Commit graph

315807 commits

Author SHA1 Message Date
Guennadi Liakhovetski
02cb3221d5 mmc: tmio: support caps2 flags
Allow tmio mmc glue drivers to pass mmc_host::caps2 flags down to
the mmc layer.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Chris Ball <cjb@laptop.org>
2012-07-21 00:02:18 -04:00
Guennadi Liakhovetski
5aa7dad305 mmc: core: add WP pin handler to slot functions
Card Write-Protect pin is often implemented, using a GPIO, which makes
it simple to provide a generic handler for it.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Chris Ball <cjb@laptop.org>
2012-07-21 00:02:18 -04:00
Guennadi Liakhovetski
a7d1a1ebd8 mmc: core: convert slot functions to managed allocation
This prepares for the addition of further slot functions.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Chris Ball <cjb@laptop.org>
2012-07-21 00:02:17 -04:00
Guennadi Liakhovetski
befe4048d8 mmc: add CD GPIO polling support to slot functions
A simple extension of mmc slot functions add support for CD GPIO polling
for cases where the GPIO cannot produce interrupts, or where this is not
desired for some reason.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Chris Ball <cjb@laptop.org>
2012-07-21 00:02:17 -04:00
Guennadi Liakhovetski
5c08d7fae0 mmc: add two capability flags for CD and WP signal polarity
To handle CD and WP SD/MMC slot pins we need generic flags to specify their
polarity.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Chris Ball <cjb@laptop.org>
2012-07-21 00:02:16 -04:00
Guennadi Liakhovetski
27410ee7e3 mmc: core: use a more generic name for slot function types and fields
struct mmc_host::hotplug is becoming a generic hook for slot functions.
Rename it accordingly.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Chris Ball <cjb@laptop.org>
2012-07-21 00:02:16 -04:00
Guennadi Liakhovetski
7d17baa05d mmc: sh_mmcif: add regulator support
Add regulator support to the sh_mmcif driver, but also preserve the current
power-callback.

Also note, that the card power is not switched off during clock gating
periods, hence there's no need to power it on every time the card is
re-activated.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Reviwed-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Reviewed-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Chris Ball <cjb@laptop.org>
2012-07-21 00:02:15 -04:00
Guennadi Liakhovetski
e2ee996eaa mmc: sh_mmcif: remove redundant .down_pwr() callback
From the original version of sh_mmcif the .set_pwr() callback has only been
used to turn the card's power on, and the .down_pwr() callback has been
used to turn it off. .set_pwr() can be used for both these tasks, which is
also how it is implemented by the only user of this API: the SH7724 ecovec
board.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Reviewed-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Chris Ball <cjb@laptop.org>
2012-07-21 00:02:14 -04:00
Guennadi Liakhovetski
a660926710 mmc: sh_mmcif: re-read the clock frequency every time it is turned on
With aggressive clock gating the clock can be disabled during interface
inactivity. During this time its frequency can be changed by another its
user. Therefore when the interface is activated again and the clock is
re-enabled, its frequency has to be re-read.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Reviewed-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Chris Ball <cjb@laptop.org>
2012-07-21 00:02:14 -04:00
Guennadi Liakhovetski
b289174ff7 mmc: sh_mmcif: fix clock management
Regardless of whether the MMC bus clock is the same as the PM clock on
this specific interface, it has to be managed separately. Its proper
management should also include enabling and disabling of the clock,
whenever the interface is becoming active or going idle respectively.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Reviewed-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Chris Ball <cjb@laptop.org>
2012-07-21 00:02:13 -04:00
Guennadi Liakhovetski
e1aae2eb3f mmc: sh_mmcif: simplify and use meaningful label names in error-handling
A check for NULL platform data can be conveniently made in the very
beginning of probing. Replace numbered error-handling labels in .probe()
with meaningful names to make any future reorganisation simpler.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Reviewed-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Chris Ball <cjb@laptop.org>
2012-07-21 00:02:13 -04:00
Guennadi Liakhovetski
944640d0ff mmc: tmio: remove a duplicated comment line
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Chris Ball <cjb@laptop.org>
2012-07-21 00:02:12 -04:00
Guennadi Liakhovetski
71da63e767 mmc: sdhi: do not install dummy callbacks
Currently the SDHI glue for the TMIO MMC driver installs dummy .get_cd() and
.set_pwr() callbacks even if the platform didn't supply them. This is not
necessary, since the TMIO MMC driver itself checks for NULL callbacks. This
is also dubious if the platform provides a regulator for SD-card power
switching. It is better to only install those callbacks, if they are really
provided by the platform.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Chris Ball <cjb@laptop.org>
2012-07-21 00:02:11 -04:00
Guennadi Liakhovetski
b958a67c6b mmc: tmio: add regulator support
Currently the TMIO MMC driver derives the OCR mask from the platform data
and uses a platform callback to turn card power on and off. This patch adds
regulator support to the driver.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Cc: Liam Girdwood <lrg@ti.com>
Cc: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
2012-07-21 00:02:11 -04:00
Guennadi Liakhovetski
56c4928793 mmc: sdhi: implement tmio-mmc clock enable-update and disable callbacks
Instead of delivering one static clock frequency value, read from the
hardware during probing, enable the tmio-mmc driver to re-read the
frequency dynamically.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Chris Ball <cjb@laptop.org>
2012-07-21 00:02:10 -04:00
Guennadi Liakhovetski
8c102a9646 mmc: tmio: add callbacks to enable-update and disable the interface clock
Every time the clock is enabled after possibly being disabled, we have
to re-read its frequency and update our configuration.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Chris Ball <cjb@laptop.org>
2012-07-21 00:02:10 -04:00
Guennadi Liakhovetski
e0337cc8b0 mmc: tmio: don't needlessly enable interrupts during probing
We don't have to force-enable MMC interrupts in our .probe() method,
mmc_add_host() will trigger card detection, that will enable all the
necessary interrupts.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Chris Ball <cjb@laptop.org>
2012-07-21 00:02:09 -04:00
Jonathan Kliegman
3bfe619dc3 mmc: dw_mmc: Fix null dma_ops access when use_dma is false
host->dma_ops is not valid if host->usa dma is 0 so protect
host->dma_ops reference in dw_mci_resume

