Messages in this thread | | | Subject | Re: [PATCH] clocksource: mips-gic-timer: fix clocksource counter width | From | Felix Fietkau <> | Date | Wed, 28 Feb 2018 10:19:25 +0100 |
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On 2018-02-28 09:56, Thomas Gleixner wrote: > On Wed, 21 Feb 2018, Felix Fietkau wrote: > >> This code needs to use ffs instead of fls on the mask to determine the >> shift for reading the GIC_CONFIG_COUNTBITS field. > > Why? >> count_width = read_gic_config() & GIC_CONFIG_COUNTBITS; >> - count_width >>= __fls(GIC_CONFIG_COUNTBITS); >> + count_width >>= __ffs(GIC_CONFIG_COUNTBITS); This code is trying to extract the GIC_CONFIG_COUNTBITS field from read_gic_config(), so it needs to shift count_width right by the index of the least significant bit (__ffs) instead of the most significant bit (__fls) of the field mask.
- Felix
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