ti.com>

recover is a much better name than reset, considering
we don't really reset the IP, just run platform-specific
babble recovery algorithm.

while at that, also fix a typo in comment and add kdoc
for recover memeber of platform_ops.
Tested-by: NBin Liu <b-liu@ti.com>
Signed-off-by: NFelipe Balbi <balbi@ti.com>

This removes the ifdef clutter a bit and saves few lines.

It also makes it easier to detect the remaining places
where we have conditional building of code done based
on if defined for things like DMA.
Signed-off-by: NTony Lindgren <tony@atomide.com>
Signed-off-by: NFelipe Balbi <balbi@ti.com>

This allows the endpoints to work when multiple MUSB glue
layers are built in.

Cc: Fabio Baltieri <fabio.baltieri@linaro.org>
Cc: Lee Jones <lee.jones@linaro.org>
Cc: Lars-Peter Clausen <lars@metafoo.de>
Acked-by: NLinus Walleij <linus.walleij@linaro.org>
Acked-by: NApelete Seketeli <apelete@seketeli.net>
Signed-off-by: NTony Lindgren <tony@atomide.com>
Signed-off-by: NFelipe Balbi <balbi@ti.com>

MUSB currently breaks badly if we try to build in support
for multiple platforms. This also happens if done as loadable
modules, which is not nice for distros.

Let's fix the issue by adding new struct musb_io for the IO
access functions that the platform code can populate. Note
that we don't want to use the current ops as that's really
platform_data and and set as a const.

This should allow eventually adding function pointers also
for the DMA code to struct musb_io, but that's a whole
different set of patches. For now, let's just fix the PIO
access.
Signed-off-by: NTony Lindgren <tony@atomide.com>
Signed-off-by: NFelipe Balbi <balbi@ti.com>

Attaching a keyboard, using it as a wakeup via
|for f in $(find /sys/devices/ocp.3/47400000.usb -name wakeup)
|do
|	echo enabled > $f
|done

going into standby
|  echo standby >  /sys/power/state

and now a wake up by a pressing a key.
What happens is that the system wakes up but the USB device is dead. The
USB stack tries to send a few control URBs but nothing comes back.
Eventually it gaves up and the device remains dead:
|[  632.559678] PM: Wakeup source USB1_PHY
|[  632.581074] PM: noirq resume of devices complete after 21.261 msecs
|[  632.607521] PM: early resume of devices complete after 10.360 msecs
|[  632.616854] net eth2: initializing cpsw version 1.12 (0)
|[  632.704126] net eth2: phy found : id is : 0x4dd074
|[  636.704048] libphy: 4a101000.mdio:00 - Link is Up - 1000/Full
|[  638.444620] usb 1-1: reset low-speed USB device number 2 using musb-hdrc
|[  653.713435] usb 1-1: device descriptor read/64, error -110
|[  669.093435] usb 1-1: device descriptor read/64, error -110
|[  669.473424] usb 1-1: reset low-speed USB device number 2 using musb-hdrc
|[  684.743436] usb 1-1: device descriptor read/64, error -110
|[  690.065097] PM: resume of devices complete after 57450.744 msecs
|[  690.076601] PM: Finishing wakeup.
|[  690.076627] Restarting tasks ...

It seems that since we got woken up via MUSB_INTR_RESUME the
musb_host_finish_resume() callback is executed before the
resume-callbacks of the PHY and glue layer are invoked. If I delay it
until the glue layer resumed then I don't see this problem.

I also move musb_host_resume_root_hub() into that callback since I don't
see any reason in doing anything resume-link if there are still pieces
not restored.
Signed-off-by: NSebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: NFelipe Balbi <balbi@ti.com>

Currently musb_platform_reset() is only used by dsps.
In case of BABBLE interrupt for other platforms the  musb_platform_reset()
is a NOP. In such situations no need to re-initialize the endpoints.
Also in the latest silicon revision of AM335x, we do have a babble recovery
mechanism without resetting the IP block. In preperation to add that support
its better to have a rest_done return for  musb_platform_reset().
Signed-off-by: NGeorge Cherian <george.cherian@ti.com>
Tested-by: NBin Liu <b-liu@ti.com>
Signed-off-by: NFelipe Balbi <balbi@ti.com>

During babble condition both first disconnect of devices are
initiated. Make sure MUSB controller is reset and re-initialized
after all disconnects.