Signed-off-by: Jonathan Kliegman <kliegs@chromium.org>
Acked-by: Jaehoon Chung <jh80.chung@samsung.com>
Acked-by: Will Newton <will.newton@imgtec.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
2012-07-21 00:02:09 -04:00
Guennadi Liakhovetski
e137788dd1 mmc: add a function to get regulators, supplying card's power
Add a function to get regulators, supplying card's Vdd and Vccq on a
specific host. If a Vdd supplying regulator is found, the function checks,
whether a valid OCR mask can be obtained from it. The Vccq regulator is
optional. A failure to get it is not fatal.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Reviwed-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Chris Ball <cjb@laptop.org>
2012-07-21 00:02:08 -04:00
Laurent Pinchart
6de707f200 mmc: tmio: Don't access hardware registers after stopping clocks
The tmio_mmc_set_ios() function configures the MMC power, clock and bus
width. When the mmc core requests the driver to power off the card, we
inform runtime PM, that the controller can be suspended. This can lead
to the MSTP clock being turned off.

Writing to any 16-bit hardware registers with the MSTP clock off leads
to timeouts and errors being printed to the kernel log. This can occur
both when stopping the MMC clock and when configuring the bus width.

To fix this, stop the MMC clock before calling put_runtime_pm(), and
skip bus width configuration when power is off.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Tested-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Tested-by: Simon Horman <horms@verge.net.au>
Acked-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Chris Ball <cjb@laptop.org>
2012-07-21 00:02:07 -04:00
Laurent Pinchart
7541ca9847 mmc: sh_mmcif: Support MMC_SLEEP_AWAKE command
The MMC_SLEEP_AWAKE and SD_IO_SEND_OP_COND commands share the same
opcode. SD_IO_SEND_OP_COND isn't supported by the SH MMCIF, but
MMC_SLEEP_AWAKE is. Discriminate between the two commands using the
command flags, and reject SD_IO_SEND_OP_COND only.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Chris Ball <cjb@laptop.org>
2012-07-21 00:02:07 -04:00
Girish K S
94c6cee91b mmc: dw_mmc: Add check for IDMAC configuration
In the current dwmmc driver there is support for selecting IDMAC from
the menu config option. If the support for IDMAC is enabled in the menu
config and the hardware configuration register's DMA_INTERFACE field is
0, the driver will still try to do the DMA initialization.

