lkml.org 
[lkml]   [2021]   [Oct]   [30]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH 03/13] power: supply: bq25890: Fix race causing oops at boot
    Date
    Before this commit the driver was registering its interrupt handler before
    it registered the power_supply, causing bq->charger to potentially be NULL
    when the interrupt handler runs, triggering a NULL pointer exception in
    the interrupt handler:

    [ 21.213531] BUG: kernel NULL pointer dereference, address: 0000000000000680
    ...
    [ 21.213573] Hardware name: Xiaomi Inc Mipad2/Mipad, BIOS MIPad-P4.X64.0043.R03.1603071414 03/07/2016
    [ 21.213576] RIP: 0010:__lock_acquire+0x5c5/0x1de0
    ...
    [ 21.213629] Call Trace:
    [ 21.213636] ? disable_irq_nosync+0x10/0x10
    [ 21.213644] ? __mutex_unlock_slowpath+0x35/0x260
    [ 21.213655] lock_acquire+0xb5/0x2b0
    [ 21.213661] ? power_supply_changed+0x23/0x90
    [ 21.213670] ? disable_irq_nosync+0x10/0x10
    [ 21.213676] _raw_spin_lock_irqsave+0x48/0x60
    [ 21.213682] ? power_supply_changed+0x23/0x90
    [ 21.213687] power_supply_changed+0x23/0x90
    [ 21.213697] __bq25890_handle_irq+0x5e/0xe0 [bq25890_charger]
    [ 21.213709] bq25890_irq_handler_thread+0x26/0x40 [bq25890_charger]
    [ 21.213718] irq_thread_fn+0x20/0x60
    ...

    Fix this by moving the power_supply_register() call to above the
    request_threaded_irq() call.

    Note this fix includes making the following 2 (necessary) changes:

    1. Switch to the devm version of power_supply_register() to avoid the
    need to make the error-handling in probe() more complicated.

    2. Rename the "irq_fail" label to "err_unregister_usb_notifier" since
    the old name no longer makes sense after this fix.

    Signed-off-by: Hans de Goede <hdegoede@redhat.com>
    ---
    drivers/power/supply/bq25890_charger.c | 23 +++++++++++------------
    1 file changed, 11 insertions(+), 12 deletions(-)

    diff --git a/drivers/power/supply/bq25890_charger.c b/drivers/power/supply/bq25890_charger.c
    index 945c3257ca93..491d36a3811a 100644
    --- a/drivers/power/supply/bq25890_charger.c
    +++ b/drivers/power/supply/bq25890_charger.c
    @@ -734,8 +734,9 @@ static int bq25890_power_supply_init(struct bq25890_device *bq)
    psy_cfg.supplied_to = bq25890_charger_supplied_to;
    psy_cfg.num_supplicants = ARRAY_SIZE(bq25890_charger_supplied_to);

    - bq->charger = power_supply_register(bq->dev, &bq25890_power_supply_desc,
    - &psy_cfg);
    + bq->charger = devm_power_supply_register(bq->dev,
    + &bq25890_power_supply_desc,
    + &psy_cfg);

    return PTR_ERR_OR_ZERO(bq->charger);
    }
    @@ -985,22 +986,22 @@ static int bq25890_probe(struct i2c_client *client,
    usb_register_notifier(bq->usb_phy, &bq->usb_nb);
    }

    + ret = bq25890_power_supply_init(bq);
    + if (ret < 0) {
    + dev_err(dev, "Failed to register power supply\n");
    + goto err_unregister_usb_notifier;
    + }
    +
    ret = devm_request_threaded_irq(dev, client->irq, NULL,
    bq25890_irq_handler_thread,
    IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
    BQ25890_IRQ_PIN, bq);
    if (ret)
    - goto irq_fail;
    -
    - ret = bq25890_power_supply_init(bq);
    - if (ret < 0) {
    - dev_err(dev, "Failed to register power supply\n");
    - goto irq_fail;
    - }
    + goto err_unregister_usb_notifier;

    return 0;

    -irq_fail:
    +err_unregister_usb_notifier:
    if (!IS_ERR_OR_NULL(bq->usb_phy))
    usb_unregister_notifier(bq->usb_phy, &bq->usb_nb);

    @@ -1011,8 +1012,6 @@ static int bq25890_remove(struct i2c_client *client)
    {
    struct bq25890_device *bq = i2c_get_clientdata(client);

    - power_supply_unregister(bq->charger);
    -
    if (!IS_ERR_OR_NULL(bq->usb_phy))
    usb_unregister_notifier(bq->usb_phy, &bq->usb_nb);

    --
    2.31.1
    \
     
     \ /
      Last update: 2021-10-30 20:28    [W:3.956 / U:0.000 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site