This patch (as1069c) changes the way OHCI root-hub status-change
interrupts are enabled. Currently a special HCD method,
hub_irq_enable(), is called when the hub driver is finished using a
root hub. This approach turns out to be subject to races, resulting
in unnecessary polling.
The patch does away with the method entirely. Instead, the driver
automatically enables the RHSC interrupt when no more status changes
are present. This scheme is safe with controllers using
level-triggered semantics for their interrupt flags.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as1114) fixes a problem that was revealed by an earlier
patch (as1069b). Some broken controllers seem never to turn off their
RHCS interrupt status bit, even when told to do so. As a result they
generate an interrupt storm and hang the system.
The patch avoids enabling RHSC interrupt requests when the RHCS status
bit is already set. This should have no adverse affects on normal
controllers, since they won't set the status bit until a root-hub
status change actually occurs, in which case we wouldn't enable RHSC
interrupt requests anyway -- we would wait until the status change had
been processed and cleared.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Tested by: Andrey Borzenkov <arvidjaar@mail.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This reverts commit e872154921.
Andrey Borzenkov reports that it resulted in a totally hung machine for
him when loading the OHCI driver. Extensive netconsole capture with
SysRq output shows that modprobe gets stuck in ohci_hub_status_data()
when probing and enabling the OHCI controller, see for example
http://lkml.org/lkml/2008/7/5/236
for an analysis.
The problem appears to be an interrupt flood triggered by the commit
that gets reverted, and Andrey confirmed that the revert makes things
work for him again.
Reported-and-tested-by: Andrey Borzenkov <arvidjaar@mail.ru>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Acked-by: David Brownell <david-b@pacbell.net>
Cc: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The patch (as1086) works around a bogus "uninitialized variable"
warning generated by some versions of GCC.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as1069b) changes the way OHCI root-hub status-change
interrupts are enabled. Currently a special HCD method,
hub_irq_enable(), is called when the hub driver is finished using a
root hub. This approach turns out to be subject to races, resulting
in unnecessary polling.
The patch does away with the method entirely. Instead, the driver
automatically enables the RHSC interrupt when no more status changes
are present. This scheme is safe with controllers using
level-triggered semantics for their interrupt flags.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as1068b) disables the RD interrupt flag when an OHCI root
hub is suspended with remote wakeup disabled. Although the spec
clearly states that this flag permits the controller to issue an
interrupt when a resume request from downstream is detected and not
when a local status change occurs, some controllers mistakenly use it
for both types of event.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
When a USB device is suspended, whether or not it is enabled for
remote wakeup depends on the device_may_wakeup() setting. The setting
is then saved in the do_remote_wakeup flag.
Later on, however, the device_may_wakeup() value can change because of
user activity. So when testing whether a suspended device is or
should be enabled for remote wakeup, we should always test
do_remote_wakeup instead of device_may_wakeup(). This patch (as1076)
makes that change for root hubs in several places.
The patch also adjusts uhci-hcd so that when an autostopped controller
is suspended, the remote wakeup setting agrees with the value recorded
in the root hub's do_remote_wakeup flag.
And the patch adjusts ehci-hcd so that wakeup events on selectively
suspended ports (i.e., the bus itself isn't suspended) don't turn on
the PME# wakeup signal.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Drivers in the ohci-hcd family should perform certain tasks whenever
their controller device is resumed. These include checking for loss
of power during suspend, turning on port power, and enabling interrupt
requests.
Until now these jobs have been carried out when the root hub is
resumed, not when the controller is. Many drivers work around the
resulting awkwardness by automatically resuming their root hub
whenever the controller is resumed. But this is wasteful and
unnecessary.
To simplify the situation, this patch (as1066) adds a new core
routine, ohci_finish_controller_resume(), which can be used by all the
OHCI-variant drivers. They can call the new routine instead of
resuming their root hubs. And ohci-pci.c can call it instead of using
its own special-purpose handler.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This limits how long the OHCI port reset loop waits for the hardware
to do its job, if the controller either (a) dies, or (b) can't finish
the reset. Such limits are always a good idea.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch fixes a silicon bug in some NEC OHCI chips. The bug appears
at random times and is very, very difficult to reproduce. Without the
following patch, Linux would shut the chip and its associated devices
down. In Apple PowerBooks this leads to an unusable keyboard and mouse
(SSH still working). The idea of restarting the chip is taken from
public Darwin code.
Signed-off-by: Michael Hanselmann <linux-kernel@hansmi.ch>
Cc: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as901) fixes an oversight in ohci-hcd. The
hub_status_data routine must not try to access the controller's
memory-mapped registers if the controller is in a low-power state;
such attempts will cause a crash on some architectures (such as PPC).
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
I have found a problem where the root_port_reset() goes into an infinite
loop and stalls the kernel.
This happens when a hardware fault inside the machine occurs during a small
timing window. In case of USB device connection, if a USB device responds to
hcd_submit_urb(), and later the controller fails before root_port_reset(),
root_port_reset() will loop infinitely because ohci_readl() will always
return "-1". Such a failure can include ejecting a CardBus OHCI controller.
