Readers looking for user-oriented information may benefit from it.
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Reviewed-by: David Vernet <void@manifault.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Link: https://lore.kernel.org/r/20220927160559.97154-8-corbet@lwn.netSigned-off-by: Jonathan Corbet <corbet@lwn.net>

These files describe part of the core API, but have never been converted to
RST due to ... let's say local oppposition.  So, create a set of
special-purpose wrappers to ..include these files into a separate page so
that they can be a part of the htmldocs build.  Then link them into the
core-api manual and remove them from the "staging" dumping ground.
Acked-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Reviewed-by: David Vernet <void@manifault.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Link: https://lore.kernel.org/r/20220927160559.97154-7-corbet@lwn.netSigned-off-by: Jonathan Corbet <corbet@lwn.net>

This one file should not really be in the top-level documentation
directory.  core-api/ may not be a perfect fit but seems to be best, so
move it there.  Adjust a couple of internal document references to make
them location-independent, and point checkpatch.pl at the new location.

Cc: Jiri Slaby <jirislaby@kernel.org>
Cc: Joe Perches <joe@perches.com>
Reviewed-by: David Vernet <void@manifault.com>
Acked-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Link: https://lore.kernel.org/r/20220927160559.97154-6-corbet@lwn.netSigned-off-by: Jonathan Corbet <corbet@lwn.net>

There is some useless boilerplate text that was added by sphinx when this
file was first created; take it out.
Reviewed-by: David Vernet <void@manifault.com>
Acked-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Link: https://lore.kernel.org/r/20220927160559.97154-5-corbet@lwn.netSigned-off-by: Jonathan Corbet <corbet@lwn.net>

Use the html_sidebars directive to get a more useful set of links in the
left column.

Unfortunately, this is a no-op with the default RTD theme, but others
observe it.
Reviewed-by: David Vernet <void@manifault.com>
Acked-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Link: https://lore.kernel.org/r/20220927160559.97154-4-corbet@lwn.netSigned-off-by: Jonathan Corbet <corbet@lwn.net>

The front page is the entry point to the documentation, especially for
people who read it online.  It's a big mess of everything we could think to
toss into it.  Rewrite the page with an eye toward simplicity and making it
easy for readers to get going toward what they really want to find.

This is only a beginning, but it makes our docs more approachable than
before.
Acked-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: David Vernet <void@manifault.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Link: https://lore.kernel.org/r/20220927160559.97154-3-corbet@lwn.netSigned-off-by: Jonathan Corbet <corbet@lwn.net>

...otherwise Sphinx won't cooperate when trying to list it explicitly in
the top-level index.rst file
Reviewed-by: David Vernet <void@manifault.com>
Acked-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Link: https://lore.kernel.org/r/20220927160559.97154-2-corbet@lwn.netSigned-off-by: Jonathan Corbet <corbet@lwn.net>

Add devm_spi_alloc_master() and devm_spi_alloc_slave() to devres.rst.
They are introduced by
commit 5e844cc3 ("spi: Introduce device-managed SPI controller allocation").
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Reviewed-by: Lukas Wunner <lukas@wunner.de>
Link: https://lore.kernel.org/r/20220923141803.75734-1-yangyingliang@huawei.comSigned-off-by: Jonathan Corbet <corbet@lwn.net>

Add devm_pinctrl_get_select() and devm_pinctrl_register_and_init() to
devres.rst.
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Link: https://lore.kernel.org/r/20220922153737.2863951-1-yangyingliang@huawei.comSigned-off-by: Jonathan Corbet <corbet@lwn.net>

should be kB instead of Kb
Signed-off-by: Hoi Pok Wu <wuhoipok@gmail.com>
Reviewed-by: Muchun Song <songmuchun@bytedance.com>
Link: https://lore.kernel.org/r/20220922030645.9719-1-wuhoipok@gmail.comSigned-off-by: Jonathan Corbet <corbet@lwn.net>

