linux-toradex.git/drivers/usb/core/devio.c, branch v2.6.19

usb devio: handle class_device_create() error

2006-10-17T21:46:32+00:00

This patch adds missing class_device_create() error check,
and makes notifier return NOTIFY_BAD.

Signed-off-by: Akinobu Mita 
Signed-off-by: Greg Kroah-Hartman

[PATCH] devio __user annotations

2006-10-10T22:37:21+00:00

Signed-off-by: Al Viro 
Signed-off-by: Linus Torvalds

IRQ: Maintain regs pointer globally rather than passing to IRQ handlers

2006-10-05T14:10:12+00:00

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 
(cherry picked from 1b16e7ac850969f38b375e511e3fa2f474a33867 commit)

[PATCH] usb: fixup usb so it uses struct pid

2006-10-02T14:57:15+00:00

The problem with remembering a user space process by its pid is that it is
possible that the process will exit, pid wrap around will occur.
Converting to a struct pid avoid that problem, and paves the way for
implementing a pid namespace.

Also since usb is the only user of kill_proc_info_as_uid rename
kill_proc_info_as_uid to kill_pid_info_as_uid and have the new version take
a struct pid.

Signed-off-by: Eric W. Biederman 
Acked-by: Greg Kroah-Hartman 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

USB: Remove unneeded void * casts in core files

2006-09-27T18:58:59+00:00

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 
Signed-off-by: Greg Kroah-Hartman

USB: fix __must_check warnings in drivers/usb/core/

2006-09-27T18:58:57+00:00

Signed-off-by: Greg Kroah-Hartman

usbcore: non-hub-specific uses of autosuspend

2006-09-27T18:58:57+00:00

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 
Signed-off-by: Greg Kroah-Hartman

USB: Make file operations structs in drivers/usb const.

2006-09-27T18:58:52+00:00

Making structs const prevents accidental bugs and with the proper debug
options they're protected against corruption.

Signed-off-by: Luiz Fernando N. Capitulino 
Signed-off-by: Greg Kroah-Hartman

usbfs: detect device unregistration

2006-09-27T18:58:49+00:00

This patch (as711b) is a revised version of an earlier submission.  It
modifies the usbfs code to detect when a device has been unregistered from
usbfs, even if the device is still connected.  Although this can't happen
now, it will be able to happen after the upcoming changes to usb_generic.

Nobody objected to this patch when it was submitted before, so it should
be okay to apply this version.  The revision is merely to take into
account the changes introduced by as723, which touches the same driver.


Signed-off-by: Alan Stern 
Signed-off-by: Greg Kroah-Hartman

usbfs: private mutex for open, release, and remove

2006-09-27T18:58:49+00:00

The usbfs code doesn't provide sufficient mutual exclusion among open,
release, and remove.  Release vs. remove is okay because they both
acquire the device lock, but open is not exclusive with either one.  All
three routines modify the udev->filelist linked list, so they must not
run concurrently.

Apparently someone gave this a minimum amount of thought in the past by
explicitly acquiring the BKL at the start of the usbdev_open routine.
Oddly enough, there's a comment pointing out that locking is unnecessary
because chrdev_open already has acquired the BKL.

But this ignores the point that the files in /proc/bus/usb/* are not
char device files; they are regular files and so they don't get any
special locking.  Furthermore it's necessary to acquire the same lock in
the release and remove routines, which the code does not do.

Yet another problem arises because the same file_operations structure is
accessible through both the /proc/bus/usb/* and /dev/usb/usbdev* file
nodes.  Even when one of them has been removed, it's still possible for
userspace to open the other.  So simple locking around the individual
remove routines is insufficient; we need to lock the entire
usb_notify_remove_device notifier chain.

Rather than rely on the BKL, this patch (as723) introduces a new private
mutex for the purpose.  Holding the BKL while invoking a notifier chain
doesn't seem like a good idea.


Signed-off-by: Alan Stern 
Signed-off-by: Greg Kroah-Hartman