cxl/hdm: Restore commit_end when decoder enumeration fails

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 uncommitted 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")
Reviewed-by: Jonathan Cameron <jonathan.cameron@oss.qualcomm.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Reviewed-by: Li Ming <ming.li@zohomail.com>
Reviewed-by: Richard Cheng <icheng@nvidia.com>
Signed-off-by: Alison Schofield <alison.schofield@intel.com>
Link: https://patch.msgid.link/4802c5abc906b858a4754bfc4fa3e4c2c455d0c3.1786143520.git.alison.schofield@intel.com
Signed-off-by: Dave Jiang <dave.jiang@intel.com>

0 files changed, 0 insertions, 0 deletions