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)
* Rougly half of callers already do it by not checking return value
* Code in drivers/acpi/osl.c does the following to be sure:
(void)kmem_cache_destroy(cache);
* Those who check it printk something, however, slab_error already printed
the name of failed cache.
* XFS BUGs on failed kmem_cache_destroy which is not the decision
low-level filesystem driver should make. Converted to ignore.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This teaches several USB host controller drivers to treat PRETHAW as a chip
reset since the controller, and all devices connected to it, are no longer in
states compatible with how the snapshotted suspend() left them.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as707) improves the FSBR operation in uhci-hcd by turning it
off more quickly when it isn't needed. FSBR puts a noticeable load on a
computer's PCI bus, so it should be disabled as soon as possible when it
isn't in use. The patch leaves it running for only 10 ms after the last
URB stops using it, on the theory that this should be long enough for a
driver to submit another URB if it wants keep FSBR going.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as706) removes the private hc_inaccessible flag from
uhci-hcd. It's not needed because it conveys exactly the same
information as the generic HCD_FLAG_HW_ACCESSIBLE bit.
In its place goes a new flag recording whether the controller is dead.
The new code allows a complete device reset to resurrect a dead
controller (although usbcore doesn't yet implement such a facility).
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as705) contains a small set of updates for uhci-hcd written
mostly by Dave Brownell:
* Root hub suspend messages come out labeled as root hub messages;
PCI messages should only come out when the pci device suspends.
* Rename the reset() method to better match its init() role
* Behave more like the other HCDs by returning -ESHUTDOWN for root-hub
suspend/resume errors.
* When an URB fails, associate the message with the usb device not
the host controller (it still hides endpoint and direction)
From: David Brownell <david-b@pacbell.net>
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as687) changes uhci-hcd to keep track of frame numbers as
full-sized integers rather than 11-bit values. This makes them a lot
easier to handle and makes it possible to schedule beyond a 2-second
window, should anyone ever want to do so.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as683) re-implements Full-Speed Bandwidth Reclamation (FSBR)
properly. It keeps track of which endpoint queues have advanced, and
when none have advanced for a sufficiently long time, FSBR is turned
off. The next TD on each of the non-moving queues is modified to
generate an interrupt on completion, so that FSBR can be re-enabled as
soon as the hardware starts to make some progress.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as682) gets rid of the TD-removal list in uhci-hcd. It is
no longer needed because now TDs are not freed until we know the
hardware isn't using them. It also simplifies the code for adding and
removing TDs to/from URBs.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
We could use the recently added PCI_CLASS_SERIAL_USB_UHCI,
PCI_CLASS_SERIAL_USB_OHCI and PCI_CLASS_SERIAL_USB_EHCI defines in
more places, for slightly shorter and clearer code.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Someone recently posted a bug report where it turned out that uhci-hcd
was disagreeing with the UHCI controller over whether or not a port was
suspended: The driver thought it wasn't and the hardware thought it was.
This patch (as665) fixes the problem and simplifies the driver by
removing the internal state-tracking completely. Now the driver just
asks the hardware whether a port is suspended.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch adds a header file with proper prototypes for two functions
in drivers/usb/host/pci-quirks.c.
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as626) makes some improvements to the debugging code in
uhci-hcd. The main change is that now the code won't get compiled if
CONFIG_USB_DEBUG isn't set. But there are other changes too, like
adding a missing .owner field and printing a debugging dump if the
controller dies.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
As part of reorienting uhci-hcd away from URBs and toward endpoint
queues, this patch (as625) eliminates the driver's main list of URBs.
The list wsa used mainly in checking for URB completions; now the driver
goes through the list of active endpoints and checks the members of the
queues.
As a side effect, I had to remove the code that looks for FSBR timeouts.