To acheive this schedule a delayed work for babble recovery.

While at that convert udelay to usleep_range.
Refer Documentation/timers/timers-howto.txt
Signed-off-by: NGeorge Cherian <george.cherian@ti.com>
Tested-by: NBin Liu <b-liu@ti.com>
Signed-off-by: NFelipe Balbi <balbi@ti.com>

Add field to store tusb6010 revision value. Read the revision at
the startup and store to the variable.
Signed-off-by: NMatwey V. Kornilov <matwey@sai.msu.ru>
Signed-off-by: NFelipe Balbi <balbi@ti.com>

Handle BABBLE interrupt error conditions from a work struct handler.
This indirection is necessary as we can't be certain that the phy
functions don't sleep.

Platform layer implementation may pass a babble error down to the core
in order to handle it.
Signed-off-by: NDaniel Mack <zonque@gmail.com>
Signed-off-by: NFelipe Balbi <balbi@ti.com>

Babble interrupts require us to reset the DSPS glue layer. In order to
handle all other recovery tasks independently, add a new hook for
platform-specific implementations of the actual reset.
Signed-off-by: NDaniel Mack <zonque@gmail.com>
Signed-off-by: NFelipe Balbi <balbi@ti.com>

Currently, resume and reset is completed when the USB core calls back
the root hub, asking for the port's state. This results in
unpredictable timing of state assertion, which in turn renders some
USB devices unusable after resume.

Fix this by moving the logic to end the reset and suspend state out of
musb_hub_control() into separate functions called from delayed workers.
GetPortStatus only reports the current state now, without taking any
real action.

The rh_timeout variable is kept in order to define a minimum time gap
between reset and resume only.

FWIW, in my case, a Verbatim "STORE N GO" mass storage device won't
resume cleanly without this patch.
Signed-off-by: NDaniel Mack <zonque@gmail.com>
Signed-off-by: NFelipe Balbi <balbi@ti.com>

I have am335x-evm with one port running in OTG mode. Since commit
fe4cb091 ("usb: musb: gadget: remove hcd initialization") the loaded
gadget does non pop up on the host. All I see is
|usb 4-5: new high-speed USB device number 52 using ehci-pci
|usb 4-5: device descriptor read/64, error -110

Since a later commit 2cc65fea ("usb: musb: add musb_host_setup() and
musb_host_cleanup()) the gadget shows up on the host again but only
in OTG mode (because we have the host init code running). It does not
work in device only mode.
If running in OTG mode and the gadget is removed and added back (rmmod
followed by modprobe of a gadget) then the same error is pops up on the
host side.

This patch ensures that the gadget side also executes musb_start() which
puts the chip in "connect accept" mode. With this change the device
works in OTG & device mode and the gadget can be added & removed
multiple times.
A device (if musb is in OTG mode acting as a host) is only recognized if
it is attached during module load (musb_hdrc module). After the device
unplugged and plugged again the host does not recognize it. We get a
buch of errors if musb running in OTG mode, attached to a host and no
gadget is loaded. Bah.
This is one step forward. Host & device only mode should work. I will
look at OTG later. I looked at this before commit fe4cb091 and OTG wasn't
working there perfectly so I am not sure that it is a regression :)

Cc: <stable@vger.kernel.org> # v3.11
Cc: Daniel Mack <zonque@gmail.com>
Cc: Peter Korsgaard <jacmet@sunsite.dk>
Signed-off-by: NSebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: NFelipe Balbi <balbi@ti.com>

Use the generic PHY framework API to get the PHY. The usb_phy_set_resume
and usb_phy_set_suspend is replaced with power_on and
power_off to align with the new PHY framework.

musb->xceiv can't be removed as of now because musb core uses xceiv.state and
xceiv.otg. Once there is a separate state machine to handle otg, these can be
moved out of xceiv and then we can start using the generic PHY framework.
Signed-off-by: NKishon Vijay Abraham I <kishon@ti.com>
Reviewed-by: NSylwester Nawrocki <s.nawrocki@samsung.com>
Acked-by: NFelipe Balbi <balbi@ti.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The musb driver no longer uses procfs, so get rid of the proc_dir_entry
variable in struct musb.
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NFelipe Balbi <balbi@ti.com>

Define MUSB_PORT_MODE_{HOST,GADGET,DUAL_ROLE} and store the
platform-specified value in struct musb.