The dw_mci_idmac_init function currently implemented returns only success
indicating that the DMA initialization is always successful. This patch
adds a check for existence of the DMA IP to allow the DMA initialization.

Signed-off-by: Girish K S <girish.shivananjappa@linaro.org>
Acked-by: Will Newton <will.newton@imgtec.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
2012-07-21 00:02:06 -04:00
Chris Ball
b650352dd3 mmc: sdhci-pxa: Add device tree support
Tested on an OLPC XO-1.75.  (MMP2, sdhci-pxav3, CONFIG_MACH_MMP2_DT=y)

Signed-off-by: Chris Ball <cjb@laptop.org>
Acked-by: Haojian Zhuang <haojian.zhuang@gmail.com>
2012-07-21 00:01:47 -04:00
Denis Efremov
186e868786 forcedeth: spin_unlock_irq in interrupt handler fix
The replacement of spin_lock_irq/spin_unlock_irq pair in interrupt
handler by spin_lock_irqsave/spin_lock_irqrestore pair.

Found by Linux Driver Verification project (linuxtesting.org).

Signed-off-by: Denis Efremov <yefremov.denis@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-20 16:18:36 -07:00
David S. Miller
c073cfc89f Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/jesse/openvswitch
Jesse Gross says:

====================
A few bug fixes and small enhancements for net-next/3.6.
 ...
Ansis Atteka (1):
      openvswitch: Do not send notification if ovs_vport_set_options() failed

Ben Pfaff (1):
      openvswitch: Check gso_type for correct sk_buff in queue_gso_packets().

Jesse Gross (2):
      openvswitch: Enable retrieval of TCP flags from IPv6 traffic.
      openvswitch: Reset upper layer protocol info on internal devices.

Leo Alterman (1):
      openvswitch: Fix typo in documentation.

Pravin B Shelar (1):
      openvswitch: Check currect return value from skb_gso_segment()

Raju Subramanian (1):
      openvswitch: Replace Nicira Networks.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-20 16:16:34 -07:00
David S. Miller
0bb4087cbe ipv4: Fix neigh lookup keying over loopback/point-to-point devices.
We were using a special key "0" for all loopback and point-to-point
device neigh lookups under ipv4, but we wouldn't use that special
key for the neigh creation.

So basically we'd make a new neigh at each and every lookup :-)

This special case to use only one neigh for these device types
is of dubious value, so just remove it entirely.

Reported-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-20 16:06:10 -07:00
Arnd Bergmann
233de298cb Merge branch 'lpc32xx/core2' of git://git.antcom.de/linux-2.6 into next/soc
From Roland Stigge <stigge@antcom.de>:
this LPC32xx core update (branch lpc32xx/core2) builds upon the
previously provided lpc32xx/core-fixes. Basically including PWM support
(for the PWM driver from Alexandre already in the pwm tree), and
CPU ID.

* 'lpc32xx/core2' of git://git.antcom.de/linux-2.6:
  ARM: LPC32xx: Add PWM support
  ARM: LPC32xx: Add PWM clock
  ARM: LPC32xx: Set system serial based on cpu unique id

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2012-07-21 00:15:59 +02:00
Arnd Bergmann
1fc5f7d5c6 Merge branch 'lpc32xx/dts2' of git://git.antcom.de/linux-2.6 into next/dt
From Roland Stigge <stigge@antcom.de>:
this is a late addition to LPC32xx DTS files for v3.6.

* 'lpc32xx/dts2' of git://git.antcom.de/linux-2.6:
  ARM: LPC32xx: Add PWM to base dts file

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2012-07-21 00:11:16 +02:00
Leo Alterman
efaac3bf08 openvswitch: Fix typo in documentation.
Signed-off-by: Leo Alterman <lalterman@nicira.com>
Signed-off-by: Jesse Gross <jesse@nicira.com>
2012-07-20 14:51:07 -07:00
Ben Pfaff
a1b5d0dd28 openvswitch: Check gso_type for correct sk_buff in queue_gso_packets().
At the point where it was used, skb_shinfo(skb)->gso_type referred to a
post-GSO sk_buff.  Thus, it would always be 0.  We want to know the pre-GSO
gso_type, so we need to obtain it before segmenting.