For now, FSBR will remain on so long as any URBs on a full-speed control
or bulk queue request it, even if the queue isn't advancing. A later
patch can add more intelligent handling. This isn't a huge drawback;
it's pretty rare for an URB to get stuck for more than a fraction of a
second. (And it will help the people trying to use those insane HP USB
devices.)
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as623) changes the uhci-hcd driver to make it use one QH per
device endpoint, instead of a QH per URB as it does now. Numerous areas
of the code are affected by this. For example, the distinction between
"queued" URBs and non-"queued" URBs no longer exists; all URBs belong to
a queue and some just happen to be at the queue's head.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as615b) edits a large number of comments in the uhci-hcd code,
mainly removing excess apostrophes.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as616) changed the uhci_explen macro in uhci-hcd.h so that
it now accepts the desired length, rather than length - 1 with special
handling for 0. This also fixes a minor bug that would show up only
when a driver submits a 0-length bulk URB.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
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 makes UHCI stop using the HCD glue wakeup flags to report whether
the controller can wake the system. The existing code was wrong anyway;
having a PCI PM capability doesn't imply it reports PME# is supported.
I skimmed Intel's ICH7 datasheet and that basically says the wakeup
signaling gets routed only through ACPI registers. (On the other hand,
many VIA chips provide the PCI PM capabilities...) I think that doing
this correctly with UHCI is going to require the ACPI folk to associate
the /proc/acpi/wakeup identifiers (and wakeup enable/disable flags)
with the relevant /sys/devices/pci*/... devices.
From: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as617) adds a couple of memory barriers that Ben H. forgot in
his recent suspend/resume fix.
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>
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>
Add .owner initialisation to the device drivers
in drivers/usb/host so that when built as module
the device_driver refers to the owning module
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as581) changes the assignments to hcd->state in the uhci-hcd
driver. It fixes part of bugzilla entry #5227. The problem was revealed
by David's large suite of USB suspend/resume patches; this patch should go
to Linus at the same time those do.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as580) is perhaps the only result from the long discussion I
had with David about his changes to the root-hub suspend/resume code. It
renames the hub_suspend and hub_resume methods in struct usb_hcd to
bus_suspend and bus_resume. These are more descriptive names, since the
methods really do suspend or resume an entire USB bus, and less likely to
be confused with the hub_suspend and hub_resume routines in hub.c.
It also takes David's advice about removing the layer of bus glue, where
those methods are called. And it implements a related change that David
made to the other HCDs but forgot to put into dummy_hcd.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as574) updates the PCI BIOS usb-handoff code for UHCI
controllers, making it work like the reset routines in uhci-hcd. This
allows uhci-hcd to drop its own routines in favor of the new ones
(code-sharing).
Once the patch is merged we can turn the usb-handoff option on
permanently, as far as UHCI is concerned. OHCI and EHCI may still have
some issues.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as563) splits the physical and logical framelist arrays in
uhci-hcd into two separate pieces. This will allow slightly better memory
utilization, since each piece is no larger than a single page whereas
before the whole thing was a little bigger than two pages. It also allows
the logical array to be allocated in non-DMA-coherent memory.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as562) removes from the uhci-hcd driver a few unused fields
and some unnecessary tests against NULL and assignments to NULL. In fact
it wasn't until fairly recently that the tests became unnecessary.
Before last winter it was possible that the driver's stop() routine would
get called even if the start() routine returned an error, but now that
can't happen. Hence there's no longer any need to check for partial
initialization.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as558) removes from the UHCI driver a kernel timer used for
checking Full Speed Bandwidth Reclamation (FSBR). The checking can be
done during normal root-hub polling; it doesn't need a separate timer.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch changes the way uhci-hcd detects valid ports. The
specification doesn't mention any way to find out how many ports a
controller has, so the driver has to use some heuristics, reading the port
status and control register and deciding whether the value makes sense.
