a bit smarter dmi-scan.c

Greetings.
First things first:
MERRY CHRISTMAS !!!

I couldn't pinpoint a maintainer responsible for this code, so here
goes...

linux/arch/i386/kernel/dmi-scan.c contains a bit of code that takes APM
specific decisions even when APM isn't in the kernel. For that matter, even setup.c maintains a apm_info variable of type (struct apm_info) that's created regardless of whether APM is enabled in the kernel or not. Is this a deliberate decision or am I missing something?
Yes, I know that it doesn't hurt, but it still looks funny when a a
function in dmi-scan.c declares "IBM machine detected. Enabling interrupts during APM BIOS calls." even when APM is disabled in the _BIOS_.
Should we make the APM specific lines in linux/arch/i386/kernel/setup.c
(this code fills up the apm_info struct) conditional? I didn't touch it because the gains are insignificant. It would be better to do this stuff if the kernel finds an APM compliant (or non-compliant ;) BIOS.
I _know_ that dmi-scan.c can be improved further, but I only want to
bring up a point, not start a [un]holy war or feed the trolls (no offense ;)

Here's the patch for quick reference. It's also attached. (please observe the proper patch -p{x} option)

@@ -255,26 +255,29 @@
 
 static __init int set_realmode_power_off(struct dmi_blacklist *d)
 {
+#if defined (CONFIG_APM)
        if (apm_info.realmode_power_off == 0)
        {
                apm_info.realmode_power_off = 1;
                printk(KERN_INFO "%s bios detected. Using realmode power

off only.\n", d->ident);
        }
+#endif
        return 0;

}

-
/*
* Some laptops require interrupts to be enabled during APM calls */

static __init int set_apm_ints(struct dmi_blacklist *d) {
+#if defined (CONFIG_APM)

        if (apm_info.allow_ints == 0)
        {
                apm_info.allow_ints = 1;
                printk(KERN_INFO "%s machine detected. Enabling interrup
ts during APM calls.\n", d->ident);
        }
+#endif
        return 0;

}

@@ -284,15 +287,16 @@

static __init int apm_is_horked(struct dmi_blacklist *d) {
+#if defined (CONFIG_APM)

        if (apm_info.disabled == 0)
        {
                apm_info.disabled = 1;
                printk(KERN_INFO "%s machine detected. Disabling APM.\n"
, d->ident);
        }
+#endif
        return 0;

}

- * Check for clue free BIOS implementations who use
* the following QA technique
@@ -311,10 +315,12 @@

static __init int broken_apm_power(struct dmi_blacklist *d) {
+#if defined (CONFIG_APM)
apm_info.get_power_status_broken = 1; printk(KERN_WARNING "BIOS strings suggest APM bugs, disabling po
wer status reporting.\n");
+#endif

        return 0;

-}
+}

/*
* Check for a Sony Vaio system
@@ -341,8 +347,10 @@

static __init int swab_apm_power_in_minutes(struct dmi_blacklist *d) {
+#if defined (CONFIG_APM)
apm_info.get_power_status_swabinminutes = 1; printk(KERN_WARNING "BIOS strings suggest APM reports battery li
fe in minutes and wrong byte order.\n");
+#endif

        return 0;

}
/*

-----------------
Thanks, and again, Merry Christmas and Happy New Year!

- ioj

~~~~
Ask not of race, but ask of conduct:
From the stick is born the sacred fire:
The wise ascetic, though lowly born,
Is noble in his modest self-control.
- Gotama Buddha
.

@@ -255,26 +255,29 @@
 
 static __init int set_realmode_power_off(struct dmi_blacklist *d)
 {
+#if defined (CONFIG_APM)
        if (apm_info.realmode_power_off == 0)
        {
                apm_info.realmode_power_off = 1;
                printk(KERN_INFO "%s bios detected. Using realmode poweroff only.\n", d->ident);
        }
+#endif
        return 0;
 }
 
-
 /* 
  * Some laptops require interrupts to be enabled during APM calls 
  */
 
 static __init int set_apm_ints(struct dmi_blacklist *d)
 {
+#if defined (CONFIG_APM)
 	if (apm_info.allow_ints == 0)
 	{
 		apm_info.allow_ints = 1;
 		printk(KERN_INFO "%s machine detected. Enabling interrupts during APM calls.\n", d->ident);
 	}
+#endif
 	return 0;
 }
 

@@ -284,15 +287,16 @@
 
 static __init int apm_is_horked(struct dmi_blacklist *d)
 {
+#if defined (CONFIG_APM)
 	if (apm_info.disabled == 0)
 	{
 		apm_info.disabled = 1;
 		printk(KERN_INFO "%s machine detected. Disabling APM.\n", d->ident);
 	}
+#endif
 	return 0;
 }
 
-
 /*
  *  Check for clue free BIOS implementations who use
  *  the following QA technique

@@ -311,10 +315,12 @@
 
 static __init int broken_apm_power(struct dmi_blacklist *d)
 {
+#if defined (CONFIG_APM)
 	apm_info.get_power_status_broken = 1;
 	printk(KERN_WARNING "BIOS strings suggest APM bugs, disabling power status reporting.\n");
+#endif
 	return 0;
-}		
+}
 
 /*
  * Check for a Sony Vaio system

@@ -341,8 +347,10 @@
  
 static __init int swab_apm_power_in_minutes(struct dmi_blacklist *d)
 {
+#if defined (CONFIG_APM)
 	apm_info.get_power_status_swabinminutes = 1;
 	printk(KERN_WARNING "BIOS strings suggest APM reports battery life in minutes and wrong byte order.\n");
+#endif
 	return 0;
 }
 

Hi,

Cheers,
Stephen Rothwell                    [email protected]
http://www.canb.auug.org.au/~sfr/