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A mirror of the official Linux kernel repository just in case
80f4e62730
Panfrost DRM driver uses devfreq to perform DVFS, while using simple_ondemand devfreq governor by default. This causes driver initialization to fail on boot when simple_ondemand governor isn't built into the kernel statically, as a result of the missing module dependency and, consequently, the required governor module not being included in the initial ramdisk. Thus, let's mark simple_ondemand governor as a softdep for Panfrost, to have its kernel module included in the initial ramdisk. This is a rather longstanding issue that has forced distributions to build devfreq governors statically into their kernels, [1][2] or has forced users to introduce some unnecessary workarounds. [3] For future reference, not having support for the simple_ondemand governor in the initial ramdisk produces errors in the kernel log similar to these below, which were taken from a Pine64 RockPro64: panfrost ff9a0000.gpu: [drm:panfrost_devfreq_init [panfrost]] *ERROR* Couldn't initialize GPU devfreq panfrost ff9a0000.gpu: Fatal error during GPU init panfrost: probe of ff9a0000.gpu failed with error -22 Having simple_ondemand marked as a softdep for Panfrost may not resolve this issue for all Linux distributions. In particular, it will remain unresolved for the distributions whose utilities for the initial ramdisk generation do not handle the available softdep information [4] properly yet. However, some Linux distributions already handle softdeps properly while generating their initial ramdisks, [5] and this is a prerequisite step in the right direction for the distributions that don't handle them properly yet. [1] https://gitlab.manjaro.org/manjaro-arm/packages/core/linux/-/blob/linux61/config?ref_type=heads#L8180 [2] https://salsa.debian.org/kernel-team/linux/-/merge_requests/1066 [3] https://forum.pine64.org/showthread.php?tid=15458 [4] https://git.kernel.org/pub/scm/utils/kernel/kmod/kmod.git/commit/?id=49d8e0b59052999de577ab732b719cfbeb89504d [5] |
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| certs | ||
| crypto | ||
| Documentation | ||
| drivers | ||
| fs | ||
| include | ||
| init | ||
| io_uring | ||
| ipc | ||
| kernel | ||
| lib | ||
| LICENSES | ||
| mm | ||
| net | ||
| rust | ||
| samples | ||
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| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .clang-format | ||
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| .editorconfig | ||
| .get_maintainer.ignore | ||
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| .mailmap | ||
| .rustfmt.toml | ||
| COPYING | ||
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| Kbuild | ||
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| MAINTAINERS | ||
| Makefile | ||
| 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 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.