From 32ecc75ded72e0425713a7ffe2050fef6e54e564 Mon Sep 17 00:00:00 2001 From: Andrey Rusalin Date: Wed, 28 Dec 2016 20:10:59 +0300 Subject: NFC: pn533: change order operations in dev registation Sometimes during probing and registration of pn533_i2c NULL pointer dereference happens. Reproduced in cycle of inserting and removing pn533_i2c and pn533 modules. Backtrace: [<8004205c>] (__queue_work) from [<80042324>] (queue_work_on+0x50/0x5c) r10:acdc7c80 r9:8006b330 r8:ac0dfb40 r7:ac50c600 r6:00000004 r5:acbbee40 r4:600f0113 [<800422d4>] (queue_work_on) from [<7f7d5b6c>] (pn533_recv_frame+0x158/0x1fc [pn533]) r7:ffffff87 r6:00000000 r5:acbbee40 r4:acbbee00 [<7f7d5a14>] (pn533_recv_frame [pn533]) from [<7f7df4b8>] (pn533_i2c_irq_thread_fn+0x184/0x) r6:acb2a000 r5:00000000 r4:acdc7b90 [<7f7df334>] (pn533_i2c_irq_thread_fn [pn533_i2c]) from [<8006b354>] (irq_thread_fn+0x24/0x) r7:00000000 r6:accde000 r5:ac0dfb40 r4:acdc7c80 ... Seems there is some race condition due registration of irq handler until all data stuctures that could be needed are ready. So I re-ordered some ops. After this, problem has gone. Changes in USB part was not tested, but it should not break anything. Signed-off-by: Andrey Rusalin Signed-off-by: Samuel Ortiz --- drivers/nfc/pn533/i2c.c | 28 ++++++++++++++++++---------- 1 file changed, 18 insertions(+), 10 deletions(-) (limited to 'drivers/nfc/pn533/i2c.c') diff --git a/drivers/nfc/pn533/i2c.c b/drivers/nfc/pn533/i2c.c index 11d78b43cf76..2c2fb9cfe10a 100644 --- a/drivers/nfc/pn533/i2c.c +++ b/drivers/nfc/pn533/i2c.c @@ -206,14 +206,6 @@ static int pn533_i2c_probe(struct i2c_client *client, phy->i2c_dev = client; i2c_set_clientdata(client, phy); - r = request_threaded_irq(client->irq, NULL, pn533_i2c_irq_thread_fn, - IRQF_TRIGGER_FALLING | - IRQF_SHARED | IRQF_ONESHOT, - PN533_I2C_DRIVER_NAME, phy); - - if (r < 0) - nfc_err(&client->dev, "Unable to register IRQ handler\n"); - priv = pn533_register_device(PN533_DEVICE_PN532, PN533_NO_TYPE_B_PROTOCOLS, PN533_PROTO_REQ_ACK_RESP, @@ -223,16 +215,32 @@ static int pn533_i2c_probe(struct i2c_client *client, if (IS_ERR(priv)) { r = PTR_ERR(priv); - goto err_register; + return r; } phy->priv = priv; + r = request_threaded_irq(client->irq, NULL, pn533_i2c_irq_thread_fn, + IRQF_TRIGGER_FALLING | + IRQF_SHARED | IRQF_ONESHOT, + PN533_I2C_DRIVER_NAME, phy); + if (r < 0) { + nfc_err(&client->dev, "Unable to register IRQ handler\n"); + goto irq_rqst_err; + } + + r = pn533_finalize_setup(priv); + if (r) + goto fn_setup_err; + return 0; -err_register: +fn_setup_err: free_irq(client->irq, phy); +irq_rqst_err: + pn533_unregister_device(phy->priv); + return r; } -- cgit v1.2.3