[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <d120d5000710150848t1993b0aavbbc0cd7971e3ef3e@mail.gmail.com>
Date: Mon, 15 Oct 2007 11:48:17 -0400
From: "Dmitry Torokhov" <dmitry.torokhov@...il.com>
To: bryan.wu@...log.com
Cc: "Andrey Panin" <pazke@...pac.ru>, "Roel Kluin" <12o3l@...cali.nl>,
"Ahmed S. Darwish" <darwish.07@...il.com>,
linux-input@...ey.karlin.mff.cuni.cz,
linux-joystick@...ey.karlin.mff.cuni.cz,
linux-kernel@...r.kernel.org, akpm@...ux-foundation.org,
"Jean Delvare" <khali@...ux-fr.org>
Subject: Re: [PATCH try #3] Input/Joystick Driver: add support AD7142 joystick driver
Hi Bryan,
On 10/15/07, Bryan Wu <bryan.wu@...log.com> wrote:
> +
> +static int ad7142_thread(void *nothing)
> +{
> + do {
> + wait_for_completion(&ad7142_completion);
> + ad7142_decode();
> + enable_irq(CONFIG_BFIN_JOYSTICK_IRQ_PFX);
> + } while (!kthread_should_stop());
> +
No, this is not going to work well:
- you at least need to reinitialize the completion before enabling
IRQ, otherwise you will spin in a very tight loop
- if noone would touch the joystick ad7142_clsoe would() block
infinitely because noone would signal the completion and
ad7142_thread() would never stop.
Completion is just not a good abstraction here... Please use work
abstraction and possibly a separate workqueue.
> +
> + ad7142_task = kthread_run(ad7142_thread, NULL, "ad7142_task");
> + if (IS_ERR(ad7142_task)) {
> + printk(KERN_ERR "serio: Failed to start kseriod\n");
kseriod?
> + return PTR_ERR(ad7142_task);
> + }
> + return 0;
> +}
> +
> +static void ad7142_close(struct input_dev *dev)
> +{
Don't you need to write something over i2c to tell the device to shut
down? As it is now I expect the device to continue raising its IRQ
until kernel decides that it is unhandled and should be ignored.
> + free_irq(CONFIG_BFIN_JOYSTICK_IRQ_PFX, ad7142_interrupt);
Ok, so you freeing IRQ here, but it is allocated in ad7142_probe().
What happen if you try to open device after it was closed?
> + kthread_stop(ad7142_task);
> +}
> +
> +static int __init ad7142_init(void)
> +{
> + return i2c_add_driver(&ad7142_driver);
> +}
> +
> +static void __exit ad7142_exit(void)
> +{
> + i2c_del_driver(&ad7142_driver);
> + input_unregister_device(ad7142_dev);
input_unregister_device() should be in ad7142_detach_client? I am not
sure i2c - there seems to be 2 interface styles and you probably need
to use the new one. I am CC-inj Jean on this.
> +}
> +
> +module_init(ad7142_init);
> +module_exit(ad7142_exit);
> --
> 1.5.3.4
>
--
Dmitry
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists