Re: [PATCH v2] coresight: trbe: Hide enable_sink sysfs file

[James Clark]

On 11/08/2026 10:04, Leo Yan wrote:
> On Fri, Aug 07, 2026 at 11:13:22AM +0100, James Clark wrote:
> > TRBE doesn't support sysfs mode, but the enable_sink file can still be
> > successfully written to enable the device, and only attempting to enable
> > the source would later fail.
> >
> > Avoid misleading users by adding a flag that devices can use to hide
> > either the enable_sink or enable_source files, and set it for TRBE.
> >
> > Don't set it for ETE as it's possible that ETE could appear on the
> > legacy bus and work with sysfs, and writing to enable_source already
> > reports EINVAL if the device doesn't support sysfs mode.
>
> It is a pity that we cannot determine from the ETE registers whether ETE
> is connected to the legacy bus or TRBE.

We could determine it from the device tree. A path has to be built or 
you can't use it on the legacy bus either. Maybe we can do a more 
general change in the future to hide the flag for any non-connected CPU 
source.

> > Signed-off-by: James Clark <james.clark@xxxxxxxxxx>
>
> Reviewed-by: Leo Yan <leo.yan@xxxxxxx>