tree 6787e6674fc52b1b31032cfa3edcf40034bf6bf0
parent 4221133845f81ab4428c79a89e37be2c87624c1a
author Vojtech Pavlik <vojtech@suse.cz> 1151323115 +0200
committer Linus Torvalds <torvalds@g5.osdl.org> 1151344099 -0700

[PATCH] x86_64: Explain why HPET T0_CMP register is written twice

After writing the CFG register, the first value written to the T0_CMP
register is the value at which next interrupt should be triggered, every
value after that sets the period of the interrupt. For that reason, the code
needs to write the value twice - to set both the phase and period.

[AK: I had already figured it out by myself, but it's still useful
to have a comment for this.]

Signed-off-by: Vojtech Pavlik <vojtech@suse.cz>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>