Hi.
On Tue, 2009-01-13 at 17:27 -0800, Arve Hjønnevåg wrote:> Signed-off-by: Arve Hjønnevåg <arve@xxxxxxxxxxx>> ---> include/linux/earlysuspend.h | 56 ++++++++++++++++++++++++++++++++++++++++++> 1 files changed, 56 insertions(+), 0 deletions(-)> create mode 100755 include/linux/earlysuspend.h> > diff --git a/include/linux/earlysuspend.h b/include/linux/earlysuspend.h> new file mode 100755> index 0000000..8343b81> --- /dev/null> +++ b/include/linux/earlysuspend.h> @@ -0,0 +1,56 @@> +/* include/linux/earlysuspend.h> + *> + * Copyright (C) 2007-2008 Google, Inc.> + *> + * This software is licensed under the terms of the GNU General Public> + * License version 2, as published by the Free Software Foundation, and> + * may be copied, distributed, and modified under those terms.> + *> + * This program is distributed in the hope that it will be useful,> + * but WITHOUT ANY WARRANTY; without even the implied warranty of> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the> + * GNU General Public License for more details.> + *> + */> +> +#ifndef _LINUX_EARLYSUSPEND_H> +#define _LINUX_EARLYSUSPEND_H> +> +#ifdef CONFIG_HAS_EARLYSUSPEND> +#include <linux/list.h>> +#endif
Just #include anyway - it doesn't matter if it doesn't get used in somecircumstances.
> +> +/* The early_suspend structure defines suspend and resume hooks to be called> + * when the user visible sleep state of the system changes, and a level to> + * control the order. They can be used to turn off the screen and input> + * devices that are not used for wakeup.> + * Suspend handlers are called in low to high level order, resume handlers are> + * called in the opposite order. If, when calling register_early_suspend,> + * the suspend handlers have already been called without a matching call to the> + * resume handlers, the suspend handler will be called directly from> + * register_early_suspend. This direct call can violate the normal level order.> + */
Registering can happen while we're suspending and resuming? Thatpotential variation in ordering sounds dangerous as far as opportunitiesfor race conditions goes.
> +enum {> + EARLY_SUSPEND_LEVEL_BLANK_SCREEN = 50,> + EARLY_SUSPEND_LEVEL_STOP_DRAWING = 100,> + EARLY_SUSPEND_LEVEL_DISABLE_FB = 150,> +};> +struct early_suspend {> +#ifdef CONFIG_HAS_EARLYSUSPEND> + struct list_head link;> + int level;> + void (*suspend)(struct early_suspend *h);> + void (*resume)(struct early_suspend *h);
Could these functions ever potentially fail in way that you'd wantcallers to know? If so, you might want a non void return value.
> +#endif> +};> +> +#ifdef CONFIG_HAS_EARLYSUSPEND> +void register_early_suspend(struct early_suspend *handler);> +void unregister_early_suspend(struct early_suspend *handler);> +#else> +#define register_early_suspend(handler) do { } while (0)> +#define unregister_early_suspend(handler) do { } while (0)> +#endif> +> +#endif> +
Regards,
Nigel
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