This uses the USB busy mechanism for aggessive autosuspend of USB
HID devices. It autosuspends all opened devices supporting remote wakeup
after a timeout unless

- output is being done to the device
- a key is being held down (remote wakeup isn't triggered upon key release)
- LED(s) are lit
- hiddev is opened

As in the current driver closed devices will be autosuspended even if they
don't support remote wakeup.

The patch is quite large because output to devices is done in hard interrupt
context meaning a lot a queuing and locking had to be touched. The LED stuff
has been solved by means of a simple counter. Additions to the generic HID code
could be avoided. In addition it now covers hidraw. It contains an embryonic
version of an API to let the generic HID code tell the lower levels which
capabilities with respect to power management are needed.
Signed-off-by: NOliver Neukum <oneukum@suse.de>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

We can't return immediately because lock_kernel() is held.
Signed-off-by: NDan Carpenter <error27@gmail.com>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

The hidraw subsystem has a bug that prevents the close syscall from ever
reaching the low level driver, leading to a resource leak. Fix by replacing
postdecrement with predecrement.
Signed-off-by: NOliver Neukum <oneukum@suse.de>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

We need to properly set parent of the hidraw device (which is the
corresponding physical device itself) in order to hidraw devices not
end up under virtual device tree.
Reported-by: NKay Sievers <kay.sievers@vrfy.org>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

The hiddev interface provides ioctl() calls which can be used
to obtain phys and raw name of the underlying device.

Add the corresponding support also into hidraw.
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

As open needs to sleep hidraw was wrong to call it with a spinlock held.
Furthermore, open can of course fail which needs to be handled.
Signed-off-by: NOliver Neukum <oneukum@suse.de>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

Add omitted unlock_kernel() to hidraw_ioctl().
Added in 979c407e
(HID: Push down BKL into ioctl handler in hidraw).

Corresponing sparse warning:
drivers/hid/hidraw.c:267:9: warning: context imbalance in 'hidraw_ioctl': wrong count at exit
drivers/hid/hidraw.c:267:9:    context 'kernel_lock': wanted 0, got 1
Signed-off-by: NJiri Slaby <jirislaby@gmail.com>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

hidraw_exit() marked as __exit is called from __init function
from HID core. Remove the section placement from that function.
Reported-by: NGeert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: NJiri Slaby <jirislaby@gmail.com>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

Now that device_create() has been audited, rename things back to the
original call to be sane.
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

The bound check on the buffer length

	if (count > HID_MIN_BUFFER_SIZE)

is of course incorrent, the proper check is

	if (count > HID_MAX_BUFFER_SIZE)

Fix it.
Reported-by: NJerry Ryle <jerry@mindtribe.com>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

Next step for complete hid bus, this patch includes:
- call parser either from probe or from hid-core if there is no probe.
- add ll_driver structure and centralize some stuff there (open, close...)
- split and merge usb_hid_configure and hid_probe into several functions
  to allow hooks/fixes between them
Signed-off-by: NJiri Slaby <jslaby@suse.cz>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

hidraw_release() forgot to free the linked list structure, causing memory
leak.
Reported-by: NJuan Marcos Diez Esteban <juan_m_diez@yahoo.es>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

In this case I simply wrapped it as code review suggests the locking
already terminally broken and I didn't want to make it first. See added
comment
Signed-off-by: NAlan Cox <alan@redhat.com>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

device_create() is race-prone, so use the race-free
device_create_drvdata() instead as device_create() is going away.
Signed-off-by: NJiri Kosina <jkosina@suse.cz>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Signed-off-by: NJonathan Corbet <corbet@lwn.net>

The task_struct->pid member is going to be deprecated, so start
using the helpers (task_pid_nr/task_pid_vnr/task_pid_nr_ns) in
the kernel.

The first thing to start with is the pid, printed to dmesg - in
this case we may safely use task_pid_nr(). Besides, printks produce
more (much more) than a half of all the explicit pid usage.

[akpm@linux-foundation.org: git-drm went and changed lots of stuff]
Signed-off-by: NPavel Emelyanov <xemul@openvz.org>
Cc: Dave Airlie <airlied@linux.ie>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Fix bogus copying of data into userspace when HIDIOCGRDESC is issued.
HID-transport layer makes sure that dev->hid->rdesc is not larger than
HID_MAX_DESCRIPTOR_SIZE.
Noticed-by: NAl Viro <viro@ftp.linux.org.uk>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

It looks like hidraw_connect() is leaking memory in case of failure.
Also it should return -ENOMEM when kzalloc fails.
Signed-off-by: NMariusz Kozlowski <m.kozlowski@tuxland.pl>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

hidraw is an interface that is going to obsolete hiddev one
day.

Many userland applications are using libusb instead of using
kernel-provided hiddev interface. This is caused by various
reasons - the HID parser in kernel doesn't handle all the
HID hardware on the planet properly, some devices might require
its own specific quirks/drivers, etc.

hiddev interface tries to do its best to parse all the received
reports properly, and presents only parsed usages into userspace.
This is however often not enough, and that's the reason why
many userland applications just don't use hiddev at all, and
rather use libusb to read raw USB events and process them on
their own.

Another drawback of hiddev is that it is USB-specific.

hidraw interface provides userspace readers with really raw HID
reports, no matter what the low-level transport layer is (USB/BT),
and gives the userland applications all the freedom to process
the HID reports in a way they wish to.
Signed-off-by: NJiri Kosina <jkosina@suse.cz>