The last English version used:
  commit 2f51efc6 ("docs: bootconfig: Add how to embed the
  bootconfig into kernel")
Signed-off-by: Wu XiangCheng <bobwxc@email.cn>
Reviewed-by: Yanteng Si <siyanteng@loongson.cn>
Link: https://lore.kernel.org/r/386249dc333a3e40b80c3a9483d60d2bfd24a6c4.1663850554.git.bobwxc@email.cnSigned-off-by: Jonathan Corbet <corbet@lwn.net>

* update to commit ea052e7257bd ("docs: admin-guide: for kernel bugs
  refer to other kernel documentation")

We are in 6.x now ;)
Signed-off-by: Wu XiangCheng <bobwxc@email.cn>
Reviewed-by: Yanteng Si <siyanteng@loongson.cn>
Link: https://lore.kernel.org/r/7f6e0b8961f79befa62e0070f9682ab3abde8622.1663850554.git.bobwxc@email.cnSigned-off-by: Jonathan Corbet <corbet@lwn.net>

Translate core-api/packing.rst into Chinese.

Last English version used:

commit 1ec779b9 ("docs: packing: move it to core-api book
and adjust markups").
Signed-off-by: Binbin Zhou <zhoubinbin@loongson.cn>
Reviewed-by: Wu XiangCheng <bobwxc@email.cn>
Reviewed-by: Yanteng Si<siyanteng@loongson.cn>
Reviewed-by: Alex Shi <alexs@kernel.org>
Link: https://lore.kernel.org/r/96b19575ca7e9e23941e8a5ef92120f1bffbc518.1660881950.git.zhoubinbin@loongson.cnSigned-off-by: Jonathan Corbet <corbet@lwn.net>

Translate core-api/generic-radix-tree.rst into Chinese.

Last English version used:

commit ba20ba2e ("generic radix trees").
Signed-off-by: Binbin Zhou <zhoubinbin@loongson.cn>
Reviewed-by: Wu XiangCheng <bobwxc@email.cn>
Reviewed-by: Yanteng Si<siyanteng@loongson.cn>
Reviewed-by: Alex Shi <alexs@kernel.org>
Link: https://lore.kernel.org/r/aad94e2a053ae021eb4d63240690b05c2f3e8dec.1660881950.git.zhoubinbin@loongson.cnSigned-off-by: Jonathan Corbet <corbet@lwn.net>

Translate core-api/circular-buffers.rst into Chinese.

Last English version used:

commit 714b6904 ("doc: Remove ".vnet" from paulmck email addresses").
Signed-off-by: Binbin Zhou <zhoubinbin@loongson.cn>
Reviewed-by: Wu XiangCheng <bobwxc@email.cn>
Reviewed-by: Yanteng Si<siyanteng@loongson.cn>
Link: https://lore.kernel.org/r/6b94f233dd4b4a9e6da6fa2f86a9b1d32f104004.1660881950.git.zhoubinbin@loongson.cnSigned-off-by: Jonathan Corbet <corbet@lwn.net>

Translate core-api/idr.rst into Chinese.

Last English version used:

commit 85656ec1 ("IDR: Note that the IDR API is deprecated").
Signed-off-by: Binbin Zhou <zhoubinbin@loongson.cn>
Reviewed-by: Wu XiangCheng <bobwxc@email.cn>
Reviewed-by: Yanteng Si<siyanteng@loongson.cn>
Reviewed-by: Alex Shi <alexs@kernel.org>
Link: https://lore.kernel.org/r/9f578ea087df7ef8665fc08541d208e7429176ec.1660881950.git.zhoubinbin@loongson.cnSigned-off-by: Jonathan Corbet <corbet@lwn.net>

do_IRQ has been replaced by common_interrupt in commit
fa5e5c40 ("x86/entry: Use idtentry for interrupts").
Signed-off-by: Tuo Cao <91tuocao@gmail.com>
Link: https://lore.kernel.org/r/20220915150155.9908-1-91tuocao@gmail.comSigned-off-by: Jonathan Corbet <corbet@lwn.net>

