This patch (as1274) simplifies the counting of transaction-error
retries. Now we will count up from 0 to QH_XACTERR_MAX instead of
down from QH_XACTERR_MAX to 0.
The patch also fixes a small bug: qh->xacterr was not getting
initialized for interrupt endpoints.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Tested-by: Matthijs Kooijman <matthijs@stdin.nl>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as1273) fixes two(!) bugs introduced by the new
Clear-TT-Buffer implementation in ehci-hcd.
It is now possible for an idle QH to have some URBs on its
queue -- this will happen if a Clear-TT-Buffer is pending for
the QH's endpoint. Consequently we should not issue a warning
when someone tries to unlink an URB from an idle QH; instead
we should process the request immediately.
The refcounts for QHs could get messed up, because
submit_async() would increment the refcount when calling
qh_link_async() and qh_link_async() would then refuse to link
the QH into the schedule if a Clear-TT-Buffer was pending.
Instead we should increment the refcount only when the QH
actually is added to the schedule. The current code tries to
be clever by leaving the refcount alone if an unlink is
immediately followed by a relink; the patch changes this to an
unconditional decrement and increment (although they occur in
the opposite order).
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
CC: David Brownell <david-b@pacbell.net>
Tested-by: Manuel Lauss <manuel.lauss@gmail.com>
Tested-by: Matthijs Kooijman <matthijs@stdin.nl>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This fixes up the dev_pm_ops conversion and wires up the callbacks needed
for hibernation.
Signed-off-by: Yoshihiro Shimoda <shimoda.yoshihiro@renesas.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Correct the xHCI code to handle stalls on USB endpoints. We need to move
the endpoint ring's dequeue pointer past the stalled transfer, or the HW
will try to restart the transfer the next time the doorbell is rung.
Don't attempt to clear a halt on an endpoint if we haven't seen a stalled
transfer for it. The USB core will attempt to clear a halt on all
endpoints when it selects a new configuration.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Adds support for controllers that use 64-byte contexts. The following context
data structures are affected by this: Device, Input, Input Control, Endpoint,
and Slot. To accommodate the use of either 32 or 64-byte contexts, a Device or
Input context can only be accessed through functions which look-up and return
pointers to their contained contexts.
Signed-off-by: John Youn <johnyoun@synopsys.com>
Acked-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Make sure the xHCI output device context is 64-byte aligned. Previous
code was using the same structure for both the output device context and
the input control context. Since the structure had 32 bytes of flags
before the device context, the output device context wouldn't be 64-byte
aligned. Define a new structure to use for the output device context and
clean up the debugging for these two structures.
The copy of the device context in the input control context does *not*
need to be 64-byte aligned.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Allocates and initializes the scratchpad buffer array (XHCI 4.20). This is an
array of 64-bit DMA addresses to scratch pages that the controller may use
during operation. The number of pages is specified in the "Max Scratchpad
Buffers" field of HCSPARAMS2. The DMA address of this array is written into
slot 0 of the DCBAA.
Signed-off-by: John Youn <johnyoun@synopsys.com>
Acked-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This is a work around for a bug in the SuperSpeed Endpoint Companion Descriptor
parsing code. It fails in some corner cases, which means ep->ss_ep_comp may be
NULL.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Pass back a babble error when this error code is seen in the transfer event TRB.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The xHCI host controller can be programmed to retry a transfer a certain number
of times per endpoint before it passes back an error condition to the host
controller driver. The xHC will return an error code when the error count
transitions from 1 to 0. Programming an error count of 3 means the xHC tries
the transfer 3 times, programming it with a 1 means it tries to transfer once,
and programming it with 0 means the HW tries the transfer infinitely.
