device_create() is race-prone, so use the race-free
device_create_drvdata() instead as device_create() is going away.
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Why?:
There are occasions where userspace would like to access sysfs
attributes for a device but it may not know how sysfs has named the
device or the path. For example what is the sysfs path for
/dev/disk/by-id/ata-ST3160827AS_5MT004CK? With this change a call to
stat(2) returns the major:minor then userspace can see that
/sys/dev/block/8:32 links to /sys/block/sdc.
What are the alternatives?:
1/ Add an ioctl to return the path: Doable, but sysfs is meant to reduce
the need to proliferate ioctl interfaces into the kernel, so this
seems counter productive.
2/ Use udev to create these symlinks: Also doable, but it adds a
udev dependency to utilities that might be running in a limited
environment like an initramfs.
3/ Do a full-tree search of sysfs.
[kay.sievers@vrfy.org: fix duplicate registrations]
[kay.sievers@vrfy.org: cleanup suggestions]
Cc: Neil Brown <neilb@suse.de>
Cc: Tejun Heo <htejun@gmail.com>
Acked-by: Kay Sievers <kay.sievers@vrfy.org>
Reviewed-by: SL Baur <steve@xemacs.org>
Acked-by: Kay Sievers <kay.sievers@vrfy.org>
Acked-by: Mark Lord <lkml@rtr.ca>
Acked-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as1109b) makes USB-Persist more resilient to errors. With
the current code, if a normal resume fails, it's an unrecoverable
error. With the patch, if a normal resume fails (and if the device is
enabled for USB-Persist) then a reset-resume is tried.
This fixes the problem reported in Bugzilla #10977.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Fix pointer/int cast in USB devio code, and thus avoid a compiler warning.
A void* data argument passed to bus_find_device() and thence to match_devt()
is used to carry a 32-bit datum. However, casting directly between a u32 and
a pointer is not permitted - there must be an intermediate cast via (unsigned)
long.
This was introduced by the following patch:
commit 94b1c9fa060ece2c8f080583beb6cc6008e41413
Author: Alan Stern <stern@rowland.harvard.edu>
Date: Tue Jun 24 14:47:12 2008 -0400
usbfs: simplify the lookup-by-minor routines
This patch (as1105) simplifies the lookup-by-minor-number code in
usbfs. Instead of passing the minor number to the callback, which
must then reconstruct the entire dev_t value, the patch passes the
dev_t value directly.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: David Howells <dhowells@redhat.com>
Cc: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as1107) fixes a small bug in the usbfs registration and
unregistration code. It avoids leaving an error value stored in the
device's usb_classdev field and it avoids trying to unregister a NULL
pointer. (It also fixes a rather extreme overuse of whitespace.)
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as1106) fixes a race between opening and unregistering
device files in usbfs. The current code drops its reference to the
device and then reacquires it, ignoring the possibility that the
device structure might have been removed in the meantime. It also
doesn't check whether the device is already in the NOTATTACHED state
when the file is opened.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as1105) simplifies the lookup-by-minor-number code in
usbfs. Instead of passing the minor number to the callback, which
must then reconstruct the entire dev_t value, the patch passes the
dev_t value directly.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
USB device files are accessible in two ways: as files in usbfs and as
character device nodes. The two paths are supposed to behave
identically, but they don't. When the underlying USB device is
unplugged, disconnect signals are sent to processes with open usbfs
files (if they requested these signals) but not to processes with open
device node files.
This patch (as1104) fixes the bug by moving the disconnect-signalling
code into a common subroutine which is called from both paths.
Putting this subroutine in devio.c removes the only out-of-file
reference to struct dev_state, and so the structure's declaration can
be moved from usb.h into devio.c.
Finally, the new subroutine performs one extra action: It kills all
the outstanding async URBs. (I'd kill the outstanding synchronous
URBs too, if there was any way to do it.) In the past this hasn't
mattered much, because devices were unregistered from usbfs only
when they were disconnected. But now the unregistration can also
occur whenever devices are unbound from the usb_generic driver. At
any rate, killing URBs when a device is unregistered from usbfs seems
like a good thing to do.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as1024) takes care of a FIXME issue: Drivers that don't
have the necessary suspend, resume, reset_resume, pre_reset, or
post_reset methods will be unbound and their interface reprobed when
one of the unsupported events occurs.
This is made slightly more difficult by the fact that bind operations
won't work during a system sleep transition. So instead the code has
to defer the operation until the transition ends.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch renames the existing usb_reset_device in hub.c to
usb_reset_and_verify_device and renames the existing
usb_reset_composite_device to usb_reset_device. Also the new
usb_reset_and_verify_device does't need to be EXPORTED .
The idea of the patch is that external interface driver
should warn the other interfaces' driver of the same
device before and after reseting the usb device. One interface
driver shoud call _old_ usb_reset_composite_device instead of
_old_ usb_reset_device since it can't assume the device contains
only one interface. The _old_ usb_reset_composite_device
is safe for single interface device also. we rename the two
functions to make the change easily.
This patch is under guideline from Alan Stern.
