lopper: assists: xlnx_overlay_pl_dt: Validate PL nodes by reg or compatible#773
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zeddii merged 1 commit intoJun 19, 2026
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…atible validate_amba_pl_node() previously required at least one child of /amba_pl to have a 'reg' property before an overlay was generated. Designs whose /amba_pl contains only non-address-mapped nodes, for example the zocl node 'zyxclmm_drm', which has a 'compatible' but no 'reg', failed this check: the assist aborted early, emitted no pl.dtsi, and left /amba_pl in the base device tree, so its nodes were carried into the Linux device tree and the device failed to probe at boot. Treat a node as a valid PL node if it has a 'reg' or a 'compatible' property, so such nodes are carried into the overlay (pl.dtsi) and /amba_pl is removed from the base tree exactly as in the normal flow. Iterate with children_only=True so the /amba_pl bus node's own "simple-bus" compatible is not counted. Signed-off-by: Aravind Thokala <aravind.thokala@amd.com>
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@onkarharsh , please review. |
onkarharsh
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Jun 19, 2026
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Looks good to me. |
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Root Cause:
xlnx_overlay_pl_dt's validate_amba_pl_node() only considered a /amba_pl
child to be a valid PL node if it had a reg property. On designs where
/amba_pl contains only non-address-mapped nodes — e.g. the zocl node
zyxclmm_drm, which has a compatible but no reg — validation failed. As a
result the assist aborted early: it generated no pl.dtsi and, crucially,
did not remove /amba_pl from the base device tree.
Because /amba_pl was left in the base SDT, downstream processing
(gen_domain_dts) carried its nodes into the generated Linux device tree.
The kernel then probed the device even though no PL is present, and the
probe failed at boot.
Fix:
Treat a /amba_pl child as a valid PL node if it has reg or compatible, so
non-address-mapped nodes like zocl are recognized. With validation
passing, the assist now:
no longer leaks into the Linux DT).
The scan uses children_only=True so the /amba_pl bus node's own compatible
= "simple-bus" is not mistakenly counted (otherwise every /amba_pl,
including an empty one, would pass).