We want isochronous transfers to only be tried once, so set the error count to
one.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Add more debugging to the irq handler, slot context initialization, ring
operations, URB cancellation, and MMIO writes.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The Event Handler Busy bit in the event ring dequeue pointer is write 1 to
clear. Fix the interrupt service routine to clear that bit after the
event handler has run.
xhci_set_hc_event_deq() is designed to update the event ring dequeue pointer
without changing any of the four reserved bits in the lower nibble. The event
handler busy (EHB) bit is write one to clear, so the new value must always
contain a zero in that bit in order to preserve the EHB value.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
When there is a short packet on a control transfer, the xHCI host controller
hardware will generate two events. The first event will be for the data stage
TD with a completion code for a short packet. The second event will be for the
status stage with a successful completion code. Before this patch, the xHCI
driver would giveback the short control URB when it received the event for the
data stage TD. Then it would become confused when it saw a status stage event
for the endpoint for an URB it had already finished processing.
Change the xHCI host controller driver to wait for the status stage event when
it receives a short transfer completion code for a data stage TD.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
There are several xHCI data structures that use two 32-bit fields to
represent a 64-bit address. Since some architectures don't support 64-bit
PCI writes, the fields need to be written in two 32-bit writes. The xHCI
specification says that if a platform is incapable of generating 64-bit
writes, software must write the low 32-bits first, then the high 32-bits.
Hardware that supports 64-bit addressing will wait for the high 32-bit
write before reading the revised value, and hardware that only supports
32-bit writes will ignore the high 32-bit write.
Previous xHCI code represented 64-bit addresses with two u32 values. This
lead to buggy code that would write the 32-bits in the wrong order, or
forget to write the upper 32-bits. Change the two u32s to one u64 and
create a function call to write all 64-bit addresses in the proper order.
This new function could be modified in the future if all platforms support
64-bit writes.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The xHCI functions to queue an URB onto the hardware rings must be called
with the xhci spinlock held. Those functions will allocate memory, and
take a gfp_t memory flags argument. We must pass them the GFP_ATOMIC
flag, since we don't want the memory allocation to attempt to sleep while
waiting for more memory to become available.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
When an endpoint on a device under an xHCI host controller stalls, the
host controller driver must let the hardware know that the USB core has
successfully cleared the halt condition. The HCD submits a Reset Endpoint
Command, which will clear the toggle bit for USB 2.0 devices, and set the
sequence number to zero for USB 3.0 devices.
The xHCI urb_enqueue will accept new URBs while the endpoint is halted,
and will queue them to the hardware rings. However, the endpoint doorbell
will not be rung until the Reset Endpoint Command completes.
Don't queue a reset endpoint command for root hubs. khubd clears halt
conditions on the roothub during the initialization process, but the roothub
isn't a real device, so the xHCI host controller doesn't need to know about the
cleared halt.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The 0.95 xHCI specification requires software to set the "TD size" field
in each transaction request block (TRB). This field gives the host
controller an indication of how much data is remaining in the TD
(including the buffer in the current TRB). Set this field in bulk TRBs
and data stage TRBs for control transfers.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Without this change the loops won't start
Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
Cc: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
I noticed that USB initialization didn't setup correctly on my kirkwood
based board (OpenRD base) if I hadn't initialized USB in U-boot first.
The error message looks like this:
ehci_hcd: USB 2.0 'Enhanced' Host Controller (EHCI) Driver
orion-ehci orion-ehci.0: Marvell Orion EHCI
orion-ehci orion-ehci.0: new USB bus registered, assigned bus number 1
orion-ehci orion-ehci.0: can't setup
orion-ehci orion-ehci.0: USB bus 1 deregistered
orion-ehci orion-ehci.0: init orion-ehci.0 fail, -110
orion-ehci: probe of orion-ehci.0 failed with error -110
which is caused by ehci_halt() timing out in the handshake() call. I
noticed that U-boot does a reset before calling handshake(), so this
patch does the same thing for Linux. USB now works for me.
