Re: [PATCH v4 4/4] cxl/hdm: Restore commit_end when decoder enumeration fails

On Mon, 20 Jul 2026 18:59:40 -0700
Alison Schofield <[email protected]> wrote:

> commit_end tracks the highest committed decoder on a port. It gets
> advanced before decoder enumeration is complete, so a later failure
> leaves it pointing at a decoder that was never added. The next probe
> then rejects decoder0 as out of order and enumeration fails.
> 
> Reset commit_end to the none committed baseline once the decoders are
> torn down, so a subsequent probe rebuilds it from scratch. Register
> the reset before the decoders are added so that on unwind it runs
> after every decoder has been unregistered. This prevents commit_end
> from dropping below the highest committed decoder still registered and
> exposing an inconsistent value to a concurrent reader.
> 
> Protect the commit_end advance in the DVSEC emulation path against
> concurrent readers, matching the register-programmed path.
> 
> Fixes: 176baefb2eb5 ("cxl/hdm: Commit decoder state to hardware")
> Fixes: b777e9bec960 ("cxl/hdm: Emulate HDM decoder from DVSEC range registers")
> Signed-off-by: Alison Schofield <[email protected]>
Reviewed-by: Jonathan Cameron <[email protected]>