[PATCH] Mark TSC on GeodeLX reliable

The Geode can safely use the TSC for highres, since:

1) Does not support frequency scaling,

2) The TSC _does_ count when the CPU is halted.  Furthermore, the Geode
   supports a mode called "suspension on halt", where Suspend mode (which
   interacts with the power management states) is entered.  TSC counting
   during suspend mode is controlled by bit 8 of the Bus Controller
   Configuration Register #0 (thanks Tom!).

3) no SMP :)

Check if "RTSC counts during suspension" and remove the requirement for
verification, so the clocksource code can safely select it as an timesource
for the highres timers subsystem.

Signed-off-by: Marcelo Tosatti <marcelo@kvack.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cc: john stultz <johnstul@us.ibm.com>
Cc: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

This commit is contained in:

Marcelo Tosatti

2007-02-16 01:27:44 -08:00

committed by

Linus Torvalds

parent 5d8b34fdcb

commit 07190a08ee

2 changed files with 23 additions and 0 deletions

									
										include/asm-i386/msr.h
									
		+3
		
												View File
												
				@@ -307,4 +307,7 @@ static inline void wrmsrl (unsigned long msr, unsigned long long val)

				#define MSR_CORE_PERF_GLOBAL_CTRL	0x38f

				#define MSR_CORE_PERF_GLOBAL_OVF_CTRL	0x390

				/* Geode defined MSRs */

				#define MSR_GEODE_BUSCONT_CONF0         0x1900

				#endif /* __ASM_MSR_H */