Signed-off-by: Simon Kagstrom <simon.kagstrom@netinsight.net>
Acked-by: Nicolas Pitre <nico@marvell.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
OMAP: OHCI: hc_driver's stop method should call ohci_stop
Without this, the ohci-omap driver will not cleanup the debugfs
nodes when the driver is unloaded. So the next insmod will fail,
if CONFIG_DEBUG_FS and CONFIG_USB_DEBUG are both selected.
Reported-by: vikram pandita <vikram.pandita@ti.com>
Cc: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Anand Gadiyar <gadiyar@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Move r8a66597 hardware register definitions from the host
controller header file to the platform data header file.
With this change in place we can easily share register
definitions between the host controller driver and a future
gadget driver.
Signed-off-by: Magnus Damm <damm@igel.co.jp>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Convert the r8a66597-hcd driver to use the on_chip flag
from platform data to enable on chip behaviour instead
of relying on CONFIG_SUPERH_ON_CHIP_R8A66597 ugliness.
This makes the code cleaner and also allows us to support
both external and internal r8a66597 with the same kernel.
It also makes the Kconfig part more future proof since
we with this patch can add support for new processors
with on-chip r8a66597 without modifying the Kconfig.
Signed-off-by: Magnus Damm <damm@igel.co.jp>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Convert the r8a66597-hcd driver to dev_pm_ops. This makes
the driver a good PM citizen and removes a warning printout.
Signed-off-by: Magnus Damm <damm@igel.co.jp>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
This patch (as1259b) makes ehci-hcd return the total number of bytes
transferred in urb->actual_length for Isochronous transfers.
Until now, the actual_length value was unaccountably left at 0.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Acked-by: David Brownell <dbrownell@users.sourceforge.net>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as1257) revises the way ehci-hcd detects STALLs. The
logic is a little peculiar because there's no hardware status bit
specifically meant to indicate a STALL. You just have to guess that a
STALL was received if the BABBLE bit (which is fatal) isn't set and
the transfer stopped before all its retries were used up.
The existing code doesn't do this properly, because it tests for MMF
(Missed MicroFrame) and DBE (Data Buffer Error) before testing the
retry counter. Thus, if a transaction gets either MMF or DBE the
corresponding flag is set and the transaction is retried. If the
second attempt receives a STALL then -EPIPE is the correct return
value. But the existing code would see the MMF or DBE flag instead
and return -EPROTO, -ENOSR, or -ECOMM.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Acked-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as1256) changes ehci-hcd and all the other drivers in the
EHCI family to make use of the new clear_tt_buffer callbacks. When a
Clear-TT-Buffer request is in progress for a QH, the QH is not allowed
to be linked into the async schedule until the request is finished.
At that time, if there are any URBs queued for the QH, it is linked
into the async schedule.
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 (as1255) updates the interface for calling
usb_hub_clear_tt_buffer(). Even the name of the function is changed!
When an async URB (i.e., Control or Bulk) going through a high-speed
hub to a non-high-speed device is cancelled or fails, the hub's
Transaction Translator buffer may be left busy still trying to
complete the transaction. The buffer has to be cleared; that's what
usb_hub_clear_tt_buffer() does.
It isn't safe to send any more URBs to the same endpoint until the TT
buffer is fully clear. Therefore the HCD needs to be told when the
Clear-TT-Buffer request has finished. This patch adds a callback
method to struct hc_driver for that purpose, and makes the hub driver
invoke the callback at the proper time.
The patch also changes a couple of names; "hub_tt_kevent" and
"tt.kevent" now look rather antiquated.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
We could just make the USB_OHCI_HCD_PPC_OF option implicit
and selected only if at least one of USB_OHCI_HCD_PPC_OF_BE
and USB_OHCI_HCD_PPC_OF_LE are set.
[ dbrownell@users.sourceforge.net: fix patch manglation and dependencies ]
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Tested-by: Subrata Modak <subrata@linux.vnet.ibm.com>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The isp1760_plat_remove function is declared with __devexit, so the
.remove assignment needs to be wrapped with __devexit_p().
