Re: [PATCH 1/2] input: misc: add twl4030-pwrbutton driver

Dmitry Torokhov
2009-02-28T22:23:27Z

Hi Felipe,

On Fri, Feb 27, 2009 at 09:28:02PM +0200, Felipe Balbi wrote:
> From: Felipe Balbi <felipe.balbi@nokia.com>
>
> This is part of the twl4030 multifunction device driver.
>
> With this driver we add support for reporting KEY_POWER
> events via the input layer.

...

>
> +
> + err = twl4030_i2c_read_u8(TWL4030_MODULE_PM_MASTER, &value,
> + STS_HW_CONDITIONS);
> + if (!err) {
> + input_report_key(powerbutton_dev, KEY_POWER,
> + value & PWR_PWRON_IRQ);

input_sync() here please.

> + } else {
> + dev_err(dbg_dev, "twl4030: i2c error %d while reading TWL4030"
> + " PM_MASTER STS_HW_CONDITIONS register\n", err);
> + }
> +
> + return IRQ_HANDLED;
> +}
> +
> +static int __devinit twl4030_pwrbutton_probe(struct platform_device *pdev)
> +{
> + int err = 0;
> + int irq = platform_get_irq(pdev, 0);
> +
> + dbg_dev = &pdev->dev;
> +
> + /* PWRBTN == PWRON */
> + err = request_irq(irq, powerbutton_irq,
> + IRQF_TRIGGER_FALLING | IRQF_TRIGGER_RISING,
> + "twl4030-pwrbutton", NULL);

Requesting IRQ before allocating input device seems unsafe. If IRQ
arrives right now we'll go boom.

> + if (err < 0) {
> + dev_dbg(&pdev->dev, "Can't get IRQ for pwrbutton: %d\n", err);
> + goto out;
> + }
> +
> + powerbutton_dev = input_allocate_device();
> + if (!powerbutton_dev) {
> + dev_dbg(&pdev->dev, "Can't allocate power button\n");
> + err = -ENOMEM;
> + goto free_irq_and_out;
> + }
> +
> + powerbutton_dev->evbit[0] = BIT_MASK(EV_KEY);
> + powerbutton_dev->keybit[BIT_WORD(KEY_POWER)] = BIT_MASK(KEY_POWER);
> + powerbutton_dev->name = "triton2-pwrbutton";

powerbutton_dev->dev.parent = &pdev->dev;

Any chance we could set up phys as well? BUS_I2C seems to be in order as
well.

> +
> + err = input_register_device(powerbutton_dev);
> + if (err) {
> + dev_dbg(&pdev->dev, "Can't register power button: %d\n", err);
> + goto free_input_dev;
> + }
> +
> + dev_info(&pdev->dev, "triton2 power button driver initialized\n");
> +
> + return 0;
> +
> +
> +free_input_dev:
> + input_free_device(powerbutton_dev);
> +free_irq_and_out:
> + free_irq(TWL4030_PWRIRQ_PWRBTN, NULL);
> +out:
> + return err;
> +}
> +
> +static int __devexit twl4030_pwrbutton_remove(struct platform_device *pdev)
> +{
> + int irq = platform_get_irq(pdev, 0);
> +
> + free_irq(irq, NULL);
> + input_unregister_device(powerbutton_dev);
> + input_free_device(powerbutton_dev);

Do not call free after unregistering, unregister will drop last
reference and will cause device structure be freed.

--
Dmitry