linux-toradex.git/drivers/power/pda_power.c, branch v4.4.3

power_supply: Change ownership from driver to core

2015-03-13T22:15:51+00:00

Change the ownership of power_supply structure from each driver
implementing the class to the power supply core.

The patch changes power_supply_register() function thus all drivers
implementing power supply class are adjusted.

Each driver provides the implementation of power supply. However it
should not be the owner of power supply class instance because it is
exposed by core to other subsystems with power_supply_get_by_name().
These other subsystems have no knowledge when the driver will unregister
the power supply. This leads to several issues when driver is unbound -
mostly because user of power supply accesses freed memory.

Instead let the core own the instance of struct 'power_supply'.  Other
users of this power supply will still access valid memory because it
will be freed when device reference count reaches 0. Currently this
means "it will leak" but power_supply_put() call in next patches will
solve it.

This solves invalid memory references in following race condition
scenario:

Thread 1: charger manager
Thread 2: power supply driver, used by charger manager

THREAD 1 (charger manager)         THREAD 2 (power supply driver)
==========================         ==============================
psy = power_supply_get_by_name()
                                   Driver unbind, .remove
                                     power_supply_unregister()
                                     Device fully removed
psy->get_property()

The 'get_property' call is executed in invalid context because the driver was
unbound and struct 'power_supply' memory was freed.

This could be observed easily with charger manager driver (here compiled
with max17040 fuel gauge):

$ cat /sys/devices/virtual/power_supply/cm-battery/capacity &
$ echo "1-0036" > /sys/bus/i2c/drivers/max17040/unbind
[   55.725123] Unable to handle kernel NULL pointer dereference at virtual address 00000000
[   55.732584] pgd = d98d4000
[   55.734060] [00000000] *pgd=5afa2831, *pte=00000000, *ppte=00000000
[   55.740318] Internal error: Oops: 80000007 [#1] PREEMPT SMP ARM
[   55.746210] Modules linked in:
[   55.749259] CPU: 1 PID: 2936 Comm: cat Tainted: G        W       3.19.0-rc1-next-20141226-00048-gf79f475f3c44-dirty #1496
[   55.760190] Hardware name: SAMSUNG EXYNOS (Flattened Device Tree)
[   55.766270] task: d9b76f00 ti: daf54000 task.ti: daf54000
[   55.771647] PC is at 0x0
[   55.774182] LR is at charger_get_property+0x2f4/0x36c
[   55.779201] pc : [<00000000>]    lr : []    psr: 60000013
[   55.779201] sp : daf55e90  ip : 00000003  fp : 00000000
[   55.790657] r10: 00000000  r9 : c06e2878  r8 : d9b26c68
[   55.795865] r7 : dad81610  r6 : daec7410  r5 : daf55ebc  r4 : 00000000
[   55.802367] r3 : 00000000  r2 : daf55ebc  r1 : 0000002a  r0 : d9b26c68
[   55.808879] Flags: nZCv  IRQs on  FIQs on  Mode SVC_32  ISA ARM  Segment user
[   55.815994] Control: 10c5387d  Table: 598d406a  DAC: 00000015
[   55.821723] Process cat (pid: 2936, stack limit = 0xdaf54210)
[   55.827451] Stack: (0xdaf55e90 to 0xdaf56000)
[   55.831795] 5e80:                                     60000013 c01459c4 0000002a c06f8ef8
[   55.839956] 5ea0: db651000 c06f8ef8 daebac00 c04cb668 daebac08 c0346864 00000000 c01459c4
[   55.848115] 5ec0: d99eaa80 c06f8ef8 00000fff 00001000 db651000 c027f25c c027f240 d99eaa80
[   55.856274] 5ee0: d9a06c00 c0146218 daf55f18 00001000 d99eaa80 db4c18c0 00000001 00000001
[   55.864468] 5f00: daf55f80 c0144c78 c0144c54 c0107f90 00015000 d99eaab0 00000000 00000000
[   55.872603] 5f20: 000051c7 00000000 db4c18c0 c04a9370 00015000 00001000 daf55f80 00001000
[   55.880763] 5f40: daf54000 00015000 00000000 c00e53dc db4c18c0 c00e548c 0000000d 00008124
[   55.888937] 5f60: 00000001 00000000 00000000 db4c18c0 db4c18c0 00001000 00015000 c00e5550
[   55.897099] 5f80: 00000000 00000000 00001000 00001000 00015000 00000003 00000003 c000f364
[   55.905239] 5fa0: 00000000 c000f1a0 00001000 00015000 00000003 00015000 00001000 0001333c
[   55.913399] 5fc0: 00001000 00015000 00000003 00000003 00000002 00000000 00000000 00000000
[   55.921560] 5fe0: 7fffe000 be999850 0000a225 b6f3c19c 60000010 00000003 00000000 00000000
[   55.929744] [] (charger_get_property) from [] (power_supply_show_property+0x48/0x20c)
[   55.939286] [] (power_supply_show_property) from [] (dev_attr_show+0x1c/0x48)
[   55.948130] [] (dev_attr_show) from [] (sysfs_kf_seq_show+0x84/0x104)
[   55.956298] [] (sysfs_kf_seq_show) from [] (kernfs_seq_show+0x24/0x28)
[   55.964536] [] (kernfs_seq_show) from [] (seq_read+0x1b0/0x484)
[   55.972172] [] (seq_read) from [] (__vfs_read+0x18/0x4c)
[   55.979188] [] (__vfs_read) from [] (vfs_read+0x7c/0x100)
[   55.986304] [] (vfs_read) from [] (SyS_read+0x40/0x8c)
[   55.993164] [] (SyS_read) from [] (ret_fast_syscall+0x0/0x48)
[   56.000626] Code: bad PC value
[   56.011652] ---[ end trace 7b64343fbdae8ef1 ]---