Before this change, the kernel would pass inconsistent data to userspace:
packets for UDP fragments with nonzero offset would be passed along with
flow keys that indicate a zero offset (that is, the flow key for "later"
fragments claimed to be "first" fragments).  This inconsistency tended
to confuse Open vSwitch userspace, causing it to log messages about
"failed to flow_del" the flows with "later" fragments.

Signed-off-by: Ben Pfaff <blp@nicira.com>
Signed-off-by: Jesse Gross <jesse@nicira.com>
2012-07-20 14:47:54 -07:00
Pravin B Shelar
92e5dfc34c openvswitch: Check currect return value from skb_gso_segment()
Fix return check typo.

Signed-off-by: Pravin B Shelar <pshelar@nicira.com>
Signed-off-by: Jesse Gross <jesse@nicira.com>
2012-07-20 14:46:29 -07:00
David S. Miller
2860583fe8 ipv4: Kill rt->fi
It's not really needed.

We only grabbed a reference to the fib_info for the sake of fib_info
local metrics.

However, fib_info objects are freed using RCU, as are therefore their
private metrics (if any).

We would have triggered a route cache flush if we eliminated a
reference to a fib_info object in the routing tables.

Therefore, any existing cached routes will first check and see that
they have been invalidated before an errant reference to these
metric values would occur.

Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-20 13:40:07 -07:00
David S. Miller
9917e1e876 ipv4: Turn rt->rt_route_iif into rt->rt_is_input.
That is this value's only use, as a boolean to indicate whether
a route is an input route or not.

So implement it that way, using a u16 gap present in the struct
already.

Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-20 13:40:02 -07:00
David S. Miller
4fd551d7be ipv4: Kill rt->rt_oif
Never actually used.

It was being set on output routes to the original OIF specified in the
flow key used for the lookup.

Adjust the only user, ipmr_rt_fib_lookup(), for greater correctness of
the flowi4_oif and flowi4_iif values, thanks to feedback from Julian
Anastasov.

Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-20 13:38:34 -07:00
David S. Miller
93ac53410a ipv4: Dirty less cache lines in route caching paths.
Don't bother incrementing dst->__use and setting dst->lastuse,
they are completely pointless and just slow things down.

Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-20 13:36:55 -07:00
David S. Miller
ba3f7f04ef ipv4: Kill FLOWI_FLAG_RT_NOCACHE and associated code.
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-20 13:36:54 -07:00
David S. Miller
d2d68ba9fe ipv4: Cache input routes in fib_info nexthops.
Caching input routes is slightly simpler than output routes, since we
don't need to be concerned with nexthop exceptions.  (locally
destined, and routed packets, never trigger PMTU events or redirects
that will be processed by us).

However, we have to elide caching for the DIRECTSRC and non-zero itag
cases.

Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-20 13:36:40 -07:00
David S. Miller
f2bb4bedf3 ipv4: Cache output routes in fib_info nexthops.
If we have an output route that lacks nexthop exceptions, we can cache
it in the FIB info nexthop.

Such routes will have DST_HOST cleared because such routes refer to a
family of destinations, rather than just one.

The sequence of the handling of exceptions during route lookup is
adjusted to make the logic work properly.

Before we allocate the route, we lookup the exception.

Then we know if we will cache this route or not, and therefore whether
DST_HOST should be set on the allocated route.

Then we use DST_HOST to key off whether we should store the resulting
route, during rt_set_nexthop(), in the FIB nexthop cache.

With help from Eric Dumazet.

Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-20 13:36:16 -07:00
David S. Miller
ceb3320610 ipv4: Kill routes during PMTU/redirect updates.
Mark them obsolete so there will be a re-lookup to fetch the
FIB nexthop exception info.

Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-20 13:31:22 -07:00
David S. Miller
f5b0a87436 net: Document dst->obsolete better.
Add a big comment explaining how the field works, and use defines
instead of magic constants for the values assigned to it.

Suggested by Joe Perches.

Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-20 13:31:21 -07:00
David S. Miller
f8126f1d51 ipv4: Adjust semantics of rt->rt_gateway.
In order to allow prefixed routes, we have to adjust how rt_gateway
is set and interpreted.

The new interpretation is:

1) rt_gateway == 0, destination is on-link, nexthop is iph->daddr

2) rt_gateway != 0, destination requires a nexthop gateway

Abstract the fetching of the proper nexthop value using a new
inline helper, rt_nexthop(), as suggested by Joe Perches.

Signed-off-by: David S. Miller <davem@davemloft.net>
Tested-by: Vijay Subramanian <subramanian.vijay@gmail.com>
2012-07-20 13:31:20 -07:00
David S. Miller
f1ce3062c5 ipv4: Remove 'rt_dst' from 'struct rtable'
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-20 13:31:19 -07:00
David Miller
b48698895d ipv4: Remove 'rt_mark' from 'struct rtable'
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-20 13:31:18 -07:00
David Miller
d6c0a4f609 ipv4: Kill 'rt_src' from 'struct rtable'
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-20 13:31:00 -07:00
David Miller
1a00fee4ff ipv4: Remove rt_key_{src,dst,tos} from struct rtable.
They are always used in contexts where they can be reconstituted,
or where the finally resolved rt->rt_{src,dst} is semantically
equivalent.

Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-20 13:30:59 -07:00
David Miller
38a424e465 ipv4: Kill ip_route_input_noref().
The "noref" argument to ip_route_input_common() is now always ignored
because we do not cache routes, and in that case we must always grab
a reference to the resulting 'dst'.

Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-20 13:30:59 -07:00
David S. Miller
89aef8921b ipv4: Delete routing cache.
The ipv4 routing cache is non-deterministic, performance wise, and is
subject to reasonably easy to launch denial of service attacks.

The routing cache works great for well behaved traffic, and the world
was a much friendlier place when the tradeoffs that led to the routing
cache's design were considered.

What it boils down to is that the performance of the routing cache is
a product of the traffic patterns seen by a system rather than being a
product of the contents of the routing tables.  The former of which is
controllable by external entitites.

Even for "well behaved" legitimate traffic, high volume sites can see
hit rates in the routing cache of only ~%10.

Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-20 13:30:27 -07:00
Rafael J. Wysocki
75a4161a58 Merge branch 'pm-cpufreq'
* pm-cpufreq:
  cpufreq: Fix sysfs deadlock with concurrent hotplug/frequency switch
  EXYNOS: bugfix on retrieving old_index from freqs.old
2012-07-20 21:39:50 +02:00
Stephen Boyd
a914443627 cpufreq: Fix sysfs deadlock with concurrent hotplug/frequency switch
Running one program that continuously hotplugs and replugs a cpu
concurrently with another program that continuously writes to the
scaling_setspeed node eventually deadlocks with:

=============================================
[ INFO: possible recursive locking detected ]
3.4.0 #37 Tainted: G        W
---------------------------------------------
filemonkey/122 is trying to acquire lock:
 (s_active#13){++++.+}, at: [<c01a3d28>] sysfs_remove_dir+0x9c/0xb4

but task is already holding lock:
 (s_active#13){++++.+}, at: [<c01a22f0>] sysfs_write_file+0xe8/0x140

other info that might help us debug this:
 Possible unsafe locking scenario:

       CPU0
       ----
  lock(s_active#13);
  lock(s_active#13);

 *** DEADLOCK ***

 May be due to missing lock nesting notation

2 locks held by filemonkey/122:
 #0:  (&buffer->mutex){+.+.+.}, at: [<c01a2230>] sysfs_write_file+0x28/0x140
 #1:  (s_active#13){++++.+}, at: [<c01a22f0>] sysfs_write_file+0xe8/0x140

