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commit7f00be96f1("of: property: Add device link support for interrupt-parent, dmas and -gpio(s)") started adding device links for the interrupt-parent property. commit4104ca776b("of: property: Add fw_devlink support for interrupts") and commitf265f06af1("of: property: Fix fw_devlink handling of interrupts/interrupts-extended") later added full support for parsing the interrupts and interrupts-extended properties, which includes looking up the node of the parent domain. This made the handler for the interrupt-parent property redundant. In fact, creating device links based solely on interrupt-parent is problematic, because it can create spurious cycles. A node may have this property without itself being an interrupt controller or consumer. For example, this property is often present in the root node or a /soc bus node to set the default interrupt parent for child nodes. However, it is incorrect for the bus to depend on the interrupt controller, as some of the bus's children may not be interrupt consumers at all or may have a different interrupt parent. Resolving these spurious dependency cycles can cause an incorrect probe order for interrupt controller drivers. This was observed on a RISC-V system with both an APLIC and IMSIC under /soc, where interrupt-parent in /soc points to the APLIC, and the APLIC msi-parent points to the IMSIC. fw_devlink found three dependency cycles and attempted to probe the APLIC before the IMSIC. After applying this patch, there were no dependency cycles and the probe order was correct. Acked-by: Marc Zyngier <maz@kernel.org> Cc: stable@vger.kernel.org Fixes:4104ca776b("of: property: Add fw_devlink support for interrupts") Signed-off-by: Samuel Holland <samuel.holland@sifive.com> Link: https://lore.kernel.org/r/20241120233124.3649382-1-samuel.holland@sifive.com Signed-off-by: Rob Herring (Arm) <robh@kernel.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the reStructuredText markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.