linux-toradex.git/drivers/base, branch v3.2.10

regmap: Fix cache defaults initialization from raw cache defaults

2012-03-01T00:30:52+00:00

commit 61cddc57dc14a5dffa0921d9a24fd68edbb374ac upstream.

Currently registers with a value of 0 are ignored when initializing the register
defaults from raw defaults. This worked in the past, because registers without a
explicit default were assumed to have a default value of 0. This was changed in
commit b03622a8 ("regmap: Ensure rbtree syncs registers set to zero properly").
As a result registers, which have a raw default value of 0 are now assumed to
have no default. This again can result in unnecessary writes when syncing the
cache. It will also result in unnecessary reads for e.g. the first update
operation. In the case where readback is not possible this will even let the
update operation fail, if the register has not been written to before.

So this patch removes the check. Instead it adds a check to ignore raw defaults
for registers which are volatile, since those registers are not cached.

Signed-off-by: Lars-Peter Clausen 
Signed-off-by: Mark Brown 
Signed-off-by: Greg Kroah-Hartman

firmware: Fix an oops on reading fw_priv->fw in sysfs loading file

2012-01-12T19:29:17+00:00

commit eea915bb0d1358755f151eaefb8208a2d5f3e10c upstream.

This oops was reported recently:
firmware_loading_store+0xf9/0x17b
dev_attr_store+0x20/0x22
sysfs_write_file+0x101/0x134
vfs_write+0xac/0xf3
sys_write+0x4a/0x6e
system_call_fastpath+0x16/0x1b

The complete backtrace was unfortunately not captured, but details can be found
here:
https://bugzilla.redhat.com/show_bug.cgi?id=769920

The cause is fairly clear.

Its caused by the fact that firmware_loading_store has a case 0 in its
switch statement that reads and writes the fw_priv->fw poniter without the
protection of the fw_lock mutex.  since there is a window between the time that
_request_firmware sets fw_priv->fw to NULL and the time the corresponding sysfs
file is unregistered, its possible for a user space application to race in, and
write a zero to the loading file, causing a NULL dereference in
firmware_loading_store.  Fix it by extending the protection of the fw_lock mutex
to cover all of the firware_loading_store function.

Signed-off-by: Neil Horman 
Signed-off-by: Greg Kroah-Hartman

PM / Driver core: leave runtime PM enabled during system shutdown

2011-12-07T21:26:56+00:00

Disabling all runtime PM during system shutdown turns out not to be a
good idea, because some devices may need to be woken up from a
low-power state at that time.

The whole point of disabling runtime PM for system shutdown was to
prevent untimely runtime-suspend method calls.  This patch (as1504)
accomplishes the same result by incrementing the usage count for each
device and waiting for ongoing runtime-PM callbacks to finish.  This
is what we already do during system suspend and hibernation, which
makes sense since the shutdown method is pretty much a legacy analog
of the pm->poweroff method.

This fixes a recent regression on some OMAP systems introduced by
commit af8db1508f2c9f3b6e633e2d2d906c6557c617f9 (PM / driver core:
disable device's runtime PM during shutdown).

Reported-and-tested-by: NeilBrown 
Signed-off-by: Alan Stern 
Acked-by: Greg Kroah-Hartman 
Signed-off-by: Rafael J. Wysocki

Merge branch 'driver-core-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

2011-11-22T04:36:26+00:00

* 'driver-core-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core:
  drivers/base/node.c: fix compilation error with older versions of gcc
  uio: documentation fixups
  device.h: Fix struct member documentation

drivers/base/node.c: fix compilation error with older versions of gcc

2011-11-18T18:39:24+00:00

Patch to fix the error message "directives may not be used inside a macro
argument" which appears when the kernel is compiled for the cris architecture.

Signed-off-by: Claudio Scordino 
Acked-by: David Rientjes 
Cc: stable 
Signed-off-by: Greg Kroah-Hartman

PM Sleep: Do not extend wakeup paths to devices with ignore_children set

2011-11-17T20:39:33+00:00

Commit 4ca46ff3e0d8c234cb40ebb6457653b59584426c (PM / Sleep: Mark
devices involved in wakeup signaling during suspend) introduced
the power.wakeup_path field in struct dev_pm_info to mark devices
whose children are enabled to wake up the system from sleep states,
so that power domains containing the parents that provide their
children with wakeup power and/or relay their wakeup signals are not
turned off.  Unfortunately, that introduced a PM regression on SH7372
whose power consumption in the system "memory sleep" state increased
as a result of it, because it prevented the power domain containing
the I2C controller from being turned off when some children of that
controller were enabled to wake up the system, although the
controller was not necessary for them to signal wakeup.

To fix this issue use the observation that devices whose
power.ignore_children flag is set for runtime PM should be treated
analogously during system suspend.  Namely, they shouldn't be
included in wakeup paths going through their children.  Since the
SH7372 I2C controller's power.ignore_children flag is set, doing so
will restore the previous behavior of that SOC.

Signed-off-by: Rafael J. Wysocki 
Acked-by: Greg Kroah-Hartman

PM / driver core: disable device's runtime PM during shutdown

2011-11-15T20:52:29+00:00

There may be an issue when the user issue "reboot/shutdown" command, then
the device has shut down its hardware, after that, this runtime-pm featured
device's driver will probably be scheduled to do its suspend routine,
and at its suspend routine, it may access hardware, but the device has
already shutdown physically, then the system hang may be occurred.

I ran out this issue using an auto-suspend supported USB devices, like
3G modem, keyboard. The usb runtime suspend routine may be scheduled
after the usb controller has been shut down, and the usb runtime suspend
routine will try to suspend its roothub(controller), it will access
register, then the system hang occurs as the controller is shutdown.

Signed-off-by: Peter Chen 
Acked-by: Ming Lei 
Acked-by: Greg Kroah-Hartman 
Cc: stable@kernel.org
Signed-off-by: Rafael J. Wysocki

PM / QoS: Properly use the WARN() macro in dev_pm_qos_add_request()

2011-11-09T23:44:18+00:00

Make dev_pm_qos_add_request() use WARN() in a better way and do not hardcode
the function's name into the message (use __func__ instead).

Signed-off-by: Guennadi Liakhovetski 
Signed-off-by: Rafael J. Wysocki

PM / Clocks: Only disable enabled clocks in pm_clk_suspend()

2011-11-09T23:44:10+00:00

Refrain from running clk_disable() on clocks that
have not been enabled. A typical case when this can
happen is during Suspend-to-RAM for devices that have
no driver associated with them. In such case the clock
may be in default ACQUIRED state.

Without this patch the sh7372 Mackerel board crashes
in __clk_disable() during Suspend-to-RAM with:
"Trying to disable clock 0xdeadbeef with 0 usecount"
This happens for the CEU device which is added during
boot. The test case has no CEU driver included in the
kernel configuration. Needed for v3.2-rc1.

Signed-off-by: Magnus Damm 
Signed-off-by: Rafael J. Wysocki

PM / OPP: Use ERR_CAST instead of ERR_PTR(PTR_ERR())

2011-11-08T21:34:00+00:00

Use ERR_CAST inlined function instead of ERR_PTR(PTR_ERR(...))

[The semantic patch that makes this change is available
 in scripts/coccinelle/api/err_cast.cocci.

 More information about semantic patching is available at
 http://coccinelle.lip6.fr/]

Signed-off-by: Thomas Meyer 
Signed-off-by: Rafael J. Wysocki