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 (as790b) adds "autostop" support to ohci-hcd: the driver
will automatically stop the host controller when no devices have been
connected for at least one second. This feature is useful when the
USB autosuspend facility isn't available, such as when
CONFIG_USB_SUSPEND hasn't been set.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
When ohci-hcd is shutting down (for rmmod or PC-card removal), there is
a window when the device is shut down, HC communication area (->hcca)
is freed, but the core has not called "free_irq" yet. If another device
triggers a shared interrupt in this window, we oops when trying to
access the freed ->hcca.
This patch removes the window by calling free_irq before ->hcca is freed.
The patch is tested at the PC hotplug test rig at Stratus, and with
rmmod by Rafael Wysocki.
Signed-off-by: Pete Zaitcev <zaitcev@redhat.com>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
If some problem occurs during ehci startup, for instance, request_irq fails,
echi hcd driver tries it best to cleanup, but fails to unregister reboot
notifier, which in turn leads to crash on reboot/poweroff.
The following patch resolves this problem by not using reboot notifiers
anymore, but instead making ehci/ohci driver get its own shutdown method. For
PCI, it is done through pci glue, for everything else through platform driver
glue.
One downside: sa1111 does not use platform driver stuff, and does not have its
own shutdown hook, so no 'shutdown' is called for it now. I'm not sure if it
is really necessary on that platform, though.
Signed-off-by: Aleks Gorelov <dared1st@yahoo.com>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
inlined is the patch that adds basic support for USB OHCI controller
support for PNX4008 Philips PNX4008 ARM board. Due to HW design, it
depends on I2C driver for PNX4008 which I've recetnly posted to LKML and
i2c at lm-sensors.
Signed-off-by: Vitaly Wool <vitalywool@gmail.com>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This teaches OHCI to use the root hub status change (RHSC) IRQ, bypassing
root hub timers most of the time and switching over to the "new" root hub
polling scheme. It's complicated by the fact that implementations of OHCI
trigger and ack that IRQ differently (the spec is vague there).
Avoiding root hub timers helps mechanisms like "dynamic tick" leave the
CPU in lowpower modes for longer intervals.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
OHCI updates for AT91 series processors:
- Get ready for at91sam926x processors (ARMv5tej not ARMv4t)
- Suspend/resume support now behaves properly
- In "standby" mode, OHCI can be a source of system wakeup events
(remote wakeup, device connect/disconnect, etc)
And minor cleanups.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Victor <andrew@sanpeople.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch adds OHCI glue bits for the USB host interface in the
Cirrus ep93xx (arm920t) CPU.
Signed-off-by: Lennert Buytenhek <buytenh@wantstofly.org>
Acked-by: David Brownell <david-b@pacbell.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
A loop on a power-lost resume path used the wrong index.
I suspect khubd has been working around such bugs.
Noticed by Andreas Mohr <andi@rhlx01.fht-esslingen.de>.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This makes OHCI use the driver model wakeup control bits for its root hub
(e.g. disable on amd756, because of chip erratum) and for the controller
itself. It no longer uses the hcd glue bits with those roles, and depends
on the previous patch making the root hub available earlier.
Note that on most platforms (boot code properly setting the RWC bit) this
gives a partial workaround for the way PCI isn't currently flagging devices
that support PME# signals. (Because of odd PCI init sequencing on PPC.)
That's because many OHCI controllers support "legacy PCI PM" ... without
involving any PCI PM capability.
USB wakeup from STR, if it works on your system, may still involve
tweaking things by hand in /proc/acpi/wakeup.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This adds support for OHCI on AT91rm9200 based boards.
Possibly of interest here is the way this uses <linux/clk.h> to
gate clocks on/off during system pm state transitions. That's
typical for non-PCI systems. Some can go further; Mini-A host
side connectors enable ID-pin sensing.
From: Andrew Victor <andrew@sanpeople.com>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
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 modifies the HCD builds to automatically "-DDEBUG" if
CONFIG_USB_DEBUG is selected. It's just a minor source code cleanup,
guaranteeing consistency.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch closes the IRQ race and makes various other OHCI & EHCI code
path safer vs. suspend/resume.
I've been able to (finally !) successfully suspend and resume various
Mac models, with or without USB mouse plugged, or plugging while asleep,
or unplugging while asleep etc... all without a crash.