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This is an update to the "usb-ehci-update-toggle-state-for-linked-qhs"
patch. Since an HCD's endpoint_reset method can be called in
interrupt context, it mustn't assume that interrupts are enabled or
that it can sleep.
So we revert to the original way of refreshing QHs' toggle bits. Now
the endpoint_reset method merely clears the toggle flag in the device
structure (as was done before) and starts an async QH unlink. When the
QH is linked again, after the unlink finishes and an URB is queued,
the qh_refresh() routine will update the QH's toggle bit.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Tested-by: David <david@unsolicited.net>
CC: David Brownell <david-b@pacbell.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
FHCI_PORT_DISABLED, -LOW and -FULL are mutually exclusive as status.
Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
Cc: Anton Vorontsov <avorontsov@ru.mvista.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* Remove smp_lock.h from files which don't need it (including some headers!)
* Add smp_lock.h to files which do need it
* Make smp_lock.h include conditional in hardirq.h
It's needed only for one kernel_locked() usage which is under CONFIG_PREEMPT
This will make hardirq.h inclusion cheaper for every PREEMPT=n config
(which includes allmodconfig/allyesconfig, BTW)
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The sh7724 processor has two on-chip r8a66597 blocks, so add
it to the list of processors for SUPERH_ON_CHIP_R8A66597.
Signed-off-by: Magnus Damm <damm@igel.co.jp>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
While it looks like xhci was written with both PCI and non-PCI in mind,
apparently only the former has seen any testing. xhci-mem.o can be "fixed"
with a linux/dmapool.h include, but there are still parts of the code that
make use of struct pci_dev directly. So, at least more work is needed before
this can be turned on for non-PCI builds:
CC drivers/usb/host/xhci-mem.o
drivers/usb/host/xhci-mem.c: In function 'xhci_segment_alloc':
drivers/usb/host/xhci-mem.c:45: error: implicit declaration of function 'dma_pool_alloc'
drivers/usb/host/xhci-mem.c:45: warning: assignment makes pointer from integer without a cast
drivers/usb/host/xhci-mem.c: In function 'xhci_segment_free':
drivers/usb/host/xhci-mem.c:67: error: implicit declaration of function 'dma_pool_free'
drivers/usb/host/xhci-mem.c: In function 'xhci_alloc_virt_device':
drivers/usb/host/xhci-mem.c:239: warning: assignment makes pointer from integer without a cast
drivers/usb/host/xhci-mem.c:248: warning: assignment makes pointer from integer without a cast
drivers/usb/host/xhci-mem.c: In function 'xhci_mem_cleanup':
drivers/usb/host/xhci-mem.c:578: error: implicit declaration of function 'dma_pool_destroy'
drivers/usb/host/xhci-mem.c: In function 'xhci_mem_init':
drivers/usb/host/xhci-mem.c:657: error: implicit declaration of function 'dma_pool_create'
drivers/usb/host/xhci-mem.c:658: warning: assignment makes pointer from integer without a cast
drivers/usb/host/xhci-mem.c:663: warning: assignment makes pointer from integer without a cast
make[3]: *** [drivers/usb/host/xhci-mem.o] Error 1
CC drivers/usb/host/xhci-pci.o
drivers/usb/host/xhci-pci.c: In function 'xhci_pci_reinit':
drivers/usb/host/xhci-pci.c:39: error: implicit declaration of function 'pci_set_mwi'
drivers/usb/host/xhci-pci.c: At top level:
drivers/usb/host/xhci-pci.c:151: error: 'usb_hcd_pci_probe' undeclared here (not in a function)
drivers/usb/host/xhci-pci.c:152: error: 'usb_hcd_pci_remove' undeclared here (not in a function)
drivers/usb/host/xhci-pci.c:155: error: 'usb_hcd_pci_shutdown' undeclared here (not in a function)
drivers/usb/host/xhci-pci.c:159: warning: function declaration isn't a prototype
drivers/usb/host/xhci-pci.c:164: warning: function declaration isn't a prototype
make[3]: *** [drivers/usb/host/xhci-pci.o] Error 1
Cc: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Add Makefile and Kconfig entries for the xHCI host controller driver.
List Sarah Sharp as the maintainer for the xHCI driver.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Narrow down time spent holding the xHCI spinlock so that it's only used to
protect the xHCI rings, not as mutual exclusion. Stop allocating memory
while holding the spinlock and calling xhci_alloc_virt_device() and
xhci_endpoint_init().
The USB core should have locking in it to prevent device state to be
manipulated by more than one kernel thread. E.g. you can't free a device
while you're in the middle of setting a new configuration. So removing
the locks from the sections where xhci_alloc_dev() and
xhci_reset_bandwidth() touch xHCI's representation of the device should be
OK.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Mask off the lower 16 bits of the interrupt control register, instead of
masking off the upper 16 bits. The interrupt moderation interval field is
the lower 16 bytes, and is set to 0x4000 (1ms) by default. The previous
code was adding 40 us to the default value, instead of setting it to 40
us. This makes performance really bad.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The packed attribute allows gcc to muck with the alignment of data
structures, which may lead to byte-wise writes that break atomicity of
writes. Packed should only be used when the compile may add undesired
padding to the structure. Each element of the structure will be aligned
by C based on its size and the size of the elements around it. E.g. a u64
would be aligned on an 8 byte boundary, the next u32 would be aligned on a
four byte boundary, etc.
Since most of the xHCI structures contain only u32 bit values, removing
the packed attribute for them should be harmless. (A future patch will
change some of the twin 32-bit address fields to one 64-bit field, but all
those places have an even number of 32-bit fields before them, so the
alignment should be correct.) Add BUILD_BUG_ON statements to check that
the compiler doesn't add padding to the data structures that have a
hardware-defined layout.
While we're modifying the registers, change the name of intr_reg to
xhci_intr_reg to avoid global conflicts.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Greg KH introduced a bug into xhci_trb_virt_to_dma() when he changed the
type of offset to dma_addr_t from unsigned int and dropped the casts to
unsigned int around the virtual address pointer subtraction.
trb and seg->trbs are both valid pointers to virtual addresses, so the
compiler will mod the subtraction by the size of union trb (16 bytes).
segment_offset is an unsigned long, which is guaranteed to be at least as
big as a void *.
Drop the void * casts in the first if statement because trb and seg->trbs
are both pointers of the same type (pointers to union trb).
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
xhci-mem.c includes calls to dma_pool_alloc() and other functions defined
in linux/dmapool.h. Make sure to include that header file.
Reported-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Make sure the error path in xhci_urb_enqueue() releases the spinlock
before it returns. Reported by Oliver in
http://marc.info/?l=linux-usb&m=124091637311832&w=2
Reported-by: Oliver Neukum <oliver@neukum.org>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Differentiate between SuperSpeed endpoint companion descriptor and the
wireless USB endpoint companion descriptor. Make all structure names for
this descriptor have "ss" (SuperSpeed) in them. David Vrabel asked for
this change in http://marc.info/?l=linux-usb&m=124091465109367&w=2
Reported-by: David Vrabel <david.vrabel@csr.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Force the compiler to write the cycle bit of the Link TRB last. This
ensures that the hardware doesn't think it owns the Link TRB before we set
the chain bit. Reported by Oliver in this thread:
http://marc.info/?l=linux-usb&m=124091532410219&w=2
Reported-by: Oliver Neukum <oliver@neukum.org>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Drop spinlock in xhci_irq() error path.
This fixes the issue reported by Oliver Neukum on this thread:
http://marc.info/?l=linux-usb&m=124090924401444&w=2
Remove unnecessary register read reported by Viral Mehta:
http://marc.info/?l=linux-usb&m=124091326007398&w=2
Reported-by: Oliver Neukum <oliver@neukum.org>
Reported-by: Viral Mehta <viral.mehta@einfochips.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
