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>
Somewhere along the line, a variable in a USB-OTG codepath
stopped being used; this removes the relevant compiler warning.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch(as785) forces the PM core to resume a root hub after a
power loss during system sleep. If the root hub had been suspended
before the system sleep then normally the PM core would not resume it
afterward. Without this resume, various sorts of wakeup events (like
port change events) can get lost.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The patch removes unneeded casts for the following (void *) pointers:
- struct file: private
- struct urb: context
- struct usb_bus: hcpriv
- return value of kmalloc()
The patch also contains some whitespace cleanup in the relevant areas.
Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as740) removes the existing support for autosuspend of
root hubs. That support fit in rather awkwardly with the rest of
usbcore and it was used only by ohci-hcd. It won't be needed any more
since the hub driver will take care of autosuspending all hubs, root
or external.
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>
New code being pushed to linuxuwb.org requires this patch to connect
WUSB devices.
Signed-off-by: Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch teaches the USB stack handling of WUSB devices (those whose
speed is USB_SPEED_VARIABLE). For these devices, we need to set ep0's
maxpacketsize to 512 (even though the device descriptor reports it as
0xff).
New code being pushed to linuxuwb.org requires this patch to connect WUSB
devices.
Signed-off-by: Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch enables the USB stack to recognize WUSB devices (from a
WUSB HCD) and assigns them the proper speed setting
(USB_SPEED_VARIABLE).
1. Introduce usb_hcd->wireless to mark a host controller instance as
being wireless, and thus having wireless 'fake' ports.
[discarded previous model of using a reserved bit in the port_stat
struct to do this; thanks to Alan Stern for indicating the
proper way to do it].
2. Introduce hub.c:hub_is_wusb() that tests if a hub is a WUSB root
hub (WUSB doesn't have non-root hubs).
New code being pushed to linuxuwb.org requires this patch to connect WUSB
devices.
Signed-off-by: Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
We don't want khubd to start interfering in the device-resume process
merely because the PORT_STATUS_C_SUSPEND feature happens to be set.
Ports need to be marked as busy while a resume is taking place.
In addition, so long as ports are marked as busy, khubd won't be able to
clear their various status-change features. On an interrupt-driven root
hub this could lead to an interrupt storm. Root hub IRQs should not be
re-enabled until the busy_bits value is equal to 0.
This patch (as765) fixes these two potential problems.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as736) makes the hub driver more readable by improving the
usage of "#ifdef CONFIG_PM" and "#ifdef CONFIG_USB_SUSPEND".
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as734) rationalizes the various tests of device state and
power states. There are duplications and mistaken tests in several
places.
Perhaps the most interesting challenge is where the hub driver tests to
see that all the child devices are suspended before allowing itself to
be suspended. When CONFIG_USB_SUSPEND is set the test is
straightforward, since we expect that the children _will_ be suspended.
But when CONFIG_USB_SUSPEND isn't set, it's not so clear what should be
done. The code compromises by checking the child's
power.power_state.event field.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as733) fixes up the places where device states and power
states are set in usbcore. Right now things are duplicated or missing;
this should straighten things out.
The idea is that udev->state is USB_STATE_SUSPENDED exactly when the
device's upstream port has been suspended, whereas
udev->dev.power.power_state.event reflects the result of the last call
to the suspend/resume routines (which might not actually change the
device state, especially if CONFIG_USB_SUSPEND isn't set).
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as717b) removes the existing recursion in hub resume code:
Resuming a hub will no longer automatically resume the devices attached
to the hub.
At the same time, it adds one level of recursion: Suspending a USB
device will automatically suspend all the device's interfaces. Failure
at an intermediate stage will cause all the already-suspended interfaces
to be resumed. Attempts to suspend or resume an interface by itself will
do nothing, although they won't return an error. Thus the regular
system-suspend and system-resume procedures should continue to work as
before; only runtime PM will be affected.
The patch also removes the code that tests state of the interfaces
before suspending a device. It's no longer needed, since everything
gets suspended together.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as714b) makes usb_generic into a usb_device_driver capable
of being probed and unbound, just like other drivers. A fair amount of
the work that used to get done during discovery or removal of a USB
device have been moved to the probe and disconnect methods of
usb_generic: creating the sysfs attributes and selecting an initial
configuration. However the normal behavior should continue to be the
same as before.
We will now have the possibility of creating other USB device drivers,
They will assist with exporting devices to remote systems
(USB-over-TCPIP) or to paravirtual guest operating systems.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This revised patch (as715b) renames usb_suspend_device to
usb_port_suspend, usb_resume_device to usb_port_resume, and
finish_device_resume to finish_port_resume. There was no objection to
the original version of the patch so this should be okay to apply.
The revision was needed only because I have re-arranged the order of the
earlier patches.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as731) makes a couple of small fixes to the hub_port_resume
routine:
Don't return status >= 0 when an error occurs;
Clear the port-change-suspend status indicator after
resuming a device.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
finish_device_resume() in the hub driver isn't careful always to return
a negative code in all the error pathways. It also doesn't return 0 in
all the success pathways. This patch (as724) fixes the behavior.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as700) modifies the hub driver to take advantage of the new
usb_reset_composite_device API. The existing code had special-case
calls stuck into usb_reset_device, just before and after the reset.