Alan, please verify the UHCI bit I did, I only verified that it builds.
It's very simple so I wouldn't expect any issue there. If you aren't
confident, then just drop the hunks that change uhci-hcd.c
I also made the patch a little bit more "safer" by making sure the store
to the interrupt register that disables interrupts is not posted before
I set the flag and drop the spinlock.
Without this patch, you cannot reliably sleep/wakeup any recent Mac, and
I suspect PCs have some more sneaky issues too (they don't frankly crash
with machine checks because x86 tend to silently swallow PCI errors but
that won't last afaik, at least PCI Express will blow up in those
situations, but the USB code may still misbehave).
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This simplifies the OHCI root hub suspend logic:
- Uses new usbcore root hub calls to make autosuspend work again:
* Uses a newish usbcore root hub wakeup mechanism,
making requests to khubd not keventd.
* Uses an even newer sibling suspend hook.
- Expect someone always made usbcore call ohci_hub_suspend() before bus
glue fires; and that ohci_hub_resume() is only called after that bus
glue ran. Previously, only CONFIG_USB_SUSPEND promised those things.
(Includes updates to PCI and OMAP bus glue.)
- Handle a not-noticed-before special case during resume from one of
the swsusp snapshots when using "usb-handoff": the controller isn't
left in RESET state. (A bug to fix in the usb-handoff code...)
Also cleans up a minor debug printk glitch, and switches an mdelay over
to an msleep (how did that stick around for so long?).
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
drivers/usb/host/ohci-dbg.c | 4 ----
drivers/usb/host/ohci-hcd.c | 2 +-
drivers/usb/host/ohci-hub.c | 42 ++++++++++++------------------------------
drivers/usb/host/ohci-mem.c | 1 -
drivers/usb/host/ohci-omap.c | 36 ++++++++++++------------------------
drivers/usb/host/ohci-pci.c | 40 ++++++++--------------------------------
drivers/usb/host/ohci.h | 1 -
7 files changed, 33 insertions(+), 93 deletions(-)
This simplifies some of the PM-related #ifdeffing by recognizing
that USB_SUSPEND depends on PM. Also, OHCI drivers were often
testing for USB_SUSPEND when they should have tested just PM.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
drivers/usb/core/hcd.c | 2 ++
drivers/usb/host/ohci-hcd.c | 2 +-
drivers/usb/host/ohci-hub.c | 4 ++--
drivers/usb/host/ohci-omap.c | 2 +-
drivers/usb/host/ohci-pci.c | 2 +-
drivers/usb/host/ohci-ppc-soc.c | 4 ++--
drivers/usb/host/ohci-pxa27x.c | 2 +-
drivers/usb/host/ohci-s3c2410.c | 3 +--
drivers/usb/host/ohci-sa1111.c | 2 +-
9 files changed, 12 insertions(+), 11 deletions(-)
Some OHCI implementations have differences in the way the NDP register
(in roothub_a) reports the number of ports present. This patch allows the
platform specific code to optionally supply the number of ports. The
driver just reads the value at init (if not supplied) instead of reading
it every time its needed (except for an AMD756 bug workaround).
It also sets the value correctly for the ARM pxa27x architecture.
Signed-Off-By: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Evidently there are some boards which care a lot about this, but
as a rule it's been hard to notice.
OHCI_INTR_RD wasn't always cleared in the ohci irq handler. On some
systems this means certain remote wakeup scenarios could seem to hang
(in an interrupt storm, RD never clearing).
From: "William Morrow" <William.Morrow@amd.com>
Signed-off-by: Jordan Crouse <jordan.crouse@amd.com>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
USB (OHCI) Host driver for S3C2410/S3C2440 based systems
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
A patch re-organizing some parts of root hub initialization deleted the
code initializing the bus-neutral reboot/shutdown notifier for OHCI.
This patch just restores that deleted code.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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 patch changes the host controller drivers; they no longer need to
register their root hubs because usbcore will take care of it for them.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch changes the HCDs that used the old hub_set_power_budget call,
making them use the new hcd->power_budget field instead.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Acked-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Adds a reboot notifier to OHCI, mostly to benefit kexec; plus
minor #include tweaks.
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!
David Howells