stack backtrace:
[<c0014fcc>] (unwind_backtrace+0x0/0x120) from [<c00ca600>] (validate_chain+0x6f8/0x1054)
[<c00ca600>] (validate_chain+0x6f8/0x1054) from [<c00cb778>] (__lock_acquire+0x81c/0x8d8)
[<c00cb778>] (__lock_acquire+0x81c/0x8d8) from [<c00cb9c0>] (lock_acquire+0x18c/0x1e8)
[<c00cb9c0>] (lock_acquire+0x18c/0x1e8) from [<c01a3ba8>] (sysfs_addrm_finish+0xd0/0x180)
[<c01a3ba8>] (sysfs_addrm_finish+0xd0/0x180) from [<c01a3d28>] (sysfs_remove_dir+0x9c/0xb4)
[<c01a3d28>] (sysfs_remove_dir+0x9c/0xb4) from [<c02d0e5c>] (kobject_del+0x10/0x38)
[<c02d0e5c>] (kobject_del+0x10/0x38) from [<c02d0f74>] (kobject_release+0xf0/0x194)
[<c02d0f74>] (kobject_release+0xf0/0x194) from [<c0565a98>] (cpufreq_cpu_put+0xc/0x24)
[<c0565a98>] (cpufreq_cpu_put+0xc/0x24) from [<c05683f0>] (store+0x6c/0x74)
[<c05683f0>] (store+0x6c/0x74) from [<c01a2314>] (sysfs_write_file+0x10c/0x140)
[<c01a2314>] (sysfs_write_file+0x10c/0x140) from [<c014af44>] (vfs_write+0xb0/0x128)
[<c014af44>] (vfs_write+0xb0/0x128) from [<c014b06c>] (sys_write+0x3c/0x68)
[<c014b06c>] (sys_write+0x3c/0x68) from [<c000e0e0>] (ret_fast_syscall+0x0/0x3c)

This is because store() in cpufreq.c indirectly calls
kobject_get() via cpufreq_cpu_get() and is the last one to call
kobject_put() via cpufreq_cpu_put(). Sysfs code should not call
kobject_get() or kobject_put() directly (see the comment around
sysfs_schedule_callback() for more information).

Fix this deadlock by introducing two new functions:

	struct cpufreq_policy *cpufreq_cpu_get_sysfs(unsigned int cpu)
	void cpufreq_cpu_put_sysfs(struct cpufreq_policy *data)

which do the same thing as cpufreq_cpu_{get,put}() but don't call
kobject functions.

To easily trigger this deadlock you can insert an msleep() with a
reasonably large value right after the fail label at the bottom
of the store() function in cpufreq.c and then write
scaling_setspeed in one task and offline the cpu in another. The
first task will hang and be detected by the hung task detector.

Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2012-07-20 21:39:25 +02:00
Linus Torvalds
d75e2c9ad9 Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus
Pull late MIPS fixes from Ralf Baechle:
 "This fixes a number of lose ends in the MIPS code and various bug
  fixes.

  Aside of dropping some patch that should not be in this pull request
  everything has sat in -next for quite a while and there are no known
  issues.

  The biggest patch in this patch set moves the allocation of an array
  that is aliased to a function (for runtime generated code) to
  assembler code.  This avoids an issue with certain toolchains when
  building for microMIPS."

* 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus: (35 commits)
  MIPS: PCI: Move fixups from __init to __devinit.
  MIPS: Fix bug.h MIPS build regression
  MIPS: sync-r4k: remove redundant irq operation
  MIPS: smp: Warn on too early irq enable
  MIPS: call set_cpu_online() on cpu being brought up with irq disabled
  MIPS: call ->smp_finish() a little late
  MIPS: Yosemite: delay irq enable to ->smp_finish()
  MIPS: SMTC: delay irq enable to ->smp_finish()
  MIPS: BMIPS: delay irq enable to ->smp_finish()
  MIPS: Octeon: delay enable irq to ->smp_finish()
  MIPS: Oprofile: Fix build as a module.
  MIPS: BCM63XX: Fix BCM6368 IPSec clock bit
  MIPS: perf: Fix build error caused by unused counters_per_cpu_to_total()
  MIPS: Fix Magic SysRq L kernel crash.
  MIPS: BMIPS: Fix duplicate header inclusion.
  mips: mark const init data with __initconst instead of __initdata
  MIPS: cmpxchg.h: Add missing include
  MIPS: Malta may also be equipped with MIPS64 R2 processors.
  MIPS: Fix typo multipy -> multiply
  MIPS: Cavium: Fix duplicate ARCH_SPARSEMEM_ENABLE in kconfig.
  ...
2012-07-20 12:02:02 -07:00