linux.git/drivers/usb/core/hcd.c, branch v2.6.27

USB: fix hcd interrupt disabling

2008-09-23T20:58:06+00:00

Commit de85422b94ddb23c021126815ea49414047c13dc, 'USB: fix interrupt
disabling for HCDs with shared interrupt handlers' changed usb_add_hcd()
to strip IRQF_DISABLED from irqflags prior to calling request_irq()
with the justification that such a removal was necessary for shared
interrupts to work properly.  Unfortunately, the change in that commit
unconditionally removes the IRQF_DISABLED flag, causing problems on
platforms that don't use a shared interrupt but require IRQF_DISABLED.
This change adds a check for IRQF_SHARED prior to removing the
IRQF_DISABLED flag.

Fixes the PS3 system startup hang reported with recent Fedora and
OpenSUSE kernels.

Note that this problem is hidden when CONFIG_LOCKDEP=y (ps3_defconfig),
as local_irq_enable_in_hardirq() is defined as a null statement for
that config.

CC: stable 
Signed-off-by: Geoff Levand 
Cc: Alan Stern 
Cc: Stefan Becker 
Signed-off-by: Greg Kroah-Hartman

USB: automatically enable RHSC interrupts

2008-08-21T17:26:38+00:00

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 
Signed-off-by: Greg Kroah-Hartman

USB: usb dev_name() instead of dev->bus_id

2008-07-21T22:15:46+00:00

The bus_id field is going away, use the dev_name() function instead.

Signed-off-by: Kay Sievers 
Signed-off-by: Greg Kroah-Hartman

USB: handle pci_name() being const

2008-07-21T22:15:46+00:00

This changes usb_create_hcd() to be able to handle the fact that
pci_name() has changed to a constant string.

Signed-off-by: Greg Kroah-Hartman

Revert "USB: don't explicitly reenable root-hub status interrupts"

2008-07-06T17:27:25+00:00

This reverts commit e872154921a6b5256a3c412dd69158ac0b135176.

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 
Acked-by: Alan Stern 
Acked-by: David Brownell 
Cc: Greg Kroah-Hartman 
Signed-off-by: Linus Torvalds

USB: fix interrupt disabling for HCDs with shared interrupt handlers

2008-07-04T01:20:37+00:00

USB: fix interrupt disabling for HCDs with shared interrupt handlers

As has been discussed several times on LKML, IRQF_SHARED | IRQF_DISABLED
doesn't work reliably, i.e. a shared interrupt handler CAN'T be certain to
be called with interrupts disabled. Most USB HCD handlers use IRQF_DISABLED
and therefore havoc can break out if they share their interrupt with a
handler that doesn't use it.

On my test machine the yenta_socket interrupt handler (no IRQF_DISABLED)
was registered before ehci_hcd and one uhci_hcd instance. Therefore all
usb_hcd_irq() invocations for ehci_hcd and for one uhci_hcd instance
happened with interrupts enabled. That led to random lockups as USB core
HCD functions that acquire the same spinlock could be called twice
from interrupt handlers.

This patch updates usb_hcd_irq() to always disable/restore interrupts.
usb_add_hcd() will silently remove any IRQF_DISABLED requested from HCD code.

Signed-off-by: Stefan Becker 
Cc: stable 
Acked-by: David Brownell 
Acked-by: Alan Stern 
Signed-off-by: Greg Kroah-Hartman

USB: Core: fix race in device_create

2008-05-20T20:31:56+00:00

There is a race from when a device is created with device_create() and
then the drvdata is set with a call to dev_set_drvdata() in which a
sysfs file could be open, yet the drvdata will be NULL, causing all
sorts of bad things to happen.

This patch fixes the problem by using the new function,
device_create_drvdata().

Cc: Kay Sievers 
Signed-off-by: Greg Kroah-Hartman

USB: don't explicitly reenable root-hub status interrupts

2008-04-25T04:16:53+00:00

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 
Signed-off-by: Greg Kroah-Hartman

USB: root hubs don't lie about their number of TTs

2008-04-25T04:16:48+00:00

Currently EHCI root hubs enumerate with a bDeviceProtocol code
indicating that they possess a Transaction Translator.  However the
vast majority of controllers do not; they rely on a companion
controller to handle full- and low-speed communications.  This patch
(as1064) changes the root-hub device descriptor to match the actual
situation.

Signed-off-by: Alan Stern 
Signed-off-by: Greg Kroah-Hartman

USB: fix comments of 2 functions in hcd.c

2008-04-25T04:16:45+00:00

Remove useless @type note for rh_string() and @r note for usb_hcd_irq()
since this two parameters were removed.

Signed-off-by: Ming Lei 
Signed-off-by: Greg Kroah-Hartman