Linux kernel ============ The Linux kernel is the core of any Linux operating system. It manages hardware, system resources, and provides the fundamental services for all other software. Quick Start ----------- * Report a bug: See Documentation/admin-guide/reporting-issues.rst * Get the latest kernel: https://kernel.org * Build the kernel: See Documentation/admin-guide/quickly-build-trimmed-linux.rst * Join the community: https://lore.kernel.org/ Essential Documentation ----------------------- All users should be familiar with: * Building requirements: Documentation/process/changes.rst * Code of Conduct: Documentation/process/code-of-conduct.rst * License: See COPYING Documentation can be built with make htmldocs or viewed online at: https://www.kernel.org/doc/html/latest/ Who Are You? ============ Find your role below: * New Kernel Developer - Getting started with kernel development * Academic Researcher - Studying kernel internals and architecture * Security Expert - Hardening and vulnerability analysis * Backport/Maintenance Engineer - Maintaining stable kernels * System Administrator - Configuring and troubleshooting * Maintainer - Leading subsystems and reviewing patches * Hardware Vendor - Writing drivers for new hardware * Distribution Maintainer - Packaging kernels for distros * AI Coding Assistant - LLMs and AI-powered development tools For Specific Users ================== New Kernel Developer -------------------- Welcome! Start your kernel development journey here: * Getting Started: Documentation/process/development-process.rst * Your First Patch: Documentation/process/submitting-patches.rst * Coding Style: Documentation/process/coding-style.rst * Build System: Documentation/kbuild/index.rst * Development Tools: Documentation