Messages in this thread |  | | Date | Thu, 26 Oct 2000 12:04:21 -0400 (EDT) | From | "Richard B. Johnson" <> | Subject | Re: Possible critical VIA vt82c686a chip bug (private question) |
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On 26 Oct 2000, Yoann Vandoorselaere wrote: > Vojtech Pavlik <vojtech@suse.cz> writes: [Snipped...]
../drivers/block/ide.c, line 162, on version 2.2.17 does bad things to the timer. It writes 0 to the control-word for timer 0. This does the following:
o Selects timer 0. o Latches the timer. o Selects mode 0. o Programs it to a 16 bit counter.
The result is a latched (stopped) counter. Bits 5 and 4 should have been selected. Then you read bits 0-7 from 0x40, followed by bits 8-15 from the same port.
Also, there is no spin-lock protecting access to these ports. If anybody else is mucking with the timer, all bets are off.
Cheers, Dick Johnson
Penguin : Linux version 2.2.17 on an i686 machine (801.18 BogoMips).
"Memory is like gasoline. You use it up when you are running. Of course you get it all back when you reboot..."; Actual explanation obtained from the Micro$oft help desk.
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