Fix grammar and improve readability of chipidea-usb2 text.
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Peter Chen <peter.chen@kernel.org>
Cc: linux-usb@vger.kernel.org
Acked-by: Peter Chen <peter.chen@kernel.org>
Link: https://lore.kernel.org/r/20220827203217.7837-1-rdunlap@infradead.orgSigned-off-by: Jonathan Corbet <corbet@lwn.net>

Correct one typo/spello and remove one duplicated word in the
W1 documentation.
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: linux-doc@vger.kernel.org
Cc: Evgeniy Polyakov <zbr@ioremap.net>
Link: https://lore.kernel.org/r/20220828002845.7022-1-rdunlap@infradead.orgSigned-off-by: Jonathan Corbet <corbet@lwn.net>

Clean up punctuation, spelling, and formatting for command line usage
and modprobe config file usage in udlfb.rst.
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Bernie Thompson <bernie@plugable.com>
Cc: linux-fbdev@vger.kernel.org
Cc: dri-devel@lists.freedesktop.org
Cc: Helge Deller <deller@gmx.de>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: linux-doc@vger.kernel.org
Cc: Bagas Sanjaya <bagasdotme@gmail.com>
Link: https://lore.kernel.org/r/20220828192501.14232-1-rdunlap@infradead.orgSigned-off-by: Jonathan Corbet <corbet@lwn.net>

In Fedora 36, cross-compiling an allmodconfig configuration
for other architectures on x86 fails with this problem:

In file included from ../scripts/gcc-plugins/gcc-common.h:95,
                 from ../scripts/gcc-plugins/latent_entropy_plugin.c:78:
/usr/lib/gcc/aarch64-linux-gnu/12/plugin/include/builtins.h:23:10: fatal
error: mpc.h: No such file or directory
   23 | #include <mpc.h>
      |          ^~~~~~~
compilation terminated.

In that distro, that header file is available in the separate
libmpc-devel package.

Although future versions of Fedora might correctly mark
that dependency, mention this additional package.

To help detect such problems ahead of time, describe the
    gcc -print-file-name=plugin
command that is used by scripts/gcc-plugins/Kconfig to detect
plugins [1].

[1] https://lore.kernel.org/lkml/CAHk-=wjjiYjCp61gdAMpDOsUBU-A2hFFKJoVx5VAC7yV4K6WYg@xxxxxxxxxxxxxx/

Fixes: 43e96ef8 ("docs/core-api: Add Fedora instructions for GCC plugins");
Signed-off-by: Robert Elliott <elliott@hpe.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20220827193836.2582079-1-elliott@hpe.comSigned-off-by: Jonathan Corbet <corbet@lwn.net>

Fix a typo of "or" which should be "of".
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Jeremy Kerr <jk@ozlabs.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: linuxppc-dev@lists.ozlabs.org
Cc: Jonathan Corbet <corbet@lwn.net>
Reviewed-by: Jeremy Kerr <jk@ozlabs.org>
Link: https://lore.kernel.org/r/20220829232908.32437-1-rdunlap@infradead.orgSigned-off-by: Jonathan Corbet <corbet@lwn.net>

* update to commit c04639a7 ("coding-style.rst: trivial: fix
  location of driver model macros")
Signed-off-by: Wu XiangCheng <bobwxc@email.cn>
Reviewed-by: Yanteng Si <siyanteng@loongson.cn>
Reviewed-by: Alex Shi <alexs@kernel.org>
Link: https://lore.kernel.org/r/Yw2ewM4wfaDDLjTk@bobwxc.mipcSigned-off-by: Jonathan Corbet <corbet@lwn.net>

commit 7c693f54 ("x86/speculation: Add spectre_v2=ibrs option to support Kernel IBRS")

adds the "ibrs " option  in
Documentation/admin-guide/kernel-parameters.txt but omits it to
Documentation/admin-guide/hw-vuln/spectre.rst, add it.
Signed-off-by: Lin Yujun <linyujun809@huawei.com>
Link: https://lore.kernel.org/r/20220830123614.23007-1-linyujun809@huawei.comSigned-off-by: Jonathan Corbet <corbet@lwn.net>

Change occurrences of "it's" that are possessive to "its"
so that they don't read as "it is".

