14 Mar, 2015

1 commit

  • 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 : [] 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

    Krzysztof Kozlowski
     

07 Mar, 2013

2 commits


23 Jan, 2013

5 commits

  • The AC charger plug-in detection while booting causes I2C read
    failure if AC charger is not connected. Now the LPN pin is enabled
    for every PM2301 register access, which solves the issue.

    Signed-off-by: Rupesh Kumar
    Signed-off-by: Lee Jones
    Reviewed-by: Marcus COOPER
    Reviewed-by: Vijaya Kumar K-1
    Reviewed-by: Rabin VINCENT
    Reviewed-by: Jonas ABERG
    Tested-by: Jonas ABERG

    Lee Jones
     
  • AB and PMxxx doesn't have same watchdog refresh period. Add watchdog
    to refresh period parameters in x500 charger structure, this should
    kick watchdog every 30sec. The AC charging should also kick both
    pm2xxx and the AB charger watchdog.

    Signed-off-by: Rajkumar Kasirajan
    Signed-off-by: Loic Pallardy
    Signed-off-by: Lee Jones
    Reviewed-by: Michel JAOUEN
    Reviewed-by: Marcus COOPER
    Reviewed-by: Jonas ABERG
    Tested-by: Michel JAOUEN
    Tested-by: Jonas ABERG

    Loic Pallardy
     
  • There is no support to measure the main charger voltage and
    current using AB9540 gpadc. Therefore this has been removed
    from the driver.

    Signed-off-by: Rajkumar Kasirajan
    Signed-off-by: Lee Jones
    Reviewed-by: Michel JAOUEN
    Reviewed-by: Rabin VINCENT
    Tested-by: Michel JAOUEN

    Loic Pallardy
     
  • Fix the way interrupts are handled within the PM2301 charging driver.

    Signed-off-by: Rajkumar Kasirajan
    Signed-off-by: Lee Jones
    Reviewed-by: Olivier CLERGEAUD
    Reviewed-by: Marcus COOPER
    Reviewed-by: Michel JAOUEN
    Tested-by: Michel JAOUEN

    Olivier Clergeaud
     
  • Also shift the file description to a more suitable location.

    Signed-off-by: Lee Jones

    Lee Jones