Maintain a per-CPU global "struct pt_regs *" variable which can be used instead
of passing regs around manually through all ~1800 interrupt handlers in the
Linux kernel.
The regs pointer is used in few places, but it potentially costs both stack
space and code to pass it around. On the FRV arch, removing the regs parameter
from all the genirq function results in a 20% speed up of the IRQ exit path
(ie: from leaving timer_interrupt() to leaving do_IRQ()).
Where appropriate, an arch may override the generic storage facility and do
something different with the variable. On FRV, for instance, the address is
maintained in GR28 at all times inside the kernel as part of general exception
handling.
Having looked over the code, it appears that the parameter may be handed down
through up to twenty or so layers of functions. Consider a USB character
device attached to a USB hub, attached to a USB controller that posts its
interrupts through a cascaded auxiliary interrupt controller. A character
device driver may want to pass regs to the sysrq handler through the input
layer which adds another few layers of parameter passing.
I've build this code with allyesconfig for x86_64 and i386. I've runtested the
main part of the code on FRV and i386, though I can't test most of the drivers.
I've also done partial conversion for powerpc and MIPS - these at least compile
with minimal configurations.
This will affect all archs. Mostly the changes should be relatively easy.
Take do_IRQ(), store the regs pointer at the beginning, saving the old one:
struct pt_regs *old_regs = set_irq_regs(regs);
And put the old one back at the end:
set_irq_regs(old_regs);
Don't pass regs through to generic_handle_irq() or __do_IRQ().
In timer_interrupt(), this sort of change will be necessary:
- update_process_times(user_mode(regs));
- profile_tick(CPU_PROFILING, regs);
+ update_process_times(user_mode(get_irq_regs()));
+ profile_tick(CPU_PROFILING);
I'd like to move update_process_times()'s use of get_irq_regs() into itself,
except that i386, alone of the archs, uses something other than user_mode().
Some notes on the interrupt handling in the drivers:
(*) input_dev() is now gone entirely. The regs pointer is no longer stored in
the input_dev struct.
(*) finish_unlinks() in drivers/usb/host/ohci-q.c needs checking. It does
something different depending on whether it's been supplied with a regs
pointer or not.
(*) Various IRQ handler function pointers have been moved to type
irq_handler_t.
Signed-Off-By: David Howells <dhowells@redhat.com>
(cherry picked from 1b16e7ac850969f38b375e511e3fa2f474a33867 commit)
This patch (as791b) fixes things up to avoid compiler warnings or
errors when CONFIG_USB_SUSPEND or CONFIG_PM isn't set.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as739) adds the basic infrastructure for USB autosuspend
and autoresume. The main features are:
PM usage counters added to struct usb_device and struct
usb_interface, indicating whether it's okay to autosuspend
them or they are currently in use.
Flag added to usb_device indicating whether the current
suspend/resume operation originated from outside or as an
autosuspend/autoresume.
Flag added to usb_driver indicating whether the driver
supports autosuspend. If not, no device bound to the driver
will be autosuspended.
Mutex added to usb_device for protecting PM operations.
Unlike the device semaphore, the locking rule for the pm_mutex
is that you must acquire the locks going _up_ the device tree.
New routines handling autosuspend/autoresume requests for
interfaces and devices.
Suspend and resume requests are propagated up the device tree
(but not outside the USB subsystem).
work_struct added to usb_device, for carrying out delayed
autosuspend requests.
Autoresume added (and autosuspend prevented) during probe and
disconnect.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as778) adds a field to struct usb_device to store the
device's level in the USB tree. In itself this number isn't really
important. But the overhead is very low, and in a later patch it will
be used for preventing bogus warnings from the lockdep checker.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
As part of the ongoing program to flatten out the HCD bus-glue layer,
this patch (as771b) eliminates the hcpriv, release, and kref fields
from struct usb_bus. hcpriv and release were not being used for
anything worthwhile, and kref has been moved into the enclosing
usb_hcd structure.
Along with those changes, the patch gets rid of usb_bus_get and
usb_bus_put, replacing them with usb_get_hcd and usb_put_hcd.
The one interesting aspect is that the dev_set_drvdata call was
removed from usb_put_hcd, where it clearly doesn't belong. This means
the driver private data won't get reset to NULL. It shouldn't cause
any problems, since the private data is undefined when no driver is
bound.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as770b) introduces a new field to usb_bus: a flag
indicating whether or not the host controller uses DMA. This serves
to encapsulate the computation. It also means we will have only one
spot to update if the DMA API changes.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
All of the currently-supported USB host controller drivers use the HCD
bus-glue framework. As part of the program for flattening out the glue
layer, this patch (as769) removes the usb_operations structure. All
function calls now go directly to the HCD routines (slightly renamed
to remain within the "usb_" namespace).
