Re: [PATCH] power management: change /sys/power/disk display

["Rafael J. Wysocki" <rjw@sisk.pl>]

On Thursday, 12 April 2007 02:37, Johannes Berg wrote:
> This patch changes /sys/power/disk to display all valid modes
> as well as the currently selected one in a fashion known from
> the LED subsystem.
> 
> Signed-off-by: Johannes Berg <johannes@sipsolutions.net>

Looks good to me, but ... (see below)

> ---
> This changes userspace API, but it is apparently not used much (we asked
> some userspace developers)
> 
>  Documentation/power/interface.txt |    8 ++++++--
>  kernel/power/disk.c               |   34 +++++++++++++++++++++++++++++++---
>  2 files changed, 37 insertions(+), 5 deletions(-)
> 
> --- wireless-dev.orig/kernel/power/disk.c	2007-04-11 18:01:08.389481358 +0200
> +++ wireless-dev/kernel/power/disk.c	2007-04-11 18:01:10.109481358 +0200
> @@ -322,7 +322,34 @@ static const char * const pm_disk_modes[
>  
>  static ssize_t disk_show(struct subsystem * subsys, char * buf)
>  {
> -	return sprintf(buf, "%s\n", pm_disk_modes[pm_disk_mode]);
> +	int i;
> +	char *start = buf;
> +
> +	for (i = PM_DISK_PLATFORM; i < PM_DISK_MAX; i++) {
> +		if (!pm_disk_modes[i])
> +			continue;
> +		switch (i) {
> +		case PM_DISK_SHUTDOWN:
> +		case PM_DISK_REBOOT:
> +		case PM_DISK_TEST:
> +		case PM_DISK_TESTPROC:
> +			break;
> +		default:
> +			if (pm_ops && pm_ops->enter &&
> +			    (i == pm_ops->pm_disk_mode))
> +				break;
> +			/* not a valid mode, continue with loop */
> +			continue;
> +		}
> +		if (i == pm_disk_mode)
> +			buf += sprintf(buf, "[%s]", pm_disk_modes[i]);
> +		else
> +			buf += sprintf(buf, "%s", pm_disk_modes[i]);
> +		if (i+1 != PM_DISK_MAX)
> +			buf += sprintf(buf, " ");
> +	}
> +	buf += sprintf(buf, "\n");
> +	return buf-start;
>  }
>  
>  
> @@ -363,8 +390,9 @@ static ssize_t disk_store(struct subsyst
>  		error = -EINVAL;
>  	}
>  
> -	pr_debug("PM: suspend-to-disk mode set to '%s'\n",
> -		 pm_disk_modes[mode]);
> +	if (!error)
> +		pr_debug("PM: suspend-to-disk mode set to '%s'\n",
> +			 pm_disk_modes[mode]);
>  	mutex_unlock(&pm_mutex);
>  	return error ? error : n;
>  }

.. this is an additional bugfix, right?  If so, can you please separate it from
this patch?

> --- wireless-dev.orig/Documentation/power/interface.txt	2007-04-11 18:01:08.389481358 +0200
> +++ wireless-dev/Documentation/power/interface.txt	2007-04-11 18:01:10.109481358 +0200
> @@ -34,8 +34,12 @@ for 5 seconds, resume devices, unfreeze 
>  we are able to look in the log messages and work out, for example, which code
>  is being slow and which device drivers are misbehaving.
>  
> -Reading from this file will display what the mode is currently set
> -to. Writing to this file will accept one of
> +Reading from this file will display all supported modes and the currently
> +selected one in brackets, for example
> +
> +	[shutdown] reboot test testproc
> +
> +Writing to this file will accept one of
>  
>         'platform' (only if the platform supports it)
>         'shutdown'

Greetings,
Rafael