Re: [PATCH v3 0/9] coresight: change some driver' spinlock type to raw_spinlock_t

[Suzuki K Poulose]

On 20/12/2024 10:38, Yeoreum Yun wrote:
> Hi Mike.
>
> > Notably missing is the same changes for the etm3x driver. The ETMv3.x
> > and PTM1.x are supported by this driver, and these trace source
> > variants are also supported in perf in the cs_etm.c code.
>
> But I wonder etmv3 needs to change. Because its spinlock is used only
> via sysfs enable/disable path.
> So, I think it doesn't need to change the lock type.

ETM3 can be used in perf mode, similar to the ETM4x.

So, you need to fix it as well.


> > STM is also missing, though this is not directly enabled via perf -
> > but could perhaps run concurrently as it can be a target output for
> > ftrace.
>
> Actually, I couldn't find out the path where
> the STM's lock could be grabbed under other raw_spin_lock (including csdev)
> If you don't mind would you let me the code path please?

STM can't be used in perf mode, and as such you may skip it.

Suzuki


> Thanks
> > --
> > Mike Leach
> > Principal Engineer, ARM Ltd.
> > Manchester Design Centre. UK