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)
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 (as741) makes the non-hub parts of usbcore actually use the
autosuspend facilities added by an earlier patch.
Devices opened through usbfs are autoresumed and then
autosuspended upon close.
Likewise for usb-skeleton.
Devices are autoresumed for usb_set_configuration.
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 uses completion timeout instead of a timer to implement
a timeout when submitting an URB in usb_start_wait_urb().
It also fixes a small issue. With the previous code, if no timeout
happened and the URB's status was set to ECONNRESET value, the code
assumed wrongly that a timeout had occured.
Signed-off-by: Franck Bui-Huu <vagabon.xyz@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as703) improves the error handling when a Set-Configuration
request fails. The old interfaces are all unregistered before the
request is sent, and if the request fails then we don't know what config
the device is using. So it makes no sense to leave actconfig pointing
to the old configuration with its invalid interfaces.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
When trying to deconfigure a device via usb_set_configuration(dev, 0),
2.6.16-rc kernels after 55c527187c oops
with "Unable to handle NULL pointer dereference at...". This is due to
an unchecked dereference of cp in the power budget part.
Signed-off-by: Horst Schirmeier <horst@schirmeier.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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>
This patch (as621) fixes a local variable conflict I accidently
introduced into usb_set_configuration.
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 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>
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>
This patch (as588) fixes the way endpoint attribute files are registered
and unregistered. Now they will correctly track along with altsetting
changes. This fixes bugzilla entry #5467.
In a separate but related change, when a usb_reset_configuration call
fails, the device state is not changed to USB_STATE_ADDRESS. In the
first place, failure means that we don't know what the state is, not
that we know the device is unconfigured. In the second place, doing
this can potentially lead to a memory leak, since usbcore might not
realize there still is a current configuration that needs to be
destroyed.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Because there is no bulk_interrupt_message() routine and no
USBDEVFS_INTERRUPT ioctl, people have been forced to abuse the
usb_bulk_message() routine and USBDEVFS_BULK by using them for interrupt
transfers as well as bulk transfers.
This patch (as567) formalizes this practice and adds code to
usb_bulk_message() for detecting when the target is really an interrupt
endpoint. If it is, the routine submits an interrupt URB (using the
default interval) instead of a bulk URB. In theory this should help HCDs
that don't like it when people try to mix transfer types, queuing both
periodic and non-periodic types for the same endpoint.
Not fully tested -- I don't have any programs that use USBDEVFS_BULK for
interrupt transfers -- but it compiles okay and normal bulk messages work
as well as before.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
drivers/usb/core/message.c | 24 ++++++++++++++++++++----
1 file changed, 20 insertions(+), 4 deletions(-)
This updates the handling of power state for USB interfaces.
- Formalizes an existing invariant: interface "power state" is a boolean:
ON when I/O is allowed, and FREEZE otherwise. It does so by defining
some inlined helpers, then using them.
- Adds a useful invariant: the only interfaces marked active are those
bound to non-suspended drivers. Later patches build on this invariant.
- Simplifies the interface driver API (and removes some error paths) by
removing the requirement that they record power state changes during
suspend and resume callbacks. Now usbcore does that.
A few drivers were simplified to address that last change.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
drivers/usb/core/hub.c | 33 +++++++++------------
drivers/usb/core/message.c | 1
drivers/usb/core/usb.c | 65 +++++++++++++++++++++++++++++++++----------
drivers/usb/core/usb.h | 18 +++++++++++
drivers/usb/input/hid-core.c | 2 -
drivers/usb/misc/usbtest.c | 10 ------
drivers/usb/net/pegasus.c | 2 -
drivers/usb/net/usbnet.c | 2 -
8 files changed, 85 insertions(+), 48 deletions(-)
add the helper and use it instead of open coding the klist_node_attached() check
(which is a layering violation IMHO)
idea by Alan Stern.
Signed-off-by: Daniel Ritz <daniel.ritz@gmx.ch>
Cc: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Avoid an annoying message that can appear if devices are disconnected
in the middle of a USB scatterlist operation.
Message noted in http://bugzilla.kernel.org/show_bug.cgi?id=4373
(but the real issue there seems to be a SCSI level hang).
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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 handles a rarely-encountered failure mode in usbcore. It's
legal for device_add to fail (although now it happens even more rarely
than before since failure to bind a driver is no longer fatal). So when
we destroy the interfaces in a configuration, we shouldn't try to delete
ones which weren't successfully registered. Also, failure to register an
interface shouldn't be fatal either -- I think; you may disagree about
this part of the patch.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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>
This reverts a recent change to usb_set_interface(). The change worked
around a quirk in certain devices, but doing this in usbcore creates
needless regressions for other devices. More appropriate fixes won't
put such handling in usbcore.
Basically it's tricky to do a full software reset of USB device state, since
the devices don't all act the same. This adds a note to the kerneldoc for
the usb_reset_configuration() call to highlight the quirk this was working
around: endpoint data toggles not being reset.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
