Re: [patch] IBM HDAPS accelerometer driver, with probing.

[Dmitry Torokhov <dmitry.torokhov@gmail.com>]

On 8/26/05, Robert Love <rml@novell.com> wrote:

> +static void hdaps_calibrate(void)
> +{
> +       int x, y, ret;
> +
> +       ret = accelerometer_read_pair(HDAPS_PORT_XPOS, HDAPS_PORT_YPOS, &x, &y);
> +       if (unlikely(ret))
> +               return;
> +
> +       rest_x = x;
> +       rest_y = y;
> +}

Is this function used in a hot path to warrant using "unlikely"? There
are to many "unlikely" in the code for my taste.

> +
> +static ssize_t hdaps_mousedev_store(struct device *dev,
> +                                   struct device_attribute *attr,
> +                                   const char *buf, size_t count)
> +{
> +       int enable;
> +
> +       if (sscanf(buf, "%d", &enable) != 1)
> +               return -EINVAL;
> +
> +       spin_lock(&hdaps_lock);
> +       if (enable == 1)
> +               hdaps_mousedev_enable();
> +       else if (enable == 0)
> +               hdaps_mousedev_disable();
> +       spin_unlock(&hdaps_lock);
> +
> +       return count;
> +}

input_[un]register_device and del_timer_sync are "long" operations. I
think a semaphore would be better here.

-- 
Dmitry