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| author | Dan Williams <dan.j.williams@intel.com> | 2023-04-04 00:39:16 +0300 |
|---|---|---|
| committer | Dan Williams <dan.j.williams@intel.com> | 2023-04-05 01:34:34 +0300 |
| commit | d35b495ddf92c964eedf2ac86fdbf88dc3e5cbc9 (patch) | |
| tree | dbf65694296ba30d731a8ce828199fefc64bcbce /drivers/cxl/port.c | |
| parent | b70c2cf95ee1ca2806cb7191504920f8f5b4454e (diff) | |
| download | linux-d35b495ddf92c964eedf2ac86fdbf88dc3e5cbc9.tar.xz | |
cxl/port: Fix find_cxl_root() for RCDs and simplify it
The find_cxl_root() helper is used to lookup root decoders and other CXL
platform topology information for a given endpoint. It turns out that
for RCDs it has never worked. The result of find_cxl_root(&cxlmd->dev)
is always NULL for the RCH topology case because it expects to find a
cxl_port at the host-bridge. RCH topologies only have the root cxl_port
object with the host-bridge as a dport. While there are no reports of
this being a problem to date, by inspection region enumeration should
crash as a result of this problem, and it does in a local unit test for
this scenario.
However, an observation that ever since:
commit f17b558d6663 ("cxl/pmem: Refactor nvdimm device registration, delete the workqueue")
...all callers of find_cxl_root() occur after the memdev connection to
the port topology has been established. That means that find_cxl_root()
can be simplified to a walk of the endpoint port topology to the root.
Switch to that arrangement which also fixes the RCD bug.
Fixes: a32320b71f08 ("cxl/region: Add region autodiscovery")
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/168002857715.50647.344876437247313909.stgit@dwillia2-xfh.jf.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Diffstat (limited to 'drivers/cxl/port.c')
| -rw-r--r-- | drivers/cxl/port.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/cxl/port.c b/drivers/cxl/port.c index 9c8f46ed336b..22a7ab2bae7c 100644 --- a/drivers/cxl/port.c +++ b/drivers/cxl/port.c @@ -119,7 +119,7 @@ static int cxl_endpoint_port_probe(struct cxl_port *port) * This can't fail in practice as CXL root exit unregisters all * descendant ports and that in turn synchronizes with cxl_port_probe() */ - root = find_cxl_root(&cxlmd->dev); + root = find_cxl_root(port); /* * Now that all endpoint decoders are successfully enumerated, try to |