The xhci_save_registers() function saved the event ring dequeue pointer
in the s3 register structure, but xhci_restore_registers() never
restored it. No other code in the xHCI successful resume path would
ever restore it either. Fix that.
This should be backported to kernels as old as 2.6.37, that contain the
commit 5535b1d5f8 "USB: xHCI: PCI power
management implementation".
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Tested-by: Elric Fu <elricfu1@gmail.com>
Cc: Andiry Xu <andiry.xu@amd.com>
Cc: stable@vger.kernel.org
When xhci_mem_cleanup() is called, we can't be sure if the xHC is
actually halted. We can ask the xHC to halt by writing to the RUN bit
in the command register, but that might timeout due to a HW hang.
If the host controller is still running, we should not write zeroed
values to the event ring dequeue pointers or base tables, the DCBAA
pointers, or the command ring pointers. Eric Fu reports his VIA VL800
host accesses the event ring pointers after a failed register restore on
resume from suspend. The hypothesis is that the host never actually
halted before the register write to change the event ring pointer to
zero.
Remove all writes of zeroed values to pointer registers in
xhci_mem_cleanup(). Instead, make all callers of the function reset the
host controller first, which will reset those registers to zero.
xhci_mem_init() is the only caller that doesn't first halt and reset the
host controller before calling xhci_mem_cleanup().
This should be backported to kernels as old as 2.6.32.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Tested-by: Elric Fu <elricfu1@gmail.com>
Cc: stable@vger.kernel.org
Eric Fu reports a problem with his VIA host controller fetching a zeroed
event ring pointer on resume from suspend. The host should have been
halted, but we can't be sure because that code ignores the return value
from xhci_halt(). Print a warning when the host controller refuses to
halt within XHCI_MAX_HALT_USEC (currently 16 seconds).
(Update: it turns out that the VIA host controller is reporting a halted
state when it fetches the zeroed event ring pointer. However, we still
need this warning for other host controllers.)
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
While we're at that, define IMAN bitfield to aid readability.
The interrupt enable bit should be set once on driver init, and we
shouldn't need to continually re-enable it. Commit c21599a3 introduced
a read of the irq_pending register, and that allows us to preserve the
state of the IE bit. Before that commit, we were blindly writing 0x3 to
the register.
This patch should be backported to kernels as old as 2.6.36, or ones
that contain the commit c21599a361 "USB:
xhci: Reduce reads and writes of interrupter registers".
Signed-off-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: stable@vger.kernel.org
All revisions prior to 2.20a have a known issue which
causes metastability state on Run/Stop bit if we
configure the core to work on any of the USB2-only
speeds.
The suggested workaround is just to never configure the
core to anything other than SuperSpeed.
Signed-off-by: Felipe Balbi <balbi@ti.com>
We have other revisions already released, let's
define revision macros for those so we can do
runtime detection of known erratas.
Signed-off-by: Felipe Balbi <balbi@ti.com>
Fix abuse of interface data which was used to signal device disconnect.
Use the usb_serial disconnect flag and mutex where appropriate.
Note that there's no need to grab the mutex in chase_port as it does not
access the device.
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Kill custom list-based read and write implementations and reimplement
using the generic framework.
Compile-only tested.
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Remove driver version -- it's the kernel version that matters.
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Message in kernel log:
"metro-usb ttyUSB0: Metrologic USB to Serial converter now disconnected from ttyUSB0"
bit more likely than:
"metro-usb ttyUSB0: Metrologic USB to serial converter. converter now disconnected from ttyUSB0"
Signed-off-by: Aleksey Babahin <tamerlan311@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
We should send special control command to tell device start or stop
transmitting a data.
In Bi-Directional mode that cmd`s are not required.
Signed-off-by: Aleksey Babahin <tamerlan311@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This function is never called now. Because we don`t send much data
to the device, only one byte via usb_interrupt_msg(). That doesn't require
callback function. But without declaration of write_int_callback inside
the struct usb_serial_driver, the usb_serial_probe doesn't initialize
endpoint address for the interrupt out pipe(interrupt_out_endpointAddress).
This endpoint is necessary for sending data via usb_interrupt_msg()
function.
Signed-off-by: Aleksey Babahin <tamerlan311@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The right idProduct for Metrologic Bar Code Scanner
in Uni-Directional Serial Emulation mode is 0x0700.
Also rename idProduct for Bi-Directional mode to be a bit more informative.
Signed-off-by: Aleksey Babahin <tamerlan311@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch removes the non-required spinlock acquire/release calls on
'queue_irqlock' from 'uvc_queue_next_buffer' routine.