With the new version there's no need for special-case stuff; it all
happens naturally in the form of pre_reset and post_reset notifications.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
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>
RNDIS devices don't get configured owing to a typo in
choose_configuration(). This patch from Giridhar Pemmasani fixes the
typo.
From: Giridhar Pemmasani <giri@lmc.cs.sunysb.edu>
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2.6.16 introduces USB power budgeting in the Linux kernel, and since then, a
fair number of users have observed that some of their devices no longer work in
unpowered hubs (this is not a bug, the devices claim that they need more than
100mA).
The very least we can do is print an informational message to the kernel log
when this happens, otherwise it is not at all clear why the device was not
accepted.
Signed-off-by: Daniel Drake <dsd@gentoo.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Some hubs claim not to support port-power switching, and right now the
hub driver believes them and does not enable power to their ports.
However it turns out that even though they don't actually switch power,
they do ignore all events on a port until told to turn on the power!
This problem has been reported by several users.
This revised patch (as672b) makes the hub driver always try to turn on
port power to all hubs, regardless of what the hub descriptor says. It
also adds a comment explaining the need for this.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The choose_configuration() routine contains code the determine the
device's power source, so that configurations requiring external power
can be ruled out if the device is running on bus power. Unfortunately
it turns out that some devices have errors in their config descriptors
and other devices don't like the GET_DEVICE_STATUS request.
Since that information wasn't used for anything else, this patch (as673)
removes the code, leaving only a comment. It fixes bugzilla entry
#6448.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
USB OTG devices are not required to support external hubs. This adds a
configuration option to disable that support.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
In a couple of places, usbcore assumes that a USB device configuration
will have a nonzero number of interfaces. Having no interfaces may or
may not be allowed by the USB spec; in any event we shouldn't die if we
encounter such a thing. This patch (as662) removes the assumptions.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as647) fixes a small error introduced by a recent change to
the USB core suspend/resume code.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This makes usbcore use the driver model wakeup flags for host controllers
and for their root hubs. Since previous patches have removed all users of
the HCD flags they replace, this converts the last users of those flags.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
the patch below converts a bunch of semaphores-used-as-mutex in the USB
code to mutexes
Signed-off-by: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as614) makes a small change to the part of the hub driver
responsible for remote wakeup of root hubs. When these wakeups occur
the driver is suspended, and in case the resume fails the driver should
remain suspended -- it shouldn't try to proceed with its normal
processing.
This will hardly ever matter in normal use, but it did crop up while I
was debugging a different problem.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
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>
The earlier USB locking updates didn't touch the suspend/resume
routines. They need updating as well, since now the caller holds the
device semaphore. This patch (as608) makes the necessary changes. It
also adds a line to store the correct power state when a device is
resumed, something which was unaccountably missing.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as606b) is an updated version of my earlier patch to
disconnect children from a hub device when the hub driver is unbound.
Thanks to the changes in the driver core locking, we now know that the
entire hub device (and not just the interface) is locked whenever the
hub driver's disconnect method runs. Hence it is safe to disconnect the
child device structures immediately instead of deferring the job.
The earlier version of the patch neglected to disable the hub's ports.
We don't want to forget that; otherwise we'd end up with live devices
using addresses that have been recycled. This update adds the necessary
code.
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 patch (as515b) adds a routine to usbcore to simplify handling of
host controllers that lost power or were reset during suspend/resume.
The new core routine marks all the child devices of the root hub as
NOTATTACHED and tells khubd to disconnect the device structures as soon
as possible.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This fixes some bugs in EHCI suspend/resume that joined us over the past
few releases (as usbcore, PCI, pmcore, and other components evolved):
- Removes suspend and resume recursion from the EHCI driver, getting
rid of the USB_SUSPEND special casing.
- Updates the wakeup mechanism to work again; there's a newish usbcore
call it needs to use.
- Provide simpler tests for "do we need to restart from scratch", to
address another case where PCI Vaux was lost. (In this case it was
restoring a swsusp snapshot, but there could be others.)
Un-exports a symbol that was temporarily exported.
A notable change from previous version is that this doesn't move
the spinlock init, so there's still a resume/reinit path bug.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This lets us remove a lot of code in the drivers that were all checking
the same thing. It also found some bugs in a few of the drivers, which
has been fixed up.
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
With CONFIG_PM=n:
drivers/built-in.o(.text+0x1098c): In function `hub_thread':
drivers/usb/core/hub.c:2673: undefined reference to `.dpm_runtime_resume'
drivers/built-in.o(.text+0x10998):drivers/usb/core/hub.c:2674: undefined reference to `.dpm_runtime_resume'
Please, never ever ever put extern decls into .c files. Use the darn header
files :(
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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>
This patch (as590) fixes up all the remaining places where usbcore can
use kzalloc rather than kmalloc/memset.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
David Howells