The probability of this problem is low, but it will increase if PnP type
usage is frequent. The attached patch can solve this problem and I believe
that it is better to fix this problem.
Signed-off-by: Takamasa Ohtake <ohtake-txa@necst.nec.co.jp>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This is an OHCI cleanup patch ... it removes a lot of erroneous whitespace
(space before tab, at end of line) as well as the obsolete inline changelog.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Unlike UHCI, OHCI does not exert any DMA load on the system when no
devices are connected. Consequently there is no advantage to doing
an autostop other than the power savings, so we shouldn't compile the
necessary code unless CONFIG_PM is enabled.
This patch (as820) makes the root-hub suspend and resume routines
conditional on CONFIG_PM. It also prevents autostop from activating
if the device_may_wakeup flag isn't set; some people use this flag to
alert the driver about Resume-Detect bugs in the hardware.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
All the other root-hub suspend or resume log messages, in ohci-hcd or
any of the other host controller drivers, use the debug priority
level. This patch (as815) makes the one single exception behave like
all the rest.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as811) removes some stale testing code from the root-hub
resume routine in ohci-hcd. It also adds a spin_lock_irq() call that
inadvertently got left out of an error pathway.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as808b) moves the Root Hub Status Change interrupt-disable
code in ohci-hcd back into the interrupt handler proper, to avoid the
chance of adverse interactions with mediocre hardware implementations.
It also deletes the root-hub status timer from within the interrupt-enable
routine. There's no need to poll for status any more once interrupts are
re-enabled.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as806) fixes a compiler warning when ohci-hcd is built
with CONFIG_PM turned off.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
When a suspended OHCI controller sees a port's status change, it sets
both the Root-Hub-Status-Change and the Resume-Detect bits in the
Interrupt Status register. Processing both these bits, the driver
tries to resume the root hub twice!
This patch (as807) fixes the bug by ignoring RD if RHSC is set. It
also prints a slightly more informative log message when a
remote-wakeup event occurs.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as822) prevents the OHCI autostop mechanism from kicking in
if the root hub is not able or not allowed to issue wakeup requests.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.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)
Thanks to Andrew for the original patch for this.
I need to upgrade my version of gcc to catch these things...
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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>
The autosuspend technique used by ohci-hcd doesn't mesh well with the
newer USB core autosuspend code. This patch (as789) removes ohci-hcd's
autosuspend support. Now the driver will be usable, but it won't
automatically go into a low-power state when no devices are connected.
That's for a later patch.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as740) removes the existing support for autosuspend of
root hubs. That support fit in rather awkwardly with the rest of
usbcore and it was used only by ohci-hcd. It won't be needed any more
since the hub driver will take care of autosuspending all hubs, root
or external.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
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>
I noticed this while debugging something unrelated on
sparc64.
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: David Brownell <david-b@pacbell.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 patch (as605) removes the private udev->serialize semaphore,
relying instead on the locking provided by the embedded struct device's
semaphore. The changes are confined to the core, except that the
usb_trylock_device routine now uses the return convention of
down_trylock rather than down_read_trylock (they return opposite values
for no good reason).
A couple of other associated changes are included as well:
Now that we aren't concerned about HCDs that avoid using the
hcd glue layer, usb_disconnect no longer needs to acquire the
usb_bus_lock -- that can be done by usb_remove_hcd where it
belongs.
Devices aren't locked over the same scope of code in
usb_new_device and hub_port_connect_change as they used to be.
This shouldn't cause any trouble.
Along with the preceding driver core patch, this needs a lot of testing.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
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 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 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>
The length of the array desc->bitmap is 3, and not 4:
Definitions involved:
In drivers/usb/core/hcd.h
464 #define bitmap DeviceRemovable
In drivers/usb/host/ohci-hub.c
395 struct usb_hub_descriptor *desc
In drivers/usb/core/hub.h
130 struct usb_hub_descriptor {
131 __u8 bDescLength;
132 __u8 bDescriptorType;
133 __u8 bNbrPorts;
134 __u16 wHubCharacteristics;
135 __u8 bPwrOn2PwrGood;
136 __u8 bHubContrCurrent;
137 /* add 1 bit for hub status change; round to bytes */
138 __u8 DeviceRemovable[(USB_MAXCHILDREN + 1 + 7) / 8];
139 __u8 PortPwrCtrlMask[(USB_MAXCHILDREN + 1 + 7) / 8];
140 } __attribute__ ((packed));
In include/linux/usb.h
306 #define USB_MAXCHILDREN (16)
This defect was found automatically by Coverity Prevent, a static analysis
tool.
(akpm: this code should be shot. Field `bitmap' doesn't exist in struct
usb_hub_descriptor. And this .c file is #included in
drivers/usb/host/ohci-hcd.c, and someone somewhere #defines `bitmap' to
`DeviceRemovable'.
>From a maintainability POV it would be better to memset the whole array
beforehand - I changed the patch to do that)
Signed-off-by: Zaur Kambarov <zkambarov@coverity.com>
Cc: <linux-usb-devel@lists.sourceforge.net?
Signed-off-by: Andrew Morton <akpm@osdl.org>
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!
Alan Stern