Signed-off-by: Krzysztof Kozlowski 
Reviewed-by: Bartlomiej Zolnierkiewicz 

[for the nvec part]
Reviewed-by: Marc Dietrich 

[for compal-laptop.c]
Acked-by: Darren Hart 

[for the mfd part]
Acked-by: Lee Jones 

[for the hid part]
Acked-by: Jiri Kosina 

[for the acpi part]
Acked-by: Rafael J. Wysocki 

Signed-off-by: Sebastian Reichel

power_supply: Move run-time configuration to separate structure

2015-03-13T22:15:12+00:00

Add new structure 'power_supply_config' for holding run-time
initialization data like of_node, supplies and private driver data.

The power_supply_register() function is changed so all power supply
drivers need updating.

When registering the power supply this new 'power_supply_config' should be
used instead of directly initializing 'struct power_supply'. This allows
changing the ownership of power_supply structure from driver to the
power supply core in next patches.

When a driver does not use of_node or supplies then it should use NULL
as config. If driver uses of_node or supplies then it should allocate
config on stack and initialize it with proper values.

Signed-off-by: Krzysztof Kozlowski 
Reviewed-by: Bartlomiej Zolnierkiewicz 
Acked-by: Pavel Machek 

[for the nvec part]
Reviewed-by: Marc Dietrich 

[for drivers/platform/x86/compal-laptop.c]
Reviewed-by: Darren Hart 

[for drivers/hid/*]
Reviewed-by: Jiri Kosina 

Signed-off-by: Sebastian Reichel

usb: power: pda_power: check against CONFIG_USB_PHY

2013-03-18T09:18:05+00:00

CONFIG_USB_OTG_UTILS will be removed very
soon, so we should check CONFIG_USB_PHY
instead.

Signed-off-by: Felipe Balbi

pda_power: Remove ac_draw_failed goto and label

2012-09-21T23:50:11+00:00

A previous patch added the ac_draw_failed goto and label to
pda_power_probe(). The goto would be invoked after a failed call to
regulator_get().

However the way ac_draw is used - always after a check for NULL - suggests
that a failed call to regulator_get() was not fatal.

This patch removes the ac_draw_failed goto and label, partly reverting the
previous patch.

This patch also removes the assignment of an error code to ret after a
failed call to regulator_get(), since the error code is now never used.

Signed-off-by: Paul Parsons 
Cc: Philipp Zabel 
Signed-off-by: Anton Vorontsov

pda_power: Fix ac_draw usage before it being set

2012-09-20T21:27:34+00:00

When I reboot my iPAQ hx4700 in its cradle, the battery will not begin
to charge even though the AC supply is connected. Charging will start
only after the PDA power driver is tickled by some other power event,
such as reseating the iPAQ in its cradle or connecting the USB cable.

The problem lies in pda_power_probe(), where ac_draw is used by the call
to update_charger() before being set by the call to regulator_get().

Moving the regulator_get() call to before the update_charger() call
fixes the problem.

Signed-off-by: Paul Parsons 
Cc: Philipp Zabel 
Signed-off-by: Anton Vorontsov

Merge tag 'random_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/random

2012-08-01T02:07:42+00:00

Pull random subsystem patches from Ted Ts'o:
 "This patch series contains a major revamp of how we collect entropy
  from interrupts for /dev/random and /dev/urandom.

  The goal is to addresses weaknesses discussed in the paper "Mining
  your Ps and Qs: Detection of Widespread Weak Keys in Network Devices",
  by Nadia Heninger, Zakir Durumeric, Eric Wustrow, J.  Alex Halderman,
  which will be published in the Proceedings of the 21st Usenix Security
  Symposium, August 2012.  (See https://factorable.net for more
  information and an extended version of the paper.)"

