From: "Dmitry Torokhov" <dmitry.torokhov@gmail.com>
To: bryan.wu@analog.com
Cc: "Andrey Panin" <pazke@donpac.ru>, "Roel Kluin" <12o3l@tiscali.nl>,
"Ahmed S. Darwish" <darwish.07@gmail.com>,
linux-input@atrey.karlin.mff.cuni.cz,
linux-joystick@atrey.karlin.mff.cuni.cz,
linux-kernel@vger.kernel.org, akpm@linux-foundation.org,
"Jean Delvare" <khali@linux-fr.org>
Subject: Re: [PATCH try #3] Input/Joystick Driver: add support AD7142 joystick driver
Date: Mon, 15 Oct 2007 11:48:17 -0400 [thread overview]
Message-ID: <d120d5000710150848t1993b0aavbbc0cd7971e3ef3e@mail.gmail.com> (raw)
In-Reply-To: <1192459625.6215.17.camel@roc-laptop>
Hi Bryan,
On 10/15/07, Bryan Wu <bryan.wu@analog.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
next prev parent reply other threads:[~2007-10-15 15:48 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-10-15 14:47 [PATCH try #3] Input/Joystick Driver: add support AD7142 joystick driver Bryan Wu
2007-10-15 15:48 ` Dmitry Torokhov [this message]
2007-10-15 17:24 ` Bryan Wu
2007-10-15 17:40 ` Dmitry Torokhov
2007-10-16 5:51 ` Bryan Wu
2007-10-16 16:53 ` Dmitry Torokhov
2007-10-15 18:27 ` Ahmed S. Darwish
2007-10-16 6:08 ` Bryan Wu
2007-10-16 16:40 ` Ahmed S. Darwish
2007-10-15 19:35 ` Jean Delvare
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