This routine is called from 'video->encode' function (which translates to either
'uvc_video_encode_bulk' or 'uvc_video_encode_isoc') in 'uvc_video.c'.
As, the 'video->encode' routines are called with 'queue_irqlock' already held,
so acquiring a 'queue_irqlock' again in 'uvc_queue_next_buffer' routine causes
a spin lock recursion.
Signed-off-by: Bhupesh Sharma <bhupesh.sharma@st.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
usb: gadget: eliminate NULL pointer dereference (bugfix)
This patch fixes a bug which causes NULL pointer dereference in
ffs_ep0_ioctl. The bug happens when the FunctionFS is not bound (either
has not been bound yet or has been bound and then unbound) and can be
reproduced with running the following commands:
$ insmod g_ffs.ko
$ mount -t functionfs func /dev/usbgadget
$ ./null
where null.c is:
#include <fcntl.h>
#include <linux/usb/functionfs.h>
int main(void)
{
int fd = open("/dev/usbgadget/ep0", O_RDWR);
ioctl(fd, FUNCTIONFS_CLEAR_HALT);
return 0;
}
Signed-off-by: Andrzej Pietrasiewicz <andrzej.p@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Cc: stable@vger.kernel.org
Signed-off-by: Felipe Balbi <balbi@ti.com>
This patch removes the non-required spinlock acquire/release calls on
'queue->irqlock' from 'uvc_queue_next_buffer' routine.
This routine is called from 'video->encode' function (which translates to
either 'uvc_video_encode_bulk' or 'uvc_video_encode_isoc') in 'uvc_video.c'.
As, the 'video->encode' routines are called with 'queue->irqlock' already held,
so acquiring a 'queue->irqlock' again in 'uvc_queue_next_buffer' routine causes
a spin lock recursion.
Signed-off-by: Bhupesh Sharma <bhupesh.sharma@st.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
It is crucial to assign each req->context value to struct rndis.
The problem happens for multi function gadget (g_multi) when multiple
functions are calling common usb_composite_dev control request.
It might happen that *_setup method from one usb function will
alter some fields of this common request issued by other USB
function.
Signed-off-by: Lukasz Majewski <l.majewski@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
pm_runtime_get_sync returns a signed integer. In case of errors
it returns a negative value. This patch fixes the error check
by making it signed instead of unsigned thus preventing register
access if get_sync_fails. Also passes the error cause to the
debug message.
Cc: stable@vger.kernel.org
Cc: Kishon Vijay Abraham I <kishon@ti.com>
Signed-off-by: Shubhrajyoti D <shubhrajyoti@ti.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
During modprobe of gadget driver, pullup is called after
udc_start. In order to make the exit path symmetric when
removing a gadget driver, call pullup before ->udc_stop.
This is needed to avoid issues with PM where udc_stop
disables the module completely (put IP in reset state,
cut functional and interface clocks, and so on), which
prevents us from accessing the IP's address space,
thus creating the possibility of an abort exception
when we try to access IP's address space after clocks
are off.
Cc: stable@vger.kernel.org
Signed-off-by: Partha Basak <p-basak2@ti.com>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
pm_runtime_enable is being called after omap2430_musb_init. Hence
pm_runtime_get_sync in omap2430_musb_init does not have any effect (does
not enable clocks) resulting in a crash during register access. It is
fixed here.
Cc: stable@vger.kernel.org # v3.0, v3.1, v3.2, v3.3
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
musb can be suspended at the time some other driver wants to do ulpi
transfers using usb_phy_io_* functions, and that can cause data abort,
as it happened with isp1704_charger:
http://article.gmane.org/gmane.linux.kernel/1226122
Add pm_runtime to ulpi functions to rectify this. This also adds io_dev
to usb_phy so that pm_runtime_* functions can be used.
Cc: Felipe Contreras <felipe.contreras@gmail.com>
Signed-off-by: Grazvydas Ignotas <notasas@gmail.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
Control transfers with data expected from device to host will use usb_rcvctrlpipe()
for urb->pipe so for such urbs 'is_in' will be set causing control urb to fall
into the first "if" condition in musb_cleanup_urb().
Fixed by adding logic to check for non control endpoints.
Signed-off-by: Ajay Kumar Gupta <ajay.gupta@ti.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
Array should be freed together with event buffers, since it was
allocated dynamically.
Signed-off-by: Anton Tikhomirov <av.tikhomirov@samsung.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
DMA address register shouldn't be updated manually if transfer size
requires multiple packets.
Signed-off-by: Anton Tikhomirov <av.tikhomirov@samsung.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
Writing to TxFIFO relates only to Slave mode and leads to
TxFIFO corruption in DMA mode.
Signed-off-by: Anton Tikhomirov <av.tikhomirov@samsung.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
According to documentation, TX FIFO_number index starts from 1.
For IN endpoint FIFO 0 we use GNPTXFSIZ register for programming
the size and memory start address.
Signed-off-by: Anton Tikhomirov <av.tikhomirov@samsung.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
- For Control Read transfer, the ACK handshake on an IN transaction
may be corrupted, so the device may not receive the ACK for data
stage, the complete irq will not occur at this situation.
Therefore, we need to move prime status stage from complete irq
routine to the place where the data stage has just primed, or the
host will never get ACK for status stage.
The above issue has been described at USB2.0 spec chapter 8.5.3.3.
- After adding prime status stage just after prime the data stage,
there is a potential problem when the status dTD is added before the data stage
has primed by hardware. The reason is the device's dTD descriptor has NO direction bit,
if data stage (IN) prime hasn't finished, the status stage(OUT)
dTD will be added at data stage dTD's Next dTD Pointer, so when the data stage
transfer has finished, the status dTD will be primed as IN by hardware,
then the host will never receive ACK from the device side for status stage.
- Delete below code at fsl_ep_queue:
/* Update ep0 state */
if ((ep_index(ep) == 0))
udc->ep0_state = DATA_STATE_XMIT;
the udc->ep0_state will be updated again after udc->driver->setup
finishes.
It is tested at i.mx51 bbg board with g_mass_storage, g_ether, g_serial.
Signed-off-by: Peter Chen <peter.chen@freescale.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
When runtime_pm was originally added, it was done in rather confusing
way: omap2430_musb_init() (called from musb_init_controller) would do
runtime_pm_get_sync() and musb_init_controller() itself would do
runtime_pm_put to balance it out. This is not only confusing but also
wrong if non-omap2430 glue layer is used.
This confusion resulted in commit 772aed45b6 "usb: musb: fix
pm_runtime mismatch", that removed runtime_pm_put() from
musb_init_controller as that looked unbalanced, and also happened to
fix unrelated isp1704_charger crash. However this broke runtime PM
functionality (musb is now always powered, even without gadget active).
Avoid these confusing runtime pm dependences by making
musb_init_controller() and omap2430_musb_init() do their own runtime
get/put pairs; also cover error paths. Remove unneeded runtime_pm_put
in omap2430_remove too. isp1704_charger crash that motivated
772aed45b6 will be fixed by following patch.
Cc: Felipe Contreras <felipe.contreras@gmail.com>
Signed-off-by: Grazvydas Ignotas <notasas@gmail.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
This change prevents runtime suspend and resume actual execution, if
omap2430 controller driver is loaded after musb-hdrc, and therefore the
controller isn't initialized properly.
The problem is reproducible with 3.1.y and 3.2 kernels.
Kernel configuration of musb:
% cat .config | egrep 'MUSB|GADGET'
CONFIG_USB_MUSB_HDRC=y
# CONFIG_USB_MUSB_TUSB6010 is not set
CONFIG_USB_MUSB_OMAP2PLUS=m
# CONFIG_USB_MUSB_AM35X is not set
CONFIG_MUSB_PIO_ONLY=y
CONFIG_USB_GADGET=y
# CONFIG_USB_GADGET_DEBUG is not set
# CONFIG_USB_GADGET_DEBUG_FILES is not set
# CONFIG_USB_GADGET_DEBUG_FS is not set
CONFIG_USB_GADGET_VBUS_DRAW=2
CONFIG_USB_GADGET_STORAGE_NUM_BUFFERS=2
CONFIG_USB_GADGET_MUSB_HDRC=m
CONFIG_USB_GADGET_DUALSPEED=y
CONFIG_USB_GADGETFS=m
# CONFIG_USB_MIDI_GADGET is not set
Fixes the following oops on module unloading:
Unable to handle kernel NULL pointer dereference at virtual address 00000220
----8<----
[<bf162088>] (omap2430_runtime_resume+0x24/0x54 [omap2430]) from [<c0302e34>] (pm_generic_runtime_resume+0x3c/0x50)
[<c0302e34>] (pm_generic_runtime_resume+0x3c/0x50) from [<c0031a24>] (_od_runtime_resume+0x28/0x2c)
[<c0031a24>] (_od_runtime_resume+0x28/0x2c) from [<c0306cb0>] (__rpm_callback+0x60/0xa0)
[<c0306cb0>] (__rpm_callback+0x60/0xa0) from [<c0307f2c>] (rpm_resume+0x3fc/0x6e4)
[<c0307f2c>] (rpm_resume+0x3fc/0x6e4) from [<c030851c>] (__pm_runtime_resume+0x5c/0x90)