Fix up trivial conflicts due to nearby changes in
drivers/{mfd/ab3100-core.c, usb/gadget/omap_udc.c}

* tag 'random_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/random: (33 commits)
  random: mix in architectural randomness in extract_buf()
  dmi: Feed DMI table to /dev/random driver
  random: Add comment to random_initialize()
  random: final removal of IRQF_SAMPLE_RANDOM
  um: remove IRQF_SAMPLE_RANDOM which is now a no-op
  sparc/ldc: remove IRQF_SAMPLE_RANDOM which is now a no-op
  [ARM] pxa: remove IRQF_SAMPLE_RANDOM which is now a no-op
  board-palmz71: remove IRQF_SAMPLE_RANDOM which is now a no-op
  isp1301_omap: remove IRQF_SAMPLE_RANDOM which is now a no-op
  pxa25x_udc: remove IRQF_SAMPLE_RANDOM which is now a no-op
  omap_udc: remove IRQF_SAMPLE_RANDOM which is now a no-op
  goku_udc: remove IRQF_SAMPLE_RANDOM which was commented out
  uartlite: remove IRQF_SAMPLE_RANDOM which is now a no-op
  drivers: hv: remove IRQF_SAMPLE_RANDOM which is now a no-op
  xen-blkfront: remove IRQF_SAMPLE_RANDOM which is now a no-op
  n2_crypto: remove IRQF_SAMPLE_RANDOM which is now a no-op
  pda_power: remove IRQF_SAMPLE_RANDOM which is now a no-op
  i2c-pmcmsp: remove IRQF_SAMPLE_RANDOM which is now a no-op
  input/serio/hp_sdc.c: remove IRQF_SAMPLE_RANDOM which is now a no-op
  mfd: remove IRQF_SAMPLE_RANDOM which is now a no-op
  ...

Merge tag 'for-v3.6' of git://git.infradead.org/battery-2.6

2012-08-01T01:08:25+00:00

Pull battery updates from Anton Vorontsov:
 "The tag contains just a few battery-related changes for v3.6.  It's is
  all pretty straightforward, except one thing.

  One of our patches added thermal support for power supply class, but
  thermal/ subsystem changed under our feet.  We (well, Stephen, that
  is) caught the issue and it was decided[1] that I'd just delay the
  battery pull request, and then will fix it up by merging upstream back
  into battery tree at the specific commit.

  That's not all though: another[2] small fixup for thermal subsystem
  was needed to get rid of a warning in power supply subsystem (the
  warning was not drivers/power's "fault", the thermal registration
  function just needed a proper const annotation, which is also done by
  a small commit on top of the merge.

  So, to sum this up:
   - The 'master' branch of the battery tree was in the -next tree for
     weeks, was never rebased, altered etc.  It should be all OK;
   - Although, for-v3.6 tag contains the 'master' branch + merge + the
     warning fix.

  [1] http://lkml.org/lkml/2012/6/19/23
  [2] http://lkml.org/lkml/2012/6/18/28"

* tag 'for-v3.6' of git://git.infradead.org/battery-2.6: (23 commits)
  thermal: Constify 'type' argument for the registration routine
  olpc-battery: update CHARGE_FULL_DESIGN property for BYD LiFe batteries
  olpc-battery: Add VOLTAGE_MAX_DESIGN property
  charger-manager: Fix build break related to EXTCON
  lp8727_charger: Move header file into platform_data directory
  power_supply: Add min/max alert properties for CAPACITY, TEMP, TEMP_AMBIENT
  bq27x00_battery: Add support for BQ27425 chip
  charger-manager: Set current limit of regulator for over current protection
  charger-manager: Use EXTCON Subsystem to detect charger cables for charging
  test_power: Add VOLTAGE_NOW and BATTERY_TEMP properties
  test_power: Add support for USB AC source
  gpio-charger: Use cansleep version of gpio_set_value
  bq27x00_battery: Add support for power average and health properties
  sbs-battery: Don't trigger false supply_changed event
  twl4030_charger: Allow charger to control the regulator that feeds it
  twl4030_charger: Add backup-battery charging
  twl4030_charger: Fix some typos
  max17042_battery: Support CHARGE_COUNTER power supply attribute
  smb347-charger: Add constant charge and current properties
  power_supply: Add constant charge_current and charge_voltage properties
  ...

pda_power: remove IRQF_SAMPLE_RANDOM which is now a no-op

2012-07-19T14:38:48+00:00

With the changes in the random tree, IRQF_SAMPLE_RANDOM is now a
no-op; interrupt randomness is now collected unconditionally in a very
low-overhead fashion; see commit 775f4b297b.  The IRQF_SAMPLE_RANDOM
flag was scheduled to be removed in 2009 on the
feature-removal-schedule, so this patch is preparation for the final
removal of this flag.

Signed-off-by: "Theodore Ts'o" 
Acked-by: Anton Vorontsov 
Cc: David Woodhouse

usb: phy: fix return value check of usb_get_phy

2012-07-02T07:40:49+00:00

usb_get_phy will return -ENODEV if it's not able to find the phy. Hence
fixed all the callers of usb_get_phy to check for this error condition
instead of relying on a non-zero value as success condition.

Signed-off-by: Kishon Vijay Abraham I 
Signed-off-by: Felipe Balbi

usb: otg: support for multiple transceivers by a single controller

2012-06-25T11:05:35+00:00

Add a linked list for keeping multiple PHY instances with different
types so that we can have separate USB2 and USB3 PHYs on one single
board. _get_phy_ has been changed so that the controller gets
the transceiver by type. _remove_phy_ has been added to let the phy
be removed from the phy list.

Signed-off-by: Kishon Vijay Abraham I 
Signed-off-by: Felipe Balbi