[PATCH v9 0/4] arm64: arch_timer: Add workaround for hisilicon-161010101 erratum

[Daniel Lezcano]

On 19/01/2017 14:35, Ding Tianhong wrote:
> Erratum Hisilicon-161010101 says that the ARM generic timer counter "has the
> potential to contain an erroneous value when the timer value changes".
> Accesses to TVAL (both read and write) are also affected due to the implicit counter
> read.  Accesses to CVAL are not affected.
> 
> The workaround is to reread the system count registers until the value of the second
> read is larger than the first one by less than 32, the system counter can be guaranteed
> not to return wrong value twice by back-to-back read and the error value is always larger
> than the correct one by 32. Writes to TVAL are replaced with an equivalent write to CVAL.

Why not use another clocksource instead of adding a workaround with a
non negligible overhead and more complexity in the code ?


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