Re: swsusp: documentation fixes

[Nigel Cunningham <ncunningham@cyclades.com>]

Hi.

On Fri, 2005-12-16 at 20:58, Pavel Machek wrote:
> Documentation and printk updates. Document "modular SATA" trap.
> 
> Signed-off-by: Pavel Machek <pavel@suse.cz>
> 
> ---
> commit bd607a6d78db651cf6e4b199eae3476f4c935db6
> tree 5a781c7cfcfb78a3d3cab2c518ea00bf46ab6e6f
> parent 45a5301637600fc7e517c3308e957b3fac7cfd86
> author <pavel@amd.(none)> Fri, 16 Dec 2005 11:45:58 +0100
> committer <pavel@amd.(none)> Fri, 16 Dec 2005 11:45:58 +0100
> 
>  Documentation/power/swsusp.txt |   18 +++++++++++-------
>  Documentation/power/video.txt  |    1 +
>  kernel/power/swsusp.c          |    2 +-
>  3 files changed, 13 insertions(+), 8 deletions(-)
> 
> diff --git a/Documentation/power/swsusp.txt b/Documentation/power/swsusp.txt
> --- a/Documentation/power/swsusp.txt
> +++ b/Documentation/power/swsusp.txt
> @@ -27,13 +27,11 @@ echo shutdown > /sys/power/disk; echo di
>  
>  echo platform > /sys/power/disk; echo disk > /sys/power/state
>  
> -
> -Encrypted suspend image:
> -------------------------
> -If you want to store your suspend image encrypted with a temporary
> -key to prevent data gathering after resume you must compile
> -crypto and the aes algorithm into the kernel - modules won't work
> -as they cannot be loaded at resume time.
> +. If you have SATA disks, you'll need recent kernels with SATA suspend
> +support. For suspend and resume to work, make sure your disk drivers
> +are built into kernel -- not modules. [There's way to make
> +suspend/resume with modular disk drivers, see FAQ, but you should
> +better not do that.]
>  
> 
>  Article about goals and implementation of Software Suspend for Linux
> @@ -328,4 +326,10 @@ init=/bin/bash, then swapon and starting
>  usually does the trick. Then it is good idea to try with latest
>  vanilla kernel.
>  
> +Q: How can RH ship a swsusp-supporting kernel with modular SATA
> +drivers?
>  
> +A: Well, it can be done, load the drivers, then do echo into resume
> +file from initrd. Be sure not to mount anything, not even read-only
> +mount, or you are going to loose your filesystem same way Dave Jones
> +did.

Quick solution to this - store the root filesystem's dev_t in the image
header. If it's mounted when doing the sanity check, refuse to resume.

Regards,

Nigel

> diff --git a/Documentation/power/video.txt b/Documentation/power/video.txt
> --- a/Documentation/power/video.txt
> +++ b/Documentation/power/video.txt
> @@ -132,6 +132,7 @@ Sony Vaio PCG-F403		??? (*)
>  Sony Vaio PCG-N505SN		??? (*)
>  Sony Vaio PCG-GRT995MP		none (1), works with 'nv' X driver
>  Sony Vaio vgn-s260		X or boot-radeon can init it (5)
> +Sony Vaio vgn-S580BH		vga=normal, but suspend from X. Console will be blank unless you return to X. 
>  Sony Vaio vgn-FS115B		s3_bios (2),s3_mode (4)
>  Toshiba Libretto L5		none (1)
>  Toshiba Portege 3020CT		s3_mode (3)
> diff --git a/kernel/power/swsusp.c b/kernel/power/swsusp.c
> --- a/kernel/power/swsusp.c
> +++ b/kernel/power/swsusp.c
> @@ -988,7 +988,7 @@ int swsusp_check(void)
>  	if (!error)
>  		pr_debug("swsusp: resume file found\n");
>  	else
> -		pr_debug("swsusp: Error %d check for resume file\n", error);
> +		pr_debug("swsusp: Error %d checking for resume file (are your disk drivers built-in?)\n", error);
>  	return error;
>  }
>  
--