[PATCH] cxl/region: Add decoder check to check_commit_order()

[Dave Jiang <dave.jiang@intel.com>]

check_commit_order() attempts to convert a device to a decoder without
making sure the device is a decoder. So far this has been working due
to pure luck. Issue discovered while doing deferred dport probing when
child ports are now in the midst of decoders due to ordering change
of child port additions. Add a check before attempting to do decoder
conversion.

Fixes: 105b6235ad0f ("cxl/port: Prevent out-of-order decoder allocation")
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
---
 drivers/cxl/core/region.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c
index c3f4dc244df7..a91d4eb061e4 100644
--- a/drivers/cxl/core/region.c
+++ b/drivers/cxl/core/region.c
@@ -788,7 +788,12 @@ static size_t show_targetN(struct cxl_region *cxlr, char *buf, int pos)
 
 static int check_commit_order(struct device *dev, void *data)
 {
-	struct cxl_decoder *cxld = to_cxl_decoder(dev);
+	struct cxl_decoder *cxld;
+
+	if (!is_switch_decoder(dev))
+		return 0;
+
+	cxld = to_cxl_decoder(dev);
 
 	/*
 	 * if port->commit_end is not the only free decoder, then out of
-- 
2.49.0