[<c030851c>] (__pm_runtime_resume+0x5c/0x90) from [<c02fd0dc>] (__device_release_driver+0x2c/0xd0)
[<c02fd0dc>] (__device_release_driver+0x2c/0xd0) from [<c02fda18>] (driver_detach+0xe8/0xf4)
[<c02fda18>] (driver_detach+0xe8/0xf4) from [<c02fcf88>] (bus_remove_driver+0xa0/0x104)
[<c02fcf88>] (bus_remove_driver+0xa0/0x104) from [<c02fde54>] (driver_unregister+0x60/0x80)
[<c02fde54>] (driver_unregister+0x60/0x80) from [<c02ff2d4>] (platform_driver_unregister+0x1c/0x20)
[<c02ff2d4>] (platform_driver_unregister+0x1c/0x20) from [<bf162928>] (omap2430_exit+0x14/0x1c [omap2430])
[<bf162928>] (omap2430_exit+0x14/0x1c [omap2430]) from [<c007d8bc>] (sys_delete_module+0x1f4/0x264)
[<c007d8bc>] (sys_delete_module+0x1f4/0x264) from [<c000f000>] (ret_fast_syscall+0x0/0x30)
Signed-off-by: Vladimir Zapolskiy <vladimir.zapolskiy@nokia.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: stable@vger.kernel.org # 3.1
Signed-off-by: Felipe Balbi <balbi@ti.com>
Without this default case returning an error,
thus replying with a stall, we would fail
USB30CV TD 9.11 Bad Feature test case.
Cc: stable@vger.kernel.org
Signed-off-by: Gerard Cauvy <g-cauvy1@ti.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
due to a HW limitation we have a bounce buffer for ep0
out transfers which are not aligned with MaxPacketSize.
On such case we were not increment r->actual as we should.
This patch fixes that mistake.
Cc: stable@vger.kernel.org
Signed-off-by: Felipe Balbi <balbi@ti.com>
To allow ep0 out transfers of upto bounce buffer size
instead of maxpacketsize, use the transfer size as multiple
of ep0 maxpacket size.
Cc: stable@vger.kernel.org
Signed-off-by: Moiz Sonasath <m-sonasath@ti.com>
Signed-off-by: Partha Basak <p-basak2@ti.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
When we want to do device-initiated disconnect,
let's make sure we stop the UDC in order to
e.g. allow lower power states to be achieved by
turning off unnecessary clocks and/or stoping
PHYs.
When reconnecting, call ->udc_start() again to
make sure UDC is reinitialized.
Cc: stable@vger.kernel.org
Signed-off-by: Felipe Balbi <balbi@ti.com>
This patch (as1538) causes uhci_hub_status_data() to return a nonzero
value when any port is undergoing a resume transition while the root
hub is suspended. This will allow usbcore to handle races between
root-hub suspend and port wakeup.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch (as1537) adds a bit-array to ehci-hcd for keeping track of
which ports are undergoing a resume transition. If any of the bits
are set when ehci_hub_status_data() is called, the routine will return
a nonzero value even if no ports have any status changes pending.
This will allow usbcore to handle races between root-hub suspend and
port wakeup.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
CC: Sarah Sharp <sarah.a.sharp@linux.intel.com>
CC: Chen Peter-B29397 <B29397@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch (as1533) fixes a race between root-hub suspend and remote
wakeup. If a wakeup event occurs while a root hub is suspending, it
might not cause the suspend to fail. Although the host controller
drivers check for pending wakeup events at the start of their
bus_suspend routines, they generally do not check for wakeup events
while the routines are running.
In addition, if a wakeup event occurs any time after khubd is frozen
and before the root hub is fully suspended, it might not cause a
system sleep transition to fail. For example, the host controller
drivers do not fail root-hub suspends when a connect-change event is
pending.
To fix both these issues, this patch causes hcd_bus_suspend() to query
the controller driver's hub_status_data method after a root hub is
suspended, if the root hub is enabled for wakeup. Any pending status
changes will count as wakeup events, causing the root hub to be
resumed and the overall suspend to fail with -EBUSY.
A significant point is that not all events are reflected immediately
in the status bits. Both EHCI and UHCI controllers notify the CPU
when remote wakeup begins on a port, but the port's suspend-change
status bit doesn't get set until after the port has completed the
transition out of the suspend state, some 25 milliseconds later.
