Re: [PATCH] x86/tsc: Always Running Timer (ART) nanoseconds clocksource

Hi Thomas, Thank you for your review comments. Please find my answers inline. On Thu, 2018-03-01 at 12:40 +0100, Thomas Gleixner wrote: > On Wed, 28 Feb 2018, Rajvi Jingar wrote: > > Subject: x86/tsc: Always Running Timer (ART) nanoseconds clocksource > > Please don't

[PATCH v2] x86/tsc: Convert ART in nanoseconds to TSC.

(v1 added redundant hardcode just for the ART.ns conversion) * use tsc_khz for TSC conversion, also requires driver to check X86_FEATURE_TSC_KNOWN_FREQ (v1 used CPUID[15H].ECX value directly) Signed-off-by: Rajvi Jingar Suggested-by: Christopher S. Hall --- arch/x86/include/asm/tsc.h | 1

Re: [PATCH v2] x86/tsc: Convert ART in nanoseconds to TSC.

Hi Thomas, Thank you for your comments. On Thu, 2018-03-08 at 15:25 +0100, Thomas Gleixner wrote: > On Tue, 6 Mar 2018, Rajvi Jingar wrote: > > Device drivers use get_device_system_crosststamp() to produce > > precise > > system/device cross-timestamps. The PHC clock and ALS

[PATCH v3] x86/tsc: Convert ART in nanoseconds to TSC.

/ 1e6 This is valid when CPU feature flag X86_FEATURE_TSC_KNOWN_FREQ is set indicating the tsc_khz is derived from CPUID[15H]. Drivers should check that this flag is set before conversion to TSC is attempted. Signed-off-by: Rajvi Jingar Suggested-by: Christopher S. Hall --- Changes from v2: * add

[PATCH] x86/tsc: Always Running Timer (ART) nanoseconds clocksource

Nominal Core Crystal Clock Frequency such that: ART_value (in ticks) = (cryst_freq * ART.ns) / 1e9 Add a special case for Goldmont-based platform (which returns cryst_freq 0) to manually set the frequency to 19.2MHz. Signed-off-by: Rajvi Jingar Signed-off-by: Christopher S. Hall --- arch/x86

[tip:x86/timers] x86/tsc: Convert ART in nanoseconds to TSC

Commit-ID: fc804f65d46236c211f530174904c1ed70db5888 Gitweb: https://git.kernel.org/tip/fc804f65d46236c211f530174904c1ed70db5888 Author: Rajvi Jingar AuthorDate: Thu, 8 Mar 2018 09:28:36 -0800 Committer: Thomas Gleixner CommitDate: Fri, 16 Mar 2018 15:14:35 +0100 x86/tsc: Convert ART