For f2fs.rst, reword one description for better clarity.
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: linux-fsdevel@vger.kernel.org
Cc: linux-f2fs-devel@lists.sourceforge.net
Cc: linux-xfs@vger.kernel.org
Cc: Christian Brauner <brauner@kernel.org>
Cc: Seth Forshee <sforshee@kernel.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Jaegeuk Kim <jaegeuk@kernel.org>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: "Christian Brauner (Microsoft)" <brauner@kernel.org>
Reviewed-by: Chao Yu <chao@kernel.org>
Reviewed-by: Jaegeuk Kim <jaegeuk@kernel.org>
Link: https://lore.kernel.org/r/20220901002828.25102-1-rdunlap@infradead.orgSigned-off-by: Jonathan Corbet <corbet@lwn.net>

Additionally to the "commit <sha1> upstream." variant, "[ Upstream
commit <sha1> ]" is used as well as alternative to refer to the upstream
commit hash.
Signed-off-by: Salvatore Bonaccorso <carnil@debian.org>
Link: https://lore.kernel.org/r/20220901184328.4075701-1-carnil@debian.orgSigned-off-by: Jonathan Corbet <corbet@lwn.net>

Update mediator information in the CoC interpretation document.
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
Link: https://lore.kernel.org/r/20220901212319.56644-1-skhan@linuxfoundation.org
Cc: stable@vger.kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

Translte .../devicetree/kernel-api.rst into Chinese.
Signed-off-by: Yanteng Si <siyanteng@loongson.cn>
Reviewed-by: Alex Shi <alexs@kernel.org>
Link: https://lore.kernel.org/r/35fd1b5801d7191e078937908008115f8949aac3.1662449105.git.siyanteng@loongson.cnSigned-off-by: Jonathan Corbet <corbet@lwn.net>

Translate .../devicetree/overlay-notes.rst into Chinese.
Signed-off-by: Yanteng Si <siyanteng@loongson.cn>
Reviewed-by: Alex Shi <alexs@kernel.org>
Link: https://lore.kernel.org/r/b957580e448e2d0ab7917644c8f8f1614060b20a.1662449105.git.siyanteng@loongson.cnSigned-off-by: Jonathan Corbet <corbet@lwn.net>

Translate .../devicetree/dynamic-resolution-notes.rst into Chinese.
Signed-off-by: Yanteng Si <siyanteng@loongson.cn>
Reviewed-by: Alex Shi <alexs@kernel.org>
Link: https://lore.kernel.org/r/d8b7c06fe8fdb58cb2ec6989e09f9999aca2d8d1.1662449105.git.siyanteng@loongson.cnSigned-off-by: Jonathan Corbet <corbet@lwn.net>

Translate .../devicetree/changesets.rst into Chinese.
Signed-off-by: Yanteng Si <siyanteng@loongson.cn>
Reviewed-by: Alex Shi <alexs@kernel.org>
Link: https://lore.kernel.org/r/07d23cedda1e2cd8cf40d68059024d116f8d004e.1662449105.git.siyanteng@loongson.cnSigned-off-by: Jonathan Corbet <corbet@lwn.net>

