ELAN's U132 is a USB to CardBus OHCI controller adapter,
designed specifically for CardBus 3G data cards to
function in machines without a CardBus slot.
The "ftdi-elan" module is a USB client driver, that detects
a supported CardBus OHCI controller plugged into the
U132 adapter and thereafter provides the conduit for
for access by the "u132-hcd" module.
The "u132-hcd" module is a (cut-down OHCI) host controller
that supports a single OHCI function of the CardBus
card inserted into the U132 adapter.
The problem with the initial implementation is that when
the CardBus card inserted into the U132 adapter has multiple
functions (and a CardBus card can support up to 4 functions),
it was the first function that was arbitrarily choosen.
The first batch of 3G cards tested, like the Merlin Qualcomm
V620, have two functions each supporting a seperate USB OHCI
host controller, of which it was that first function that is
wired up to the 3G modem.
Then along comes the Vodafone Mobile Connect 3G/GPRS data card,
aka "Option GT 3G Quad" as printed on it's rear or "Option N.V.
GlobeTrotter Fusion Quad Lite" as read with "lspci -v". And it
has the meaningful functionality in the second CardBus function.
That presents a problem because it was the "ftdi-elan" module
alone that knows how to communicate to the embedded CardBus slot
and the "u132-hcd" module alone that knows how to access the
pcmcia configuration and CardBus accessible memory space. And
of course, the information about attached (internally hardwired)
devices is contained within USB configuration embedded somewhere
within the CardBus card.
If only the "u132-hcd" module probe() interface could return a
result code that propagated back to the instigating function
platform_device_register() then the "ftdi-elan" module could
try an alternative CardBus function. However in spite of
the recent changes to the drivers/base/ routines that moved
device_attach() from bus_add_device() to bus_attach_device()
both of those routines lose the "failed to attach" 0 result
code and thus the calling routine, namely device_add() is
incapable of propaging the "failed to attach" condition back
to platform_device_add() and consequently back to the caller
of platform_device_register()
Experiments show that patching bus_attach_device() to return
ENODEV fails with the kernel locking up very early during
boot. But, however, if the patch is restricted to calls from
platform_device_add() then it does seem to work.
Unfortunately, until the kernel's drivers/base is properly
modified to propagate -ENODEV back to the caller of
platform_device_register(), it is necessary to "fix" the
"ftdi-elan" module by importing knowledge from the
"u132-hcd" module. This is the reason for the duplicated
functionality introduced in this patch.
Signed-off-by: Tony Olech <tony.olech@elandigitalsystems.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Conflicts:
drivers/infiniband/core/iwcm.c
drivers/net/chelsio/cxgb2.c
drivers/net/wireless/bcm43xx/bcm43xx_main.c
drivers/net/wireless/prism54/islpci_eth.c
drivers/usb/core/hub.h
drivers/usb/input/hid-core.c
net/core/netpoll.c
Fix up merge failures with Linus's head and fix new compilation failures.
Signed-Off-By: David Howells <dhowells@redhat.com>
* master.kernel.org:/pub/scm/linux/kernel/git/gregkh/usb-2.6: (103 commits)
usbcore: remove unused argument in autosuspend
USB: keep count of unsuspended children
USB hub: simplify remote-wakeup handling
USB: struct usb_device: change flag to bitflag
OHCI: make autostop conditional on CONFIG_PM
USB: Add autosuspend support to the hub driver
EHCI: Fix root-hub and port suspend/resume problems
USB: create a new thread for every USB device found during the probe sequence
USB: add driver for the USB debug devices
USB: added dynamic major number for USB endpoints
USB: pegasus error path not resetting task's state
USB: endianness fix for asix.c
USB: build the appledisplay driver
USB serial: replace kmalloc+memset with kzalloc
USB: hid-core: canonical defines for Apple USB device IDs
USB: idmouse cleanup
USB: make drivers/usb/core/driver.c:usb_device_match() static
USB: lh7a40x_udc remove double declaration
USB: pxa2xx_udc recognizes ixp425 rev b0 chip
usbtouchscreen: add support for DMC TSC-10/25 devices
...
This patch contains the following possible cleanups:
- make the needlessly global ftdi_release_platform_dev() static
- remove the unused usb_ftdi_elan_read_reg()
- proper prototypes for the following functions:
- usb_ftdi_elan_read_pcimem()
- usb_ftdi_elan_write_pcimem()
Note that the misplaced prototypes for the latter ones in
drivers/usb/host/u132-hcd.c were buggy. Depending on the calling
convention of the architecture calling one of them could have turned
your stack into garbage.
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch makes the needlessly global "u132_hcd_wait" static.
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Fix various .c/.h typos in comments (no code changes).
Signed-off-by: Matt LaPlante <kernel1@cyberdogtech.com>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
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 "u132-hcd" module is one half of the "driver" for
ELAN's U132 which is a USB to CardBus OHCI controller
adapter. This module needs the "ftdi-elan" module in
order to communicate to CardBus OHCI controller inserted
into the U132 adapter.
When the "ftdi-elan" module detects a supported CardBus
OHCI controller in the U132 adapter it loads this "u132-hcd"
module.
Upon a successful device probe() the single workqueue
is started up which does all the processing of commands
from the USB core that implement the host controller.
The workqueue maintains the urb queues and issues commands
via the functions exported by the "ftdi-elan" module. Each
such command will result in a callback.
Note that the "ftdi-elan" module is a USB client driver.
Note that this "u132-hcd" module is a (cut-down OHCI)
host controller.
Thus we have a topology with the parent of a host controller
being a USB client! This really stresses the USB subsystem
semaphore/mutex handling in the module removal.
Signed-off-by: Tony Olech <tony.olech@elandigitalsystems.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
