8ff443cebf
If we accidentally unmask IRQs before we've registered a root IRQ handler, handle_arch_irq will be NULL, and the IRQ exception handler will branch to a bogus address. To make this easier to debug, this patch initialises handle_arch_irq to a default handler which will panic(), making such problems easier to debug. When we add support for FIQ handlers, we can follow the same approach. When we add support for a root FIQ handler, it's possible to have root IRQ handler without an root FIQ handler, and in theory the inverse is also possible. To permit this, and to keep the IRQ/FIQ registration logic similar, this patch removes the panic in the absence of a root IRQ controller. Instead, set_handle_irq() logs when a handler is registered, which is sufficient for debug purposes. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Tested-by: Hector Martin <marcan@marcan.st> Cc: James Morse <james.morse@arm.com> Cc: Marc Zyngier <maz@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Will Deacon <will@kernel.org> Acked-by: Will Deacon <will@kernel.org> Link: https://lore.kernel.org/r/20210315115629.57191-4-mark.rutland@arm.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
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 Restructured Text 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.