Consequently, the patch will interpret any nonzero return value from
hub_status_data as indicating a pending event, even if none of the
status bits are set in the data buffer. Follow-up patches make the
necessary changes to ehci-hcd and uhci-hcd.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
CC: Sarah Sharp <sarah.a.sharp@linux.intel.com>
CC: Chen Peter-B29397 <B29397@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
There are two issues here, one is that the device is generating
spurious very fast modem status line changes somewhere:
CTS becomes high then low 18µs later:
[121226.924373] ftdi_process_packet: prev rng=0 dsr=10 dcd=0 cts=6
[121226.924378] ftdi_process_packet: status=10 prev=00 diff=10
[121226.924382] ftdi_process_packet: now rng=0 dsr=10 dcd=0 cts=7
(wake_up_interruptible is called)
[121226.924391] ftdi_process_packet: prev rng=0 dsr=10 dcd=0 cts=7
[121226.924394] ftdi_process_packet: status=00 prev=10 diff=10
[121226.924397] ftdi_process_packet: now rng=0 dsr=10 dcd=0 cts=8
(wake_up_interruptible is called)
This wakes up the task in TIOCMIWAIT:
[121226.924405] ftdi_ioctl: 19451 rng=0->0 dsr=10->10 dcd=0->0 cts=6->8
(wait from 20:51:46 returns and observes both changes)
Which then calls TIOCMIWAIT again:
20:51:46.400239 ioctl(3, TIOCMIWAIT, 0x20) = 0
22:11:09.441818 ioctl(3, TIOCMGET, [TIOCM_DTR|TIOCM_RTS]) = 0
22:11:09.442812 ioctl(3, TIOCMIWAIT, 0x20) = -1 EIO (Input/output error)
(the second wake_up_interruptible takes effect and an I/O error occurs)
The other issue is that TIOCMIWAIT will wait forever (unless the task is
interrupted) if the device is removed.
This change removes the -EIO return that occurs if the counts don't
appear to have changed. Multiple counts may have been processed as
one or the waiting task may have started waiting after recording the
current count.
It adds a bool to indicate that the device has been removed so that
TIOCMIWAIT doesn't wait forever, and wakes up any tasks so that they can
return -EIO.
Signed-off-by: Simon Arlott <simon@fire.lp0.eu>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Handling of TIOCMIWAIT was changed by commit 1d749f9afa
USB: ftdi_sio.c: Use ftdi async_icount structure for TIOCMIWAIT, as in other drivers
FTDI_STATUS_B0_MASK does not indicate the changed modem status lines,
it indicates the value of the current modem status lines. An xor is
still required to determine which lines have changed.
The count was only being incremented if the line was high. The only
reason TIOCMIWAIT still worked was because the status packet is
repeated every 1ms, so the count was always changing. The wakeup
itself still ran based on the status lines changing.
This change fixes handling of updates to the modem status lines and
allows multiple processes to use TIOCMIWAIT concurrently.
Tested with two processes waiting on different status lines being
toggled independently.
Signed-off-by: Simon Arlott <simon@fire.lp0.eu>
Cc: Uwe Bonnes <bon@elektron.ikp.physik.tu-darmstadt.de>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch (as1532) fixes a mistake in the USB suspend code. When the
system is going to sleep, we should ignore errors in powering down USB
devices, because they don't really matter. The devices will go to low
power anyway when the entire USB bus gets suspended (except for
SuperSpeed devices; maybe they will need special treatment later).
However we should not ignore errors in suspending root hubs,
especially if the error indicates that the suspend raced with a wakeup
request. Doing so might leave the bus powered on while the system was
supposed to be asleep, or it might cause the suspend of the root hub's
parent controller device to fail, or it might cause a wakeup request
to be ignored.
The patch fixes the problem by ignoring errors only when the device in
question is not a root hub.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Reported-by: Chen Peter <B29397@freescale.com>
CC: <stable@vger.kernel.org>
Tested-by: Chen Peter <peter.chen@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch (as1536) fixes a bug in the USB serial core. Unloading and
reloading a serial driver while a serial device is plugged in causes
errors because of the code in usb_serial_disconnect() that tries to
make sure the port_remove method is called. With the new order of
driver registration introduced in the 3.4 kernel, this is definitely
not the right thing to do (if indeed it ever was).
The patch removes that whole section code, along with the mechanism
for keeping track of each port's registration state, which is no
longer needed. The driver core can handle all that stuff for us.
Note: This has been tested only with one or two USB serial drivers.
In theory, other drivers might still run into trouble. But if they
do, it will be the fault of the drivers, not of this patch -- that is,
the drivers will need to be fixed.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Reported-and-tested-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
