Re: [PATCH] coresight: tpdm: fix invalid MMIO access issue

From: Leo Yan

Date: Tue Apr 07 2026 - 06:37:40 EST


Hi Jie,

On Tue, Apr 07, 2026 at 04:33:22PM +0800, Jie Gan wrote:
> On 4/7/2026 4:10 PM, Leo Yan wrote:
> > On Tue, Apr 07, 2026 at 12:47:11PM +0800, Jie Gan wrote:
> > > Create the csdev_access struct only when a valid MMIO resource is
> > > available. In tpdm_probe(), base is uninitialized for static TPDM
> > > instances that lack an MMIO resource, causing csdev_access to be
> > > created with a garbage address and potentially leading to
> > > unexpected issues.
> >
> > This patch itself is fine for me. However, I am wandering if this
> > is sufficient.
> >
> > As mentioned "potentially leading to unexpected issues", can I
> > understand some code pieces access register with uninitialized base?
> > If so, you would also explictly add coresight_is_static_tpdm() to
> > prevent register access.
> >
>
> Actually, we havent MMIO access for the static TPDM device, So no issues are
> observed. The commit message here may be misleading. do I need rephrase the
> commit message?

Yes, good to clarify a bit in commit log:

"So far there has no register access for static instance, but this
change helps mitigate potential risks in the future."

With this:

Reviewed-by: Leo Yan <leo.yan@xxxxxxx>