Messages in this thread | | | Subject | Re: [PATCHv2 3/4] arm-cci: Add routines to enable/disable all counters | From | "Suzuki K. Poulose" <> | Date | Thu, 5 Nov 2015 10:19:50 +0000 |
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On 05/11/15 10:14, Suzuki K. Poulose wrote: > On 04/11/15 18:28, Mark Rutland wrote: >> On Tue, Oct 20, 2015 at 02:05:25PM +0100, Suzuki K. Poulose wrote: >>> Adds helper routines to manipulate the counter controls for >>> all the counters on the CCI PMU.
>>> +static void pmu_disable_counters_ctrl(struct cci_pmu *cci_pmu, unsigned long *mask) >>> +{ >>> + int i; >>> + >>> + for (i = 0; i < cci_pmu->num_cntrs; i++) { >>> + clear_bit(i, mask); >>> + if (pmu_get_counter_ctrl(cci_pmu, i)) { >>> + set_bit(i, mask); >>> + pmu_disable_counter(cci_pmu, i); >>> + } >>> + } >>> +} >> >> I don't understand what's going on with the mask here. Why do we clear >> ieach bit when the only user (introduced in the next patch) explicitly >> clears the mask anyway? > > To be more precise, it should have been : > > if (pmu_get_counter_ctrl(cci_pmu, i)) { > set_bit(i, mask); > pmu_disable_counter(cci_pmu, i); > } else > clear_bit(i, mask);
Forgot to mention, the explicit clearing is for the bits that may be beyond the num_counters. Since we limit it to cci_pmu->num_cntrs here we could get rid of that.
Thanks Suzuki
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