Translate .../PCI/acpi-info.rst into Chinese.
Add PCI into .../zh_CN/index.rst.
Signed-off-by: Yanteng Si <siyanteng@loongson.cn>
Reviewed-by: Alex Shi <alexs@kernel.org>
Reviewed-by: Wu XiangCheng <bobwxc@email.cn>
Link: https://lore.kernel.org/r/f07ba17ae9c6d728d6135ecc0577a932e9836fba.1662449105.git.siyanteng@loongson.cnSigned-off-by: Jonathan Corbet <corbet@lwn.net>

Fix spelling mistakes, "mesages" should be spelled "messages".
Signed-off-by: Rong Tao <rtoax@foxmail.com>
Link: https://lore.kernel.org/r/tencent_924BF0B25425E2D5673409D1CF604F682505@qq.comSigned-off-by: Jonathan Corbet <corbet@lwn.net>

I have deleted duplicate words like

to, guest, trace, when, we
Signed-off-by: Akhil Raj <lf32.dev@gmail.com>
Link: https://lore.kernel.org/r/20220829065239.4531-1-lf32.dev@gmail.comSigned-off-by: Jonathan Corbet <corbet@lwn.net>

The current section 'If something goes wrong' makes a number of suggestions
for debugging, bug hunting and reporting issues, which are quite briefly
described in that section.

However, the suggestions are also well covered in other kernel
documentation or sometimes simply outdated. Here, each suggestion in that
section is summarized, and then followed with its assessment, and the
derived action for each suggestion:

  - use MAINTAINERS and mailing list: covered in 'Reporting issues',
    summarized in the short guide, detailed in its further section.
    Reporting issues even provides some specific examples that guides
    readers well through the needed steps. Refer to 'Reporting issues'.

  - contact Linus Torvalds: probably outdated as currently described.
    nevertheless covered in 'Reporting issues'. Reporting issues points out
    to contact the relevant kernel maintainers first, and after some
    patience and failed attempts with those maintainers, contacting Linus
    Torvalds might be okay. Refer to 'Reporting issues'.

  - tell what kernel, how to duplicate, the setup, if the problem is new
    or old and when did you notice: covered in 'Reporting issues',
    especially in Step-by-step guide how to report issues to the kernel
    maintainers. Refer to 'Reporting issues'.

  - duplicate kernel bug reports exactly: covered in 'Reporting issues',
    especially in Write and send the report. Refer to 'Reporting issues'.

  - read 'Bug hunting': keep this reference. Refer to 'Bug hunting'.

  - compile the kernel with CONFIG_KALLSYMS: covered in 'Reporting issues',
    especially in Decode failure messages. Refer to 'Reporting issues'.

  - alternatively, use ksymoops: ksymoops at the mentioned URL seems not to
    be maintained anymore. It was released roughly once a year until
    version 2.4.11 in 2005, but has not seen a new release since then. The
    information in ./scripts/ksymoops/README is from 1999, and does not
    give more insight on its actual maintenance state either. Ksymoops is
    mentioned as system utility in changes.rst, but also not recommended
    there. Drop the explanation on using ksymoops.

  - alternatively, lookup dump manually with the EIP and nm to determine
    the function in which the kernel crashes: this method seems already a
    quite advanced and low-level debugging method. Even all the further
    references on bug hunting and debugging do not mention it. Drop this
    alternative method and limit mentioning methods explained in the other
    existing kernel documentation.

  - read 'Reporting issues': keep this reference.
    Refer to 'Reporting issues'.

  - use gdb for debugging: some specific details, e.g., edit
    arch/x86/Makefile, are probably outdated or limited to one (historic
    important) setup. Using gdb is covered in 'Bug hunting', 'Debugging
    kernel and modules via gdb' and 'Using kgdb, kdb and the kernel
    debugger internals'. Refer to those three documents.

Overall, it is sufficient to refer to reporting-issues.rst,
bug-hunting.rst, gdb-kernel-debugging.rst and kgdb.rst and this way cover
the existing suggestions.