Signed-off-by: Ming Lei <tom.leiming@gmail.com>
It is the usb interface driver probe() methods that
can't call usb_set_configuration, not usb device driver.
Signed-off-by: Ming Lei <tom.leiming@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as1103) changes the iteration in the USB scatter-gather to
use a standard SG iterator. Otherwise the iteration will fail if it
encounters a chained SG list.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Acked-by: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
From the current implementation of usb_reset_composite_device
function, the iface parameter is no longer useful. This function
doesn't do something special for the iface usb_interface,compared
with other interfaces in the usb_device. So remove the parameter
and fix the related caller.
Signed-off-by: Ming Lei <tom.leiming@gmail.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch removes CVS keywords that weren't updated for a long time
from comments.
Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as1091) changes the way usbcore handles interface
unbinding. If the interface's driver supports "soft" unbinding (a new
flag in the driver structure) then in-flight URBs are not cancelled
and endpoints are not disabled. Instead the driver is allowed to
continue communicating with the device (although of course it should
stop before its disconnect routine returns).
The purpose of this change is to allow drivers to do a clean shutdown
when they get unbound from a device that is still plugged in. Killing
all the URBs and disabling the endpoints before calling the driver's
disconnect method doesn't give the driver any control over what
happens, and it can leave devices in indeterminate states. For
example, when usb-storage unbinds it doesn't want to stop while in the
middle of transmitting a SCSI command.
The soft_unbind flag is added because in the past, a number of drivers
have experienced problems related to ongoing I/O after their disconnect
routine returned. Hence "soft" unbinding is made available only to
drivers that claim to support it.
The patch also replaces "interface_to_usbdev(intf)" with "udev" in a
couple of places, a minor simplification.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as1083) combines hub_quiesce() and hub_stop() into a
single routine. There's no point keeping them separate since they are
usually called together.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as1071) combines hub_activate() and hub_restart() into a
single routine. There's no point keeping them separate, since they
are always called together.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as1082) makes a small optimization to the way the hub
driver carries out port debouncing immediately after a hub is
activated (i.e., initialized, reset, or resumed). If any port-change
statuses are observed, the code will delay for a minimal debounce
period -- thereby making a good start at debouncing all the ports at
once.
If this wasn't sufficient then khubd will debounce any port that still
requires attention. But in most cases it should suffice; it's rare
for a device to need more than a minimal debounce delay. (In the
cases of hub initialization or reset even that is most likely not
needed, since any devices plugged in at such times have probably been
attached for a while.)
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as1073) adds to khubd a way to recover from power-session
interruption caused by transient connect-change or enable-change
events. After the debouncing period, khubd attempts to do a
USB-Persist-style reset or reset-resume. If it works, the connection
will remain unscathed.
The upshot is that we will be more immune to noise caused by EMI. The
grace period is on the order of 100 ms, so this won't permit recovery
from the "accidentally knocked the USB cable out of its socket" type
of event, but it's a start.
As an added bonus, if a device was suspended when the system goes to
sleep then we no longer need to check for power-session interruptions
when the system wakes up. Khubd will naturally see the status change
while processing the device's parent hub and will do the right thing.
The remote_wakeup() routine is changed; now it expects the caller to
acquire the device lock rather than acquiring the lock itself.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as1081) straightens out the logic of the hub_restart()
routine. Each port of the hub is scanned and the driver makes sure
that ports which are supposed to be disabled really _are_ disabled.
Any ports with a significant change in status are flagged in
hub->change_bits, so that khubd can focus on them without the need to
scan all the ports a second time -- which means the hub->activating
flag is no longer needed.
Also, it is now recognized explicitly that the only reason for
resuming a port which was not suspended is to carry out a reset-resume
operation, which happens only in a non-CONFIG_USB_SUSPEND setting.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This reverts Linus's previous patch that is in mainline to make it
easier for the USB hub.c patches that follow this to apply cleanly. The
functionality will be added back in a followon patch in this series.
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as1080) makes a significant change to the way khubd
handles port connect-change and enable-change events. Both types of
event are now debounced, and the debouncing is carried out _before_ an
existing usb_device is unregistered, instead of afterward.
This means that drivers will have to deal with longer runs of errors
when a device is unplugged, but they are supposed to be prepared for
that in any case.
The advantage is that when an enable-change occurs (caused for example
by electromagnetic interference), the debouncing period will provide
time for the cause of the problem to die away. A simple port reset
(added in a forthcoming patch) will then allow us to recover from the
fault.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as1070) creates a new subroutine to check whether a device
can be resumed. This code is needed even when CONFIG_USB_SUSPEND
isn't set, because devices do suspend themselves when the root hub
(and hence the entire bus) is suspended, and power sessions can get
lost during a system sleep even without individual port suspends.
The patch also fixes a loose end in USB-Persist reset-resume handling.
When a low- or full-speed device is attached to an EHCI's companion
controller, the port handoff during resume will cause the companion
port's connect-status-change feature to be set. If that flag isn't
cleared, the port-reset code will think it indicates that the device
has been unplugged and the reset-resume will fail.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