Note that MUSB_PORT_MODE_HOST has to be set to 1 in order to match
existing device tree bindings which are already documented but in fact
unusued. For information on the bindings, please refer to

  Documentation/devicetree/bindings/usb/omap-usb.txt
  Documentation/devicetree/bindings/usb/am33xx-usb.txt
Signed-off-by: NDaniel Mack <zonque@gmail.com>
Acked-by: NPeter Korsgaard <jacmet@sunsite.dk>
Signed-off-by: NFelipe Balbi <balbi@ti.com>

The musb struct is currently allocated along with the hcd, which makes
it difficult to build a driver that only acts as gadget device.

Fix this by allocating musb directly, and keep the hcd around as
a pointer in the musb struct.

struct hc_driver musb_hc_driver can now also be static to musb_host.c,
and the macro musb_to_hcd() is just a pointer dereferencer for now, and
will be eliminated later.
Signed-off-by: NDaniel Mack <zonque@gmail.com>
Acked-by: NPeter Korsgaard <jacmet@sunsite.dk>
Signed-off-by: NFelipe Balbi <balbi@ti.com>

This function has its only user in musb_virthub.c, so let's move it
there and make it static.
Signed-off-by: NDaniel Mack <zonque@gmail.com>
Acked-by: NPeter Korsgaard <jacmet@sunsite.dk>
Signed-off-by: NFelipe Balbi <balbi@ti.com>

Let the function declarations live in the header files they belong to,
which makes it easier to stub them out later.
Signed-off-by: NDaniel Mack <zonque@gmail.com>
Acked-by: NPeter Korsgaard <jacmet@sunsite.dk>
Signed-off-by: NFelipe Balbi <balbi@ti.com>

This was related to an old bug on early versions
of TUSB6010 which we don't support anymore.

It's known to cause issues on several other
situations with more recent devices so we
better remove this flag now and come up
with a better workaround should one be deemed
necessary.
Signed-off-by: NFelipe Balbi <balbi@ti.com>

This replaced the handcrafted id handling by the PLATFORM_DEVID_AUTO
value which should do the same thing.

This patch probably also fixes ux500 because I did not find the "musbid"
variable to remove. And we close a tiny-unlikely race window becuase the
old code gave the id back before device was destroyed in the remove
case.

[ balbi@ti.com : fixed up two failed hunks when applying patch ]

Cc: B, Ravi <ravibabu@ti.com>
Cc: Santhapuri, Damodar <damodar.santhapuri@ti.com>
Cc: Mian Yousaf Kaukab <mian.yousaf.kaukab@stericsson.com>
Cc: Bob Liu <lliubbo@gmail.com>
Signed-off-by: NSebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: NFelipe Balbi <balbi@ti.com>

This is part of the workaround for AM35x advisory Advisory 1.1.20.
The advisory says that the IPSS bridge can't handle 8 & 16 bit read
access. An 16bit read access to MUSB_INTRTXE results in an 32bit read
access which also reads INTRRX and therefore may lose interrupts.
This patch uses a shadow register of MUSB_INTRTXE so we only perform
write access to it.
Signed-off-by: NSebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: NFelipe Balbi <balbi@ti.com>

This is part of the workaround for AM35x advisory Advisory 1.1.20.
The advisory says that the IPSS bridge can't handle 8 & 16 bit read
access. An 16bit read access to MUSB_INTRRXE results in an 32bit read
access which also reads INTRUSB and therefore may lose interrupts.
This patch uses a shadow register of MUSB_INTRRXE so we only perform
write access to it.
Signed-off-by: NSebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: NFelipe Balbi <balbi@ti.com>