'Reporting issues' is quite new and probably up to date. 'Bug hunting',
'Debugging kernel and modules via gdb' and 'Using kgdb, kdb and the kernel
debugger internals' might need some revisit and update, but they are
generally in an acceptable state for referring to them.

Replace the existing suggestions by reference to other existing kernel
documentation covering those suggestions---partly even nicely summarized
and then explained in greater detail.
Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Link: https://lore.kernel.org/r/20220720041325.15693-3-lukas.bulwahn@gmail.comSigned-off-by: Jonathan Corbet <corbet@lwn.net>

Running a.out user programs with the latest kernel release is a very rare
and uncommon use case nowadays. The support of a.out user programs is only
remaining for the alpha architecture and is not defined and activated in
the architecture's Kconfig (so even the activation of this support requires
to modify the Kconfig file and not just kernel build configuration).

The discussion on a.out support in 2019 (see Link) shows that the support
of a.out user programs is just remaining for a special corner case from
some (alpha architecture) users.

There is no need to point out and mention this special feature to the
general audience of kernel users. Delete the reference to this historic and
special feature.

Link: https://lore.kernel.org/all/CAHk-=wgt7M6yA5BJCJo0nF22WgPJnN8CvViL9CAJmd+S+Civ6w@mail.gmail.com/Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Link: https://lore.kernel.org/r/20220720041325.15693-2-lukas.bulwahn@gmail.comSigned-off-by: Jonathan Corbet <corbet@lwn.net>

Correct all uses of "it's" that are meant to be possessive "its".
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/20220801025207.29971-1-rdunlap@infradead.orgSigned-off-by: Jonathan Corbet <corbet@lwn.net>

I have removed repeated `the` inside the documentation
Signed-off-by: Akhil Raj <lf32.dev@gmail.com>
Link: https://lore.kernel.org/r/20220827145359.32599-1-lf32.dev@gmail.comSigned-off-by: Jonathan Corbet <corbet@lwn.net>

On some distros with coarse-grained packaging policy, dvipng is
installed along with latex.  In such cases, math rendering will
use imgmath by default.  It is possible to override the choice by
specifying the option string of "-D html_math_renderer='mathjax'"
to sphinx-build (Sphinx >= 1.8).

To provide developers an easier-to-use knob, add code for an env
variable "SPHINX_IMGMATH" which overrides the automatic choice
of math renderer for html docs.

    SPHINX_IMGMATH=yes : Load imgmath even if dvipng is not found
    SPHINX_IMGMATH=no  : Don't load imgmath (fall back to mathjax)
Signed-off-by: Akira Yokosawa <akiyks@gmail.com>
Acked-by: Mauro Carvalho Chehab <mchehab@kernel.org>
Link: https://lore.kernel.org/r/5a582b2b-d51c-a062-36b2-19479cf68fab@gmail.comSigned-off-by: Jonathan Corbet <corbet@lwn.net>

Currently, math expressions using the "math::" directive or
the ":math:" role of Sphinx need the imgmath extension for proper
rendering in html and epub builds.
imgmath requires dvipng (and latex).
Otherwise, "make htmldocs" will complain of missing commands.

As a matter of fact, the mathjax extension is loaded by default since
Sphinx v1.8 and it is good enough for html docs without any dependency
on texlive packages.

Stop loading the imgmath extension for html docs unless requirements
for imgmath are met.

To find out whether required commands are available, add a helper
find_command(), which is a wrapper of shutil.which().

For epub docs, keep the same behavior of always loading imgmath.
Signed-off-by: Akira Yokosawa <akiyks@gmail.com>
Acked-by: Mauro Carvalho Chehab <mchehab@kernel.org>
Link: https://lore.kernel.org/r/a6a877fc-dc93-2bda-a6d3-37001d99942a@gmail.com
[jc: Took out the writing of the math_renderer decision]
Signed-off-by: Jonathan Corbet <corbet@lwn.net>