Messages in this thread |  | | Date | Thu, 26 Oct 2000 19:03:09 +0200 | From | Vojtech Pavlik <> | Subject | Re: Possible critical VIA vt82c686a chip bug (private question) |
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On Thu, Oct 26, 2000 at 12:04:21PM -0400, Richard B. Johnson wrote:
> ../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.
Well, at least on 2.4.0-test9, the above timing code is #ifed to DISK_RECOVERY_TIME > 0, which in turn is #defined to 0 in include/linux/ide.h.
So this is not our problem here. Anyway I guess it's time to hunt for i8259 accesses in the kernel that lack the necessary spinlock, even when they're not probably the cause of the problem we see here.
-- Vojtech Pavlik SuSE Labs - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org Please read the FAQ at http://www.tux.org/lkml/
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