a85a6c86c2
These interfaces return a negative error number or an IRQ:
platform_get_irq()
platform_get_irq_optional()
platform_get_irq_byname()
platform_get_irq_byname_optional()
The function comments suggest checking for error like this:
irq = platform_get_irq(...);
if (irq < 0)
return irq;
which is what most callers (~900 of 1400) do, so it's implicit that IRQ 0
is invalid. But some callers check for "irq <= 0", and it's not obvious
from the source that we never return an IRQ 0.
Make this more explicit by updating the comments to say that an IRQ number
is always non-zero and adding a WARN() if we ever do return zero. If we do
return IRQ 0, it likely indicates a bug in the arch-specific parts of
platform_get_irq().
Relevant prior discussion at [1, 2].
[1] https://lore.kernel.org/r/Pine.LNX.4.64.0701250940220.25027@woody.linux-foundation.org/
[2] https://lore.kernel.org/r/Pine.LNX.4.64.0701252029570.25027@woody.linux-foundation.org/
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
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|---|---|---|
| Documentation | ||
| LICENSES | ||
| arch | ||
| block | ||
| certs | ||
| crypto | ||
| drivers | ||
| fs | ||
| include | ||
| init | ||
| ipc | ||
| kernel | ||
| lib | ||
| mm | ||
| net | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .clang-format | ||
| .cocciconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| COPYING | ||
| CREDITS | ||
| Kbuild | ||
| Kconfig | ||
| MAINTAINERS | ||
| Makefile | ||
| README | ||
README
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.