The patch also removes usb_alloc_bus(), because it's not useful in the
HCD framework and it wasn't referenced anywhere.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
It's generally a bad idea for USB interface drivers to try to change a
device's configuration, and usbcore doesn't provide any way for them
to do it. However in a few exceptional circumstances it can make
sense. This patch (as767) adds a roundabout mechanism to help drivers
that may need it.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch marks some USB core's functions parameters as const. This
improves the design (we're saying to the caller that its parameter is
not going to be modified) and may help in compiler's optimisation work.
Signed-off-by: Luiz Fernando N. Capitulino <lcapitulino@mandriva.com.br>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
These functions makes USB driver's code simpler when dealing with endpoints
by avoiding them from accessing the endpoint's descriptor structure directly
when they only need to know the endpoint's transfer type and/or
direction.
Please, read each functions' documentation in order to know how to use
them.
Signed-off-by: Luiz Fernando N. Capitulino <lcapitulino@mandriva.com.br>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
include/linux/usb.h causes a lot of -Wshadow warnings - fix them.
include/linux/usb.h:901: warning: declaration of 'complete' shadows a global declaration
include/linux/completion.h:52: warning: shadowed declaration is here
include/linux/usb.h:932: warning: declaration of 'complete' shadows a global declaration
include/linux/completion.h:52: warning: shadowed declaration is here
include/linux/usb.h:967: warning: declaration of 'complete' shadows a global declaration
include/linux/completion.h:52: warning: shadowed declaration is here
Signed-off-by: Jesper Juhl <jesper.juhl@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Currently we rely on intf->dev.power.power_state.event for tracking
whether intf is suspended. This is not a reliable technique because
that value is owned by the PM core, not by usbcore. This patch (as718b)
adds a new flag so that we can accurately tell which interfaces are
suspended and which aren't.
At first one might think these flags aren't needed, since interfaces
will be suspended along with their devices. It turns out there are a
couple of intermediate situations where that's not quite true, such as
while processing a remote-wakeup request.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as732) adds a usb_device_driver structure, for representing
drivers that manage an entire USB device as opposed to just an
interface. Support routines like usb_register_device_driver,
usb_deregister_device_driver, usb_probe_device, and usb_unbind_device
are also added.
Unlike an earlier version of this patch, the new code is type-safe. To
accomplish this, the existing struct driver embedded in struct
usb_driver had to be wrapped in an intermediate wrapper. This enables
the core to tell at runtime whether a particular struct driver belongs
to a device driver or to an interface driver.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This reverts c182274ffe commit because it
required a newer version of udev to work properly than what is currently
documented in Documentation/Changes.
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This reverts bd00949647 commit because it
required a newer version of udev to work properly than what is currently
documented in Documentation/Changes.
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Warning(/var/linsrc/linux-2617-g4//include/linux/usb.h:66): No description found for parameter 'ep_dev'
Signed-off-by: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This moves the usb class devices that control the usbfs nodes to show up
in the proper place in the larger device tree.
No userspace changes is needed, this is compatible due to the symlinks
generated by the driver core.
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This will allow for us to give endpoints a major/minor to create a
"usbfs2-like" way to access endpoints directly from userspace in an
easier manner than the current usbfs provides us.
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as699) adds usb_reset_composite_device(), a routine for
sending a USB port reset to a device with multiple interfaces owned by
different drivers. Drivers are notified about impending and completed
resets through two new methods in the usb_driver structure.
The patch modifieds the usbfs ioctl code to make it use the new routine
instead of usb_reset_device(). Follow-up patches will modify the hub,
usb-storage, and usbhid drivers so they can utilize this new API.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Mark the f_ops members of inodes as const, as well as fix the
ripple-through this causes by places that copy this f_ops and then "do
stuff" with it.
Signed-off-by: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
After the removal of usb-midi.c, there's no longer any external user of
usb_get_string().
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Leave the overloaded "hotplug" word to susbsystems which are handling
real devices. The driver core does not "plug" anything, it just exports
the state to userspace and generates events.
Signed-off-by: Kay Sievers <kay.sievers@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as610) adds a field to struct usb_device to store the device's
port number. This allows us to remove several loops in the hub driver
(searching for a particular device among all the entries in the parent's
array of children).
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as609) changes the way we keep track of power budgeting for
USB hubs and devices, and it updates the choose_configuration routine to
take this information into account. (This is something we should have
been doing all along.) A new field in struct usb_device holds the amount
of bus current available from the upstream port, and the usb_hub structure
keeps track of the current available for each downstream port.
Two new rules for configuration selection are added:
Don't select a self-powered configuration when only bus power
is available.
Don't select a configuration requiring more bus power than is
available.
However the first rule is #if-ed out, because I found that the internal
hub in my HP USB keyboard claims that its only configuration is
self-powered. The rule would prevent the configuration from being chosen,
leaving the hub & keyboard unconfigured. Since similar descriptor errors
may turn out to be fairly common, it seemed wise not to include a rule
that would break automatic configuration unnecessarily for such devices.