With this patch the driver will recognize a typical failure mode (all bits
set to one) for nonexistent ports and won't assume there are always at
least 2 ports -- such an assumption seems silly if the heuristics have
already shown that the ports don't exist.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
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 simplifies the uhci-hcd driver by removing the device pointer
currently stored in the QH and TD structures. Those pointers weren't
being used for anything other than to increment the device's reference
count, which is unnecessary since the device is used only when an URB
completes, and outstanding URBs take their own reference to the device.
As a useful side effect, this change means that uhci-hcd no longer needs
to have the root-hub device available in the start routine.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
After all the discussion you might not be interested in this still, but
nevertheless here it is. This patch adds a shutdown method to the
uhci-hcd driver. Its prerequisite is the patch you wrote adding shutdown
support for PCI.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch improves the strategy uhci-hcd uses for performing controller
resets and checking whether they are needed.
The HCRESET command doesn't affect the Suspend, Resume,
or Reset bits in the port status & control registers, so
the driver must clear them by itself. This means the
code to figure out how many ports there are has to be moved
to an earlier spot in the driver.
The R/WC bits in the USBLEGSUP register can be set by the
hardware even in the absence of BIOS meddling with legacy
support features. Hence it's not a good idea to check them
while trying to determine whether the BIOS has altered the
controller's state.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch, which has as478b as a prerequisite, enables the uhci-hcd
driver to take advantage of root-hub IRQs rather than polling during the
time it is suspended. (Unfortunately the hardware doesn't support
port-change interrupts while the controller is running.) It also turns
off the driver's private timer while the controller is suspended, as it
isn't needed then. The combined elimination of polling interrupts and
timer interrupts ought to be enough to allow some systems to save a
noticeable amount of power while they are otherwise idle.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch tidies up a few loose ends left by the preceding patches.
It indicates the controller supports remote wakeup whenever the PM
capability is present -- which shouldn't cause any harm if the
assumption turns out to be wrong. It refuses to suspend the
controller if the root hub is still active, and it refuses to resume
the root hub if the controller is suspended. It adds checks for a
dead controller in several spots, and it adds memory barriers as
needed to insure that I/O operations are completed before moving on.
Actually I'm not certain the last part is being done correctly. With
code like this:
outw(..., ...);
mb();
udelay(5);
do we know for certain that the outw() will complete _before_ the
delay begins? If not, how should this be written?
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch implements (finally!) separate suspend and resume routines
for the root hub and the controller in the UHCI driver. It also
changes the sequence used to reset the controller during initial
probing, so as to preserve the existing state during a Resume-From-Disk.
(This new sequence is what should be used in the PCI Quirks code for
early USB handoffs, incidentally.) Lastly it adds a notion of the
controller being "inaccessible" while in a PCI low-power state, when
normal I/O operations shouldn't be allowed.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch starts making some serious changes to the UHCI driver.
There's a set of private states for the root hub, and the internal
routines for suspending and resuming work completely differently, with
transitions based on the new states. Now the driver distinguishes
between a privately auto-stopped state and a publicly suspended state,
and it will properly suspend controllers with broken resume-detect
interrupts instead of resetting them.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch makes a few small improvements in the UHCI driver. Some
code is moved between different source files and a more useful pointer
is passed to a callback routine.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch moves a few subroutines around in the uhci-hcd source file.
Nothing else is changed.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Get rid of a bunch of redundant NULL pointer checks in drivers/usb/*,
there's no need to check a pointer for NULL before calling kfree() on it.
Signed-off-by: Jesper Juhl <juhl-lkml@dif.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Index: gregkh-2.6/drivers/usb/class/audio.c
===================================================================
This patch includes minor "sparse -Wbitwise" updates for the PCI based
HCDs. Almost all of them involve just changing the second parameter of the
suspend() method to a pm_message_t ... the others relate to how the EHCI
code walks in-memory data structures. (There's a minor bug fixed there too
... affecting the big-endian sysfs async schedule dump.)
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Index: gregkh-2.6/drivers/usb/core/hcd.h
===================================================================
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!
