Messages in this thread | | | Subject | Re: [PATCH V3 13/18] coresight: tmc: make sysFS and Perf mode mutually exclusive | From | Suzuki K Poulose <> | Date | Mon, 25 Apr 2016 15:52:06 +0100 |
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On 25/04/16 15:48, Mathieu Poirier wrote: > On 25 April 2016 at 08:32, Suzuki K Poulose <Suzuki.Poulose@arm.com> wrote: >> On 22/04/16 18:14, Mathieu Poirier wrote:
>>> + spin_lock_irqsave(&drvdata->spinlock, flags); >>> + if (drvdata->reading) { >>> + ret = -EINVAL; >>> + goto out; >>> + } >>> + >>> + val = local_xchg(&drvdata->mode, mode); >>> + /* >>> + * In Perf mode there can be only one writer per sink. There >>> + * is also no need to continue if the ETR is already operated >>> + * from sysFS. >>> + */ >>> + if (val != CS_MODE_DISABLED) { >> >> >> Could val be CS_MODE_PERF ? In other words, should we be checking : >> if (val == CS_MODE_SYSFS) instead ? > > If we check for CS_MODE_SYSFS we also have to check for CS_MODE_PERF, > which is two checks rather than a single one with the current > solution.
I am confused now. The comment says, we want to check for sysfs mode and don't continue in that case. So, we shouldn't be worried about PERF mode.
Suzuki
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