When hardware is removed on a Stratus, the system may crash like this:
ACPI: PCI interrupt for device 0000:7c:00.1 disabled
Trying to free nonexistent resource <00000000a8000000-00000000afffffff>
Trying to free nonexistent resource <00000000a4800000-00000000a480ffff>
uhci_hcd 0000:7e:1d.0: remove, state 1
usb usb2: USB disconnect, address 1
usb 2-1: USB disconnect, address 2
Unable to handle kernel paging request at 0000000000100100 RIP:
[<ffffffff88021950>] :uhci_hcd:uhci_scan_schedule+0xa2/0x89c
#4 [ffff81011de17e50] uhci_scan_schedule at ffffffff88021918
#5 [ffff81011de17ed0] uhci_irq at ffffffff88023cb8
#6 [ffff81011de17f10] usb_hcd_irq at ffffffff801f1c1f
#7 [ffff81011de17f20] handle_IRQ_event at ffffffff8001123b
#8 [ffff81011de17f50] __do_IRQ at ffffffff800ba749
This occurs because an interrupt scans uhci->skelqh, which is
being freed. We do the right thing: disable the interrupts in the
device, and do not do any processing if the interrupt is shared
with other source, but it's possible that another CPU gets
delayed somewhere (e.g. loops) until we started freeing.
The agreed-upon solution is to wait for interrupts to play out
before proceeding. No other bareers are neceesary.
A backport of this patch was tested on a 2.6.18 based kernel.
Testing of 2.6.32-based kernels is under way, but it takes us
forever (months) to turn this around. So I think it's a good
patch and we should keep it.
Tracked in RH bz#516851
Signed-Off-By: Pete Zaitcev <zaitcev@redhat.com>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Randy Dunlap reported this error when compiling the xHCI driver:
linux-next-20100104/drivers/usb/host/xhci.h:1214:
sorry, unimplemented: inlining failed in call to 'xhci_get_slot_state': function body not available
The xhci_get_slot_state() function belongs in xhci-dbg.c, since it
involves debugging internal xHCI structures. However, it is only used in
xhci-hcd.c. Some toolchains may have issues since the inlined function
body is not in the xhci.h header file. Remove the inline keyword to avoid
this.
Reported-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Acked-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
urb_priv->tds has type struct td **, not struct td *, so the
elements of the array should have pointer type, not structure type.
Convert kzalloc to kcalloc as well.
The semantic patch that makes this change is as follows:
(http://coccinelle.lip6.fr/)
// <smpl>
@disable sizeof_type_expr@
type T;
T **x;
@@
x =
<+...sizeof(
- T
+ *x
)...+>
// </smpl>
Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
OMAP3 has three HS USB ports so it can have three different regulator
for each PHY connected to each port.
Currently these regulators are assumed to be optional and driver doesn't
fail but continue with the initialization if it doesn't get any regulators.
Regulator supply names has to be mapped in board files as 'hsusbN' where
'N' is port number and can be {0, 1 ,2}.
Signed-off-by: Ajay Kumar Gupta <ajay.gupta@ti.com>
Signed-off-by: Felipe Balbi <felipe.balbi@nokia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
It's really the wireless speed, so rename the thing to make
more sense. Based on a recommendation from David Vrabel
Cc: David Vrabel <david.vrabel@csr.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Use kzalloc rather than kcalloc(1,...)
The semantic patch that makes this change is as follows:
(http://coccinelle.lip6.fr/)
// <smpl>
@@
@@
- kcalloc(1,
+ kzalloc(
...)
// </smpl>
Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
xhci_add_endpoint() is used in the reset path. It must
use GFP_NOIO to avoid a possible deadlock.
Signed-off-by: Oliver Neukum <oliver@neukum.org>
Acked-by: Sarah Sharp <sarah.a.sharp@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Use platform_get_resource() to fetch the memory resource and
resource_size() for calculate the length.
Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Cc: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Use resource_size().
Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Cc: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Use resource_size().
Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Cc: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
EHCI FSL controller preserve its state during sleep mode, so nothing
fancy needs to be done.
Though, during 'deep sleep' mode (as found in MPC831x CPUs) the
controller turns off and needs to be reinitialized upon resume.
This patch adds support for hibernation and resuming after deep sleep.
Based on Dave Liu and Jerry Huang's work[1].
[1] http://www.bitshrine.org/gpp/linux-fsl-2.6.24.3-MPC8315ERDB-usb-power-mangement.patch
Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch fixes following warnings:
ehci-fsl.c:43:5: warning: symbol 'usb_hcd_fsl_probe' was not declared. Should it be static?
ehci-fsl.c:150:6: warning: symbol 'usb_hcd_fsl_remove' was not declared. Should it be static?
Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch fix audio record functionality for some Full speed sound blaster devices.
Issue: Sometimes transaction complete indication is coming from HW one frame later.
Solution: If scan_periodic process now frame or previous frame now-1 and sitd transaction
is not finished yet, exit scan_periodic function and check the same transaction in the next frame.
Signed-off-by: Dimitry Epshtein <dima@marvell.com>
Signed-off-by: Saeed Bishara <saeed@marvell.com>
Cc: David Brownell <dbrownell@users.sourceforge.net>
Cc: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Sometimes disable_periodic() stop scan_periodic before than free_cached_itd_list() was called.
In such case USB Host stacked during disconnect operation
Solution: add call of free_cached_itd_list() function in disable_periodic()
Signed-off-by: Dimitry Epshtein <dima@marvell.com>
Signed-off-by: Saeed Bishara <saeed@marvell.com>
Cc: David Brownell <dbrownell@users.sourceforge.net>
Cc: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Add a new host controller driver method, reset_device(), that the USB core
will use to notify the host of a successful device reset. The call may
fail due to out-of-memory errors; attempt the port reset sequence again if
that happens. Update hub_port_init() to allow resetting a configured
device.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
When a USB device is reset, the xHCI hardware must know, in order to match
the device state and disable all endpoints except control endpoint 0.
Issue a Reset Device command after a USB device is successfully reset.
Wait on the command to finish, and then cache or free the disabled
endpoint rings.
There are four different USB device states that the xHCI hardware tracks:
- disabled/enabled - device connection has just been detected,
- default - the device has been reset and has an address of 0,
- addressed - the device has a non-zero address but no configuration has
been set,
- configured - a set configuration succeeded.
The USB core may issue a port reset when a device is in any state, but the
Reset Device command will fail for a 0.96 xHC if the device is not in the
addressed or configured state. Don't consider this failure as an error,
but don't free any endpoint rings if this command fails.
A storage driver may request that the USB device be reset during error
handling, so use GPF_NOIO instead of GPF_KERNEL while allocating memory
for the Reset Device command.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Add the hub emulation code to allow ports on an xHCI root hub to be
disabled. Add the code to clear the port enabled/disabled bit, and clear
the port enabled/disabled change bit. Like EHCI, the port cannot be
enabled by setting the port enabled/disabled bit. Instead, a port is
enabled by the host controller after a reset.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Refactor the code to clear the port change bits in the port status
register. All port status change bits are write one to clear.
Remove a redundant port status read that was supposed to unblock any
posted writes. We read the port after the write to get the updated status
for debugging, so the port read after that is unnecessary.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
All commands that can be issued to the xHCI hardware can come back with
vendor-specific "informational" completion codes. These are to be treated
like a successful completion code. Refactor out the code to test for the
range of these codes and print debugging messages.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The xhci_command structure is the basic structure for issuing commands to
the xHCI hardware. It contains a struct completion (so that the issuing
function can wait on the command), command status, and a input context
that is used to pass information to the hardware. Not all commands need
the input context, so make it optional to allocate. Allow
xhci_free_container_ctx() to be passed a NULL input context, to make
freeing the xhci_command structure simple.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Refactor out the code to cache or free endpoint rings from recently
dropped or disabled endpoints. This code will be used by a new function
to reset a device and disable all endpoints except control endpoint 0.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
If we fail to queue an evaluate context command or a configure endpoint
command to the command ring in xhci_configure_endpoint(), we need to
remove the xhci_command structure from the device's command list before
returning. If the command is left on the command list, it will sit there
indefinitely, blocking commands submitted after this fails.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
On various mxc boards, the intial ULPI reads resulted in a timeout
which prevented the transceiver to be identified and thus the ehci
device to be probed.
Initializing the hardware lines connected to the transceiver (through
pdata->init call) before actually enabling clocks and configuring
registers in the devices fixes this problem.
Signed-off-by: Valentin Longchamp <valentin.longchamp@epfl.ch>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This driver is a Full / Low speed only USB host for the i.MX21.
Signed-off-by: Martin Fuzzey <mfuzzey@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
After kfifo rework FHCI fails to build:
CC drivers/usb/host/fhci-tds.o
drivers/usb/host/fhci-tds.c: In function 'fhci_ep0_free':
drivers/usb/host/fhci-tds.c:108: error: used struct type value where scalar is required
drivers/usb/host/fhci-tds.c:118: error: used struct type value where scalar is required
drivers/usb/host/fhci-tds.c:128: error: used struct type value where scalar is required
This is because kfifos are no longer pointers in the ep struct.
So, instead of checking the pointers, we should now check if kfifo
is initialized.