The second rule may also trigger unnecessarily, although this should be
less common. More likely it will annoy people by sometimes failing to
accept configurations that should never have been chosen in the first
place.
The patch also changes usbcore's reaction when no configuration is
suitable. Instead of raising an error and rejecting the device, now
the core will simply leave the device unconfigured. People can always
work around such problems by installing configurations manually through
sysfs.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as605) removes the private udev->serialize semaphore,
relying instead on the locking provided by the embedded struct device's
semaphore. The changes are confined to the core, except that the
usb_trylock_device routine now uses the return convention of
down_trylock rather than down_read_trylock (they return opposite values
for no good reason).
A couple of other associated changes are included as well:
Now that we aren't concerned about HCDs that avoid using the
hcd glue layer, usb_disconnect no longer needs to acquire the
usb_bus_lock -- that can be done by usb_remove_hcd where it
belongs.
Devices aren't locked over the same scope of code in
usb_new_device and hub_port_connect_change as they used to be.
This shouldn't cause any trouble.
Along with the preceding driver core patch, this needs a lot of testing.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This fixes the driver that forgot to set the module owner up. Now we
can remove the unneeded pointer from the usb driver structure. The idea
for how to do this was from Al Viro, who did this for the PCI drivers.
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This lets drivers, like the usb-serial ones, disable the ability to add
ids from sysfs.
The usb-serial drivers are "odd" in that they are really usb-serial bus
drivers, not usb bus drivers, so the dynamic id logic will have to go
into the usb-serial bus core for those drivers to get that ability.
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Echo the usb vendor and product id to the "new_id" file in the driver's
sysfs directory, and then that driver will be able to bind to a device
with those ids if it is present.
Example:
echo 0557 2008 > /sys/bus/usb/drivers/foo_driver/new_id
adds the hex values 0557 and 2008 to the device id table for the foo_driver.
Note, usb-serial drivers do not currently work with this capability yet.
usb-storage also might have some oddities.
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Many structures contain both an internal part and one which is part of the API
to other modules. With this patch it is possible to only include these public
members in the kernel documentation.
Signed-off-by: Martin Waitz <tali@admingilde.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch (as592) makes a few small improvements to the way device
strings are handled, and it fixes some bugs in a couple of other sysfs
attribute routines. (Look at show_configuration_string() to see what I
mean.)
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
I can't stand text lines that wrap-around in my 80-column windows. This
patch (as589) makes cosmetic changes to a couple of source files.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This revised patch (as587b) improves the implementation of USB endpoint
sysfs files. Instead of storing a whole bunch of attributes for every
single endpoint, each endpoint now gets its own kobject and they can
share a static list of attributes. The number of extra fields added to
struct usb_host_endpoint has been reduced from 4 to 1.
The bEndpointAddress field is retained even though it is redundant (it
repeats the same information as the attributes' directory name). The
code avoids calling kobject_register, to prevent generating unwanted
hotplug events.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This should let us get rid of all of the different hooks in the USB core for
when something has changed.
Also, some other parts of the kernel have wanted to know this kind of
information at times.
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The way we're looking at USB suspend lately doesn't expect drivers to
call usb_suspend_device() or usb_resume_device() directly; that'll
be implicit when no interfaces are in use.
This patch removes those APIs from visibility outside usbcore.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
drivers/usb/core/hub.c | 12 ++++--------
drivers/usb/core/usb.h | 4 ++++
include/linux/usb.h | 5 -----
3 files changed, 8 insertions(+), 13 deletions(-)
This patch removes the extra usb_suspend_device() parameter. The original
reason to pass that parameter was so that this routine could suspend any
active children. A previous patch removed that functionality ... leaving
no reason to pass the parameter. A close analogy is pci_set_power_state,
which doesn't need a pm_message_t either.
On the internal code path that comes through the driver model, the parameter
is now used to distinguish cases where USB devices need to "freeze" but not
suspend. It also checks for an error case that's accessible through sysfs:
attempting to suspend a device before its interfaces (or for hubs, ports).
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
drivers/usb/core/hub.c | 34 +++++++++++++++++++++-------------
drivers/usb/core/usb.c | 23 +++++++++++++++++++++--
drivers/usb/host/ehci-hcd.c | 2 +-
drivers/usb/host/isp116x-hcd.c | 2 +-
drivers/usb/host/ohci-pci.c | 2 +-
include/linux/usb.h | 2 +-
6 files changed, 46 insertions(+), 19 deletions(-)
This patch adds endpoint information for both devices and interfaces to
sysfs. Previously it was only possible to get the endpoint information
from usbfs, and never possible to get any information on endpoint 0.
