Re: [PATCH] Add Cobalt button interface driver support

On Thursday 15 February 2007 22:36, Yoichi Yuasa wrote:

Hi,

This patch adds support for the back panel buttons on Cobalt server.
It's tested on the Cobalt Qube2.

Hi,

Thank you for your patch. Couple of comments:

+
+		button++;
+	}
+
+	mod_timer(&buttons_timer, jiffies + HZ / BUTTONS_POLL_FREQUENCY);

May I suggest using msecs_to_jiffies() to avoid direct computations on HZ?

+
+	bdev->input = input;
+	bdev->reg = ioremap(res->start, res->end - res->start + 1);
+	dev_set_drvdata(&pdev->dev, bdev);
+
+	setup_timer(&buttons_timer, handle_buttons, (unsigned long)bdev);
+	mod_timer(&buttons_timer, jiffies + HZ / BUTTONS_POLL_FREQUENCY);

Please implement cobalt_buttons_open() and cobalt_buttons_close() methods
and start/stop timer from there - there is no point in polling hardware
if noone is listening to the events.

+
+	return retval;
+}
+
+static int __devexit cobalt_buttons_remove(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct buttons_dev *bdev = dev_get_drvdata(dev);
+
+	del_timer(&buttons_timer);

del_timer_sync? Is there any possibility it may run SMP?

+
+static void __exit cobalt_buttons_exit(void)
+{
+	platform_driver_unregister(&cobalt_buttons_driver);

You are not allowed to unregister statically allocated devices -
if there are references left and your module goes away then
these references become invalid and kernel goes boom.

Please convert to platform_device_alloc/platform_device_add.

Is there a point of moving platform device creation code into
platform-specific code? Is there a possibility of this driver
being used elsewhere?

+	platform_device_unregister(&cobalt_buttons_device);
+}
+
+module_init(cobalt_buttons_init);
+module_exit(cobalt_buttons_exit);

-- 
Dmitry