Messages in this thread | | | Subject | RE: [PATCH] 1/3 Dynamic cpufreq governor and updates to ACPI P-state driver | Date | Tue, 21 Oct 2003 11:57:58 -0700 | From | "Pallipadi, Venkatesh" <> |
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> -----Original Message----- > From: Ducrot Bruno [mailto:ducrot@poupinou.org] > Sent: Tuesday, October 21, 2003 10:56 AM > > > It will work any processor > > that is ACPI compatible and again there are no specific > > checks for Intel here. > > > > On a K7 with powernow for example, perf_ctrl and perf_data > will be MSR 0 > with your patch, that do not make sence. > Even if you know the correct MSRs, the values for 'control' > and 'status' > in _PSS packages will be only bit-fields, and they can *not* be > written nor read directly to the (correct) MSRs (again for K7 > powernow). > > This is because the FfixedHW is only an indication that a CPU specific > 'feature' (even though already somehow defined in ACPI like P-state, > C-state, etc.) have to be handled by the OS in a non-acpi driver, as > per ACPI spec, and that will be dependant of the CPU. >
Agree with most of your comments. Current ACPI P-state driver ignored everything other than SYSTEM_IO. And we are trying to add support for FIXED_HW. I was unaware of any other CPU using ACPI PCT FIXED_HW to mean anything other than MSR. As you mentioned, if K7 indeed exports some ACPI-PCT information to mean something else, then that is a real bug in my patch. I will add CPU specific abstraction to handle FIXED_HW get/set functions in the next revision of the patch.
Thanks, -Venkatesh - 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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