[FIX] apm.c: ignore_normal_resume is set to 1 a bit too late

[FIX] apm.c: ignore_normal_resume is set to 1 a bit too late

[Thomas Hood]

This message contains a fix for a bug in the apm driver.

A bug report was submitted to the Debian BTS saying that on the
submitter's system the apmd proxy script was being run twice on resume.

Having seen exactly the same problem some years ago and knowing that the
solution then was to ensure that the ignore_normal_resume flag got set
before there was any chance of an APM RESUME event being processed, I
checked the current apm.c and I found that ignore_normal_resume was once
again being set too late.  I asked the submitter to move the line where
the flag was set and he reported that this change solved the problem.  I
append the message in question.  The line numbers I mention there are
for Linux 2.6.11.

Please make the indicated change to the apm driver.

-------- Forwarded Message --------
jdthood@aglu.demon.nl wrote to the submitter of Debian bug #310865:
> In arch/i386/kernel/apm.c there is at approximately line 1229:
> 
>         ignore_normal_resume = 1;
> 
> Move this up so that it occurs right after line 1222:
> 
>         err = set_system_power_state(APM_STATE_SUSPEND);
> 
> Let us know if that helps.


It does. Very nice.
I don't understand what I did and how it works. Will you try to
push that into kernel sources or is this no permanent fix?
-- 
Thomas Hood <jdthood@aglu.demon.nl>

[PATCH] apm.c: ignore_normal_resume is set a bit too late

[Thomas Hood]

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On Mon, 2005-06-13 at 22:20 +1000, Stephen Rothwell wrote:
> I am not using APM any more and have no way to test such a change.  So,
> can you please do a proper patch with comment and Signed-off-by line and
> send it to Andrew Morton (akpm@osdl.org) (and cc lkml, I guess).  When I
> see it, I will Ack it to Andrew.


Summary: apm: Prevent double APM resume on Thinkpad X31

This patch causes the ignore_normal_resume flag to be set slightly
earlier, before there is a chance that the apm driver will receive the
normal resume event from the BIOS.  (Addresses Debian bug #310865)

Signed-off-by: Thomas Hood <jdthood@yahoo.co.uk>

-- 
Thomas Hood <jdthood@aglu.demon.nl>

[-- Attachment #2: apm.c_double_resume_fix_20050613jdth1.patch --]
[-- Type: text/x-patch, Size: 554 bytes --]

--- kernel-source-2.6.11/arch/i386/kernel/apm.c_ORIG	2005-03-02 08:37:47.000000000 +0100
+++ kernel-source-2.6.11/arch/i386/kernel/apm.c	2005-06-13 14:59:51.000000000 +0200
@@ -1220,13 +1220,13 @@ static int suspend(int vetoable)
 
 	save_processor_state();
 	err = set_system_power_state(APM_STATE_SUSPEND);
+	ignore_normal_resume = 1;
 	restore_processor_state();
 
 	write_seqlock_irq(&xtime_lock);
 	spin_lock(&i8253_lock);
 	reinit_timer();
 	set_time();
-	ignore_normal_resume = 1;
 
 	spin_unlock(&i8253_lock);
 	write_sequnlock_irq(&xtime_lock);

Re: [FIX] apm.c: ignore_normal_resume is set to 1 a bit too late

[Jesper Juhl]

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On 6/13/05, Thomas Hood <jdthood@aglu.demon.nl> wrote:
> This message contains a fix for a bug in the apm driver.
> 
> A bug report was submitted to the Debian BTS saying that on the
> submitter's system the apmd proxy script was being run twice on resume.
> 
> Having seen exactly the same problem some years ago and knowing that the
> solution then was to ensure that the ignore_normal_resume flag got set
> before there was any chance of an APM RESUME event being processed, I
> checked the current apm.c and I found that ignore_normal_resume was once
> again being set too late.  I asked the submitter to move the line where
> the flag was set and he reported that this change solved the problem.  I
> append the message in question.  The line numbers I mention there are
> for Linux 2.6.11.
> 
> Please make the indicated change to the apm driver.
> 
> -------- Forwarded Message --------
> jdthood@aglu.demon.nl wrote to the submitter of Debian bug #310865:
> > In arch/i386/kernel/apm.c there is at approximately line 1229:
> >
> >         ignore_normal_resume = 1;
> >
> > Move this up so that it occurs right after line 1222:
> >
> >         err = set_system_power_state(APM_STATE_SUSPEND);
> >
> > Let us know if that helps.
> 
> 
> It does. Very nice.
> I don't understand what I did and how it works. Will you try to
> push that into kernel sources or is this no permanent fix?
> --
> Thomas Hood <jdthood@aglu.demon.nl>
> 

Here it is in the form of a patch against 2.6.12-rc6-mm1 for easier
merging - Stephen, Andrew, is this a valid fix? I don't know the apm
code well enough to properly judge.
(also attached since gmail tends to mangle inline patches)


Prevent double resume in apm.

Signed-off-by: Jesper juhl <jesper.juhl@gmail.com>
---

 arch/i386/kernel/apm.c |    2 +-
 1 files changed, 1 insertion(+), 1 deletion(-)

--- linux-2.6.12-rc6-mm1-orig/arch/i386/kernel/apm.c	2005-06-12
15:58:34.000000000 +0200
+++ linux-2.6.12-rc6-mm1/arch/i386/kernel/apm.c	2005-06-13
23:39:57.000000000 +0200
@@ -1222,6 +1222,7 @@ static int suspend(int vetoable)
 
 	save_processor_state();
 	err = set_system_power_state(APM_STATE_SUSPEND);
+	ignore_normal_resume = 1;
 	restore_processor_state();
 
 	local_irq_disable();
@@ -1229,7 +1230,6 @@ static int suspend(int vetoable)
 	spin_lock(&i8253_lock);
 	reinit_timer();
 	set_time();
-	ignore_normal_resume = 1;
 
 	spin_unlock(&i8253_lock);
 	write_sequnlock(&xtime_lock);



-- 
Jesper Juhl <jesper.juhl@gmail.com>
Don't top-post  http://www.catb.org/~esr/jargon/html/T/top-post.html
Plain text mails only, please      http://www.expita.com/nomime.html

[-- Warning: decoded text below may be mangled, UTF-8 assumed --]
[-- Attachment #2: prevent-double-resume-in-apm.patch --]
[-- Type: text/x-patch; name="prevent-double-resume-in-apm.patch", Size: 592 bytes --]

--- linux-2.6.12-rc6-mm1-orig/arch/i386/kernel/apm.c	2005-06-12 15:58:34.000000000 +0200
+++ linux-2.6.12-rc6-mm1/arch/i386/kernel/apm.c	2005-06-13 23:39:57.000000000 +0200
@@ -1222,6 +1222,7 @@ static int suspend(int vetoable)
 
 	save_processor_state();
 	err = set_system_power_state(APM_STATE_SUSPEND);
+	ignore_normal_resume = 1;
 	restore_processor_state();
 
 	local_irq_disable();
@@ -1229,7 +1230,6 @@ static int suspend(int vetoable)
 	spin_lock(&i8253_lock);
 	reinit_timer();
 	set_time();
-	ignore_normal_resume = 1;
 
 	spin_unlock(&i8253_lock);
 	write_sequnlock(&xtime_lock);