Reported-by: Josh Boyer <jwboyer@gmail.com>
Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com>
Acked-by: Stefani Seibold <stefani@seibold.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
1. There are two msleep calls inside two spin lock sections, need to unlock
and lock again after msleep.
2. Save a extra status reg setting.
Signed-off-by: Alek Du <alek.du@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The current root hub polling code exhibits a spinlock recursion on the
private controller lock. r8a66597_root_hub_control() is called from
r8a66597_timer() which grabs the lock and disables IRQs. The following
chain emerges:
r8a66597_timer() <-- lock taken
r8a66597_root_hub_control()
r8a66597_check_syssts()
usb_hcd_poll_rh_status() <-- acquires the same lock
/* insert death here */
The entire chain requires IRQs to be disabled, so we just unlock and
relock around the call to usb_hcd_poll_rh_status() while leaving the
IRQ state unchanged.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Acked-by: Yoshihiro Shimoda <shimoda.yoshihiro@renesas.com>
This implements the same D-cache flushing logic for r8a66597-hcd as
Catalin's isp1760 (http://patchwork.kernel.org/patch/76391/) change,
with the same note applying here as well:
When the HDC driver writes the data to the transfer buffers it
pollutes the D-cache (unlike DMA drivers where the device writes
the data). If the corresponding pages get mapped into user space,
there are no additional cache flushing operations performed and
this causes random user space faults on architectures with
separate I and D caches (Harvard) or those with aliasing D-cache.
This fixes up crashes during USB boot on SH7724 and others:
http://marc.info/?l=linux-sh&m=126439837308912&w=2
Reported-by: Goda Yusuke <goda.yusuke@renesas.com>
Tested-by: Goda Yusuke <goda.yusuke@renesas.com>
Cc: stable@kernel.org
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Acked-by: Yoshihiro Shimoda <shimoda.yoshihiro@renesas.com>
This patch improves disable_controller() in the r8a66597-hdc
driver to disable all interrupts and clear status flags. It
also makes sure that disable_controller() is called during
probe(). This fixes the relatively rare case of unexpected
pending interrupts after kexec reboot.
Signed-off-by: Magnus Damm <damm@opensource.se>
Acked-by: Yoshihiro Shimoda <shimoda.yoshihiro@renesas.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
There was some left over #ifdef ARM logic that is outdated but no one
really noticed. So instead of relying on this tricky logic, properly
load and utilize the platform irq_flags resources.
Reported-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Lothar Wassmann <LW@KARO-electronics.de>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Some hosts that treat the return value of sizeof differently from unsigned
long might still hit warnings. So use %zu for sizeof() values. This is a
better version of the previous commit b0a9cf297e.
Signed-off-by: Lothar Wassmann <LW@KARO-electronics.de>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This error message is not actually an error, it's an information
message. It is triggered when a transfer which ended in a NAQ is
retried successfully by the hardware.
Signed-off-by: Colin Tuckley <colin.tuckley@arm.com>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as1330) fixes a bug in khbud's handling of remote
wakeups. When a device sends a remote-wakeup request, the parent hub
(or the host controller driver, for directly attached devices) begins
the resume sequence and notifies khubd when the sequence finishes. At
this point the port's SUSPEND feature is automatically turned off.
However the device needs an additional 10-ms resume-recovery time
(TRSMRCY in the USB spec). Khubd does not wait for this delay if the
SUSPEND feature is off, and as a result some devices fail to behave
properly following a remote wakeup. This patch adds the missing
delay to the remote-wakeup path.
It also extends the resume-signalling delay used by ehci-hcd and
uhci-hcd from 20 ms (the value in the spec) to 25 ms (the value we use
for non-remote-wakeup resumes). The extra time appears to help some
devices.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Cc: stable <stable@kernel.org>
Cc: Rickard Bellini <rickard.bellini@ericsson.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as1321) fixes a problem with EHCI and UHCI root-hub
suspends: If the suspend occurs while a port is trying to resume, the
resume doesn't finish and simply gets lost. When remote wakeup is
enabled, this is undesirable behavior.
The patch checks first to see if any port resumes are in progress, and
if they are then it fails the root-hub suspend with -EBUSY.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as1320) fixes two problems related to interrupt-URB
scheduling in ehci-hcd.
URBs with an interval of 2 or 4 microframes aren't handled.
For the time being, the patch reduces to interval to 1 uframe.
URBs are constrained to have an interval no larger than 1024
frames by usb_submit_urb(). But some EHCI controllers allow
use of a schedule as short as 256 frames; for these
controllers we may have to decrease the interval to the
actual schedule length.
The second problem isn't very significant since few devices expose
interrupt endpoints with an interval larger than 256 frames. But the
first problem is critical; it will prevent the kernel from working
with devices having interrupt intervals of 2 or 4 uframes.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Cc: stable <stable@kernel.org>
Tested-by: Glynn Farrow <farrowg@sg.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
rename kfifo_put... into kfifo_in... to prevent miss use of old non in
kernel-tree drivers
ditto for kfifo_get... -> kfifo_out...
