Re: [PATCH] input: joystick: Adding Austria Microsystem AS5011joystick driver (second version)

From: Dmitry Torokhov
Date: Sun Jan 02 2011 - 03:46:42 EST


Hi Fabien,

On Fri, Dec 31, 2010 at 12:38:07PM +0100, Fabien Marteau wrote:
> Hi Trilok,
>
> >
> >> + int ret;
> >> +
> >> + mutex_lock(&plat_dat->button_lock);
> >> + ret = gpio_get_value(plat_dat->button_gpio);
> >> + if (ret)
> >> + input_report_key(plat_dat->input_dev, BTN_JOYSTICK, 0);
> >> + else
> >> + input_report_key(plat_dat->input_dev, BTN_JOYSTICK, 1);
> >> + input_sync(plat_dat->input_dev);
> >> + mutex_unlock(&plat_dat->button_lock);
> >
> > Do you need this lock? Please explain.
>
> If gpio_get_value() sleep, I need it to avoid race condition.

Race condition with what though?

>
> >> +static int as5011_i2c_write(struct i2c_client *client,
> >> + uint8_t aRegAddr,
> >> + uint8_t aValue)
> >> +{
> >> + int ret;
> >> + uint8_t data[2] = { aRegAddr, aValue };
> >
> > No CamelCases please. Please run scripts/checkpatch.pl on your patch before submission.
>
> I had no warning for CamelCases name.

This goes wihtout saying ;)

>
> >> +static int __devinit as5011_probe(struct i2c_client *client,
> >> + const struct i2c_device_id *id)
> >> +{
> >> + struct as5011_platform_data *plat_dat = client->dev.platform_data;
> >> + int retval = 0;
> >> +
> >> + plat_dat->num = g_num;
> >> + g_num++;
> >
> > What is g_num++ and why it has to be global?
>
> It's for interruptions name, if several as5011 joystick I set a number different for each joystick :
>
> scnprintf(plat_dat->button_irq_name,
> SIZE_NAME,
> "as5011_%d_button",
> plat_dat->num);

Right, but who cares about having different names? Just mark all
interrupts as5011_button and as5011_joystick or even simply use "as5011"
for everything and call it a day.

--
Dmitry
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