linux-bl808/arch
Thomas Gleixner 6b3964cde7 [PATCH] i386: clockevents fix breakage on Geode/Cyrix PIT implementations
The PIT has no dedicated mode for shut down. The only way to disable PIT
is to put it into one shot mode. AMD implementations of PIT on Geode
(also observed on Cyrix) are confused by an "empty" transition from
CLOCK_EVT_MODE_UNUSED to CLOCK_EVT_MODE_SHUTDOWN, which puts the PIT
into one shot mode momentarily.

I realized after staring helpless at the bug report
http://bugzilla.kernel.org/show_bug.cgi?id=8027 for quite a while, that
the only change, which might influence the bogomips calibration, is the
above transition during the PIT initialization.

Avoiding the unnecessary switch to oneshot and later to periodic mode
fixes the weird bogomips value and also the resulting slowness.

The fix is confirmed on OLPC and another Geode based box.

Note: this is unrelated to the Dual Core problem discussed here:
http://lkml.org/lkml/2007/3/17/48

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-03-22 19:33:30 -07:00
..
alpha
arm Merge master.kernel.org:/home/rmk/linux-2.6-arm 2007-03-19 20:05:16 -07:00
arm26
avr32 [PATCH] gpio_direction_output() needs an initial value 2007-03-16 19:25:04 -07:00
cris
frv
h8300
i386 [PATCH] i386: clockevents fix breakage on Geode/Cyrix PIT implementations 2007-03-22 19:33:30 -07:00
ia64 [IA64] Fix wrong /proc/iomem on SGI Altix 2007-03-20 13:54:44 -07:00
m32r
m68k
m68knommu
mips [MIPS] Export except_vec_vi_{mori,lui,ori} as text symbols. 2007-03-19 20:22:44 +00:00
parisc
powerpc
ppc
s390 [S390] Wire up sys_utimes. 2007-03-19 13:19:07 +01:00
sh
sh64
sparc
sparc64 [SPARC64]: store-init needs trailing membar. 2007-03-19 13:27:33 -07:00
um
v850
x86_64 [PATCH] Fix atomicity of TIF update in flush_thread() for x86_64 2007-03-18 11:35:08 -07:00
xtensa