Improve the prototypes of kfifo_in and kfifo_out to make the kerneldoc
annotations more readable.
Add mini "howto porting to the new API" in kfifo.h
Signed-off-by: Stefani Seibold <stefani@seibold.net>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Acked-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Acked-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Move the pointer to the spinlock out of struct kfifo. Most users in
tree do not actually use a spinlock, so the few exceptions now have to
call kfifo_{get,put}_locked, which takes an extra argument to a
spinlock.
Signed-off-by: Stefani Seibold <stefani@seibold.net>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Acked-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Acked-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This is a new generic kernel FIFO implementation.
The current kernel fifo API is not very widely used, because it has to
many constrains. Only 17 files in the current 2.6.31-rc5 used it.
FIFO's are like list's a very basic thing and a kfifo API which handles
the most use case would save a lot of development time and memory
resources.
I think this are the reasons why kfifo is not in use:
- The API is to simple, important functions are missing
- A fifo can be only allocated dynamically
- There is a requirement of a spinlock whether you need it or not
- There is no support for data records inside a fifo
So I decided to extend the kfifo in a more generic way without blowing up
the API to much. The new API has the following benefits:
- Generic usage: For kernel internal use and/or device driver.
- Provide an API for the most use case.
- Slim API: The whole API provides 25 functions.
- Linux style habit.
- DECLARE_KFIFO, DEFINE_KFIFO and INIT_KFIFO Macros
- Direct copy_to_user from the fifo and copy_from_user into the fifo.
- The kfifo itself is an in place member of the using data structure, this save an
indirection access and does not waste the kernel allocator.
- Lockless access: if only one reader and one writer is active on the fifo,
which is the common use case, no additional locking is necessary.
- Remove spinlock - give the user the freedom of choice what kind of locking to use if
one is required.
- Ability to handle records. Three type of records are supported:
- Variable length records between 0-255 bytes, with a record size
field of 1 bytes.
- Variable length records between 0-65535 bytes, with a record size
field of 2 bytes.
- Fixed size records, which no record size field.
- Preserve memory resource.
- Performance!
- Easy to use!
This patch:
Since most users want to have the kfifo as part of another object,
reorganize the code to allow including struct kfifo in another data
structure. This requires changing the kfifo_alloc and kfifo_init
prototypes so that we pass an existing kfifo pointer into them. This
patch changes the implementation and all existing users.
[akpm@linux-foundation.org: fix warning]
Signed-off-by: Stefani Seibold <stefani@seibold.net>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Acked-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Acked-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'omap-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tmlind/linux-omap-2.6:
OMAP3: serial - fix bug introduced in
mfd: twl: fix twl4030 rename for remaining driver, board files
USB ehci: replace mach header with plat
omap3: Allow EHCI to be built on OMAP3
Replace the mach/usb.h with plat/usb.h
Cc: linux-usb-devel@lists.sourceforge.net
Signed-off-by: Thomas Weber <weber@corscience.de>
Acked-by: Felipe Balbi <felipe.balbi@nokia.com>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Tony Lindgren <tony@atomide.com>
The xHCI driver issues a Configure Endpoint command for two reasons:
- a new configuration or alternate interface setting is selected
- a quirky Fresco Logic prototype requires the command after a Reset
Endpoint command.
The xHCI driver only waits on the command in the first case.
When a configure endpoint command completes, the driver needs to know why
the command was generated. When the driver only supported selecting an
initial configuration, the check was simple. Unfortunately that check
doesn't work now that the driver supports alternate interfaces. If an
endpoint must be dropped (because it's not in the new alternate setting)
and no new endpoints are added, the math involving
xhci_last_valid_endpoint() will assign -1 to an unsigned integer and cause
an out-of-bounds array access.
Move the check for the quirky hardware sooner and avoid the bad array
access.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
When a driver wants to switch to a different alternate setting for an
interface, the USB core will (soon) check whether there is enough
bandwidth. Once the new alternate setting is installed in the xHCI
hardware, the USB core will send a USB_REQ_SET_INTERFACE control
message. That can fail in various ways, and the USB core needs to be
able to reinstate the old alternate setting.
With the old code, reinstating the old alt setting could fail if the
there's not enough memory to allocate new endpoint rings. Keep
around a cache of (at most 31) endpoint rings for this case. When we
successfully switch the xHCI hardware to the new alt setting, the old
alt setting's rings will be stored in the cache. Therefore we'll
always have enough rings to satisfy a conversion back to a previous
device setting.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Pete Zaitcev