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authorThomas Gleixner <tglx@linutronix.de>2008-08-14 12:17:06 +0200
committerThomas Gleixner <tglx@linutronix.de>2008-08-14 13:23:45 +0200
commita6825f1c1fa83b1e92b6715ee5771a4d6524d3b9 (patch)
tree597cc3ed1c221c4ea76bdb51c327604b8115b85f /include/asm-um/cputime.h
parenta58f03b07539f6575adaa011712fa139c9343742 (diff)
x86: hpet: workaround SB700 BIOS
AMD SB700 based systems with spread spectrum enabled use a SMM based HPET emulation to provide proper frequency setting. The SMM code is initialized with the first HPET register access and takes some time to complete. During this time the config register reads 0xffffffff. We check for max. 1000 loops whether the config register reads a non 0xffffffff value to make sure that HPET is up and running before we go further. A counting loop is safe, as the HPET access takes thousands of CPU cycles. On non SB700 based machines this check is only done once and has no side effects. Based on a quirk patch from: crane cai <crane.cai@amd.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'include/asm-um/cputime.h')
0 files changed, 0 insertions, 0 deletions