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
drivers/usb/core/sysfs.c | 195 ++++++++++++++++++++++++++++++++++++++++++++++-
include/linux/usb.h | 4
2 files changed, 197 insertions(+), 2 deletions(-)
29 July 2005, Cambridge, MA:
This afternoon Alan Stern submitted a patch to remove the URB_ASYNC_UNLINK
flag from the Linux kernel. Mr. Stern explained, "This flag is a relic
from an earlier, less-well-designed system. For over a year it hasn't
been used for anything other than printing warning messages."
An anonymous spokesman for the Linux kernel development community
commented, "This is exactly the sort of thing we see happening all the
time. As the kernel evolves, support for old techniques and old code can
be jettisoned and replaced by newer, better approaches. Proprietary
operating systems do not have the freedom or flexibility to change so
quickly."
Mr. Stern, a staff member at Harvard University's Rowland Institute who
works on Linux only as a hobby, noted that the patch (labelled as548) did
not update two files, keyspan.c and option.c, in the USB drivers' "serial"
subdirectory. "Those files need more extensive changes," he remarked.
"They examine the status field of several URBs at times when they're not
supposed to. That will need to be fixed before the URB_ASYNC_UNLINK flag
is removed."
Greg Kroah-Hartman, the kernel maintainer responsible for overseeing all
of Linux's USB drivers, did not respond to our inquiries or return our
calls. His only comment was "Applied, thanks."
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch introduces a /sys/class/usb_device/ class
where every connected usb-device will show up:
tree /sys/class/usb_device/
/sys/class/usb_device/
|-- usb1.1
| |-- dev
| `-- device -> ../../../devices/pci0000:00/0000:00:1d.0/usb1
|-- usb2.1
| |-- dev
| `-- device -> ../../../devices/pci0000:00/0000:00:1d.1/usb2
...
The presence of the "dev" file lets udev create real device nodes.
kay@pim:~/src/linux-2.6> tree /dev/bus/usb/
/dev/bus/usb/
|-- 1
| `-- 1
|-- 2
| `-- 1
...
udev rule:
SUBSYSTEM="usb_device", PROGRAM="/sbin/usb_device %k", NAME="%c"
(echo $1 | /bin/sed 's/usb\([0-9]*\)\.\([0-9]*\)/bus\/usb\/\1\/\2/')
This makes libusb pick up the real nodes instead of the mounted usbfs:
export USB_DEVFS_PATH=/dev/bus/usb
Background:
All this makes it possible to manage usb devices with udev instead of
the devfs solution. We are currently working on a pam_console/resmgr
replacement driven by udev and a pam-helper. It applies ACL's to device
nodes, which is required for modern desktop functionalty like
"Fast User Switching" or multiple local login support.
New patch with its own major. I've succesfully disabled usbfs and use real
nodes only on my box. With: "export USB_DEVFS_PATH=/dev/bus/usb" libusb picks
up the udev managed nodes instead of reading usbfs files.
This makes udev to provide symlinks for libusb to pick up:
SUBSYSTEM="usb_device", PROGRAM="/sbin/usbdevice %k", SYMLINK="%c"
/sbin/usbdevice:
#!/bin/sh
echo $1 | /bin/sed 's/usbdev\([0-9]*\)\.\([0-9]*\)/bus\/usb\/\1\/\2/'
Signed-off-by: Kay Sievers <kay.sievers@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Greg,
This patch fixes the kmalloc() flags argument type in USB
subsystem; hopefully all of its occurences. The patch was
made against patch-2.6.12-git2 from Jun 20.
Cleanup of flags for kmalloc() in USB subsystem.
Signed-off-by: Olav Kongas <ok@artecdesign.ee>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
On Wed, May 04, 2005 at 01:37:30PM -0700, David Brownell wrote:
> On Wednesday 04 May 2005 12:19 pm, Roman Kagan wrote:
> > struct urb {
> > /* private, usb core and host controller only fields in the urb */
> > ...
> > struct list_head urb_list; /* list pointer to all active urbs */
> > ...
> > };
> >
> > Is it safe to use it for driver's purposes when the driver owns the urb,
> > that is, starting from the completion routine until the urb is submitted
> > with usb_submit_urb()?
>
> Right now, it should be.
Great! FWIW I've briefly tested a modified version of usbatm using
the list head in struct urb instead of creating a wrapper struct, and I
haven't seen any failures yet. So I tend to believe that your "should
be" actually means "is" :)
> > If it is, can it be guaranteed in future, e.g.
> > by moving the list head into the public section of struct urb?
>
> In fact I'm not sure why it ever got called "private" to usbcore/hcds.
> I thought the idea was that it should be like urb->status, reserved for
> whoever controls the URB.
OK then how about the following (essentially documentation) patch?
Signed-off-by: Roman Kagan <rkagan@mail.ru>
Acked-by: David Brownell <david-b@pacbell.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
David Howells