Messages in this thread | | | From | "Woller, Thomas" <> | Subject | RE: Incorrect mdelay() results on Power Managed Machines x86 | Date | Thu, 22 Mar 2001 17:26:05 -0600 |
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> > I wonder if there is a way to modify mdelay to use a kernel timer if > > interval > 10msec? I am not familiar with this section of the kernel, > but I > > do know that Microsoft's similar function KeStallExecutionProcessor is > not > > recommended for more than 50 *micro*seconds. > >>Basically the same kind of recommendation applies. But as with all rules its >>sometimes appropriate to break it
thanks, i just tested the "notsc" option (.config has CONFIG_X86_TSC enabled=y, but CONFIG_M586TSC is not enabled.. if that's ok), but this time I booted and kept the machine on battery power the ENTIRE time, i had not tried this before. the MHZ value Detected in time.c is 132Mhz (down from 500Mhz if not on battery power). but the interesting thing that i just noticed is that the mdelay() wait time, is STILL about 25% of what it should delay. i use 10000 (for a 10 second delay) and get only about 2-3 seconds out of it. this smaller delay occurs with or without "notsc" on the boot line. now, i did not expect this behaviour if i did not plug in to get more CPU speed, with the calculated cpu rate when on battery power. i expected that mdelay() would function properly with the appropriate wait time if i booted and stayed on battery power, at the same reduced CPU frequency. Alan, you might have answered this in your first post but i don't under the INTEL speedstep logic to understand if this is expected behaviour. but the bottom line is that my delay of 700 milleseconds in the driver fails if i boot and stay on battery power exclusively. did anyone else expect this behaviour? - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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