x86: tsc: Remove unneeded DMI-based blacklisting

x86: tsc: Remove unneeded DMI-based blacklisting

[Tero Roponen]

The blacklist was added in response to my bug report
(http://lkml.org/lkml/2006/1/19/362) and has never
contained more than the one entry describing my old
now dead ThinkPad 380XD laptop. As found out later
(http://lkml.org/lkml/2007/11/29/50), this special
treatment has been unnecessary for a long time, so
it can be removed.

Signed-off-by: Tero Roponen <tero.roponen@gmail.com>

diff --git a/arch/x86/kernel/tsc.c b/arch/x86/kernel/tsc.c
index 6cc6922..5c45c62 100644
--- a/arch/x86/kernel/tsc.c
+++ b/arch/x86/kernel/tsc.c
@@ -5,7 +5,6 @@
 #include <linux/timer.h>
 #include <linux/acpi_pmtmr.h>
 #include <linux/cpufreq.h>
-#include <linux/dmi.h>
 #include <linux/delay.h>
 #include <linux/clocksource.h>
 #include <linux/percpu.h>
@@ -800,27 +799,6 @@ void mark_tsc_unstable(char *reason)
 
 EXPORT_SYMBOL_GPL(mark_tsc_unstable);
 
-static int __init dmi_mark_tsc_unstable(const struct dmi_system_id *d)
-{
-	printk(KERN_NOTICE "%s detected: marking TSC unstable.\n",
-			d->ident);
-	tsc_unstable = 1;
-	return 0;
-}
-
-/* List of systems that have known TSC problems */
-static struct dmi_system_id __initdata bad_tsc_dmi_table[] = {
-	{
-		.callback = dmi_mark_tsc_unstable,
-		.ident = "IBM Thinkpad 380XD",
-		.matches = {
-			DMI_MATCH(DMI_BOARD_VENDOR, "IBM"),
-			DMI_MATCH(DMI_BOARD_NAME, "2635FA0"),
-		},
-	},
-	{}
-};
-
 static void __init check_system_tsc_reliable(void)
 {
 #ifdef CONFIG_MGEODE_LX
@@ -1010,8 +988,6 @@ void __init tsc_init(void)
 	lpj_fine = lpj;
 
 	use_tsc_delay();
-	/* Check and install the TSC clocksource */
-	dmi_check_system(bad_tsc_dmi_table);
 
 	if (unsynchronized_tsc())
 		mark_tsc_unstable("TSCs unsynchronized");

Re: x86: tsc: Remove unneeded DMI-based blacklisting

[john stultz]

On Tue, 2011-05-31 at 10:24 +0300, Tero Roponen wrote:
> The blacklist was added in response to my bug report
> (http://lkml.org/lkml/2006/1/19/362) and has never
> contained more than the one entry describing my old
> now dead ThinkPad 380XD laptop. As found out later
> (http://lkml.org/lkml/2007/11/29/50), this special
> treatment has been unnecessary for a long time, so
> it can be removed.
> 
> Signed-off-by: Tero Roponen <tero.roponen@gmail.com>

Wow. Those are old mails! Thanks for following up here to clarify that
these bits aren't needed. 

I'll apply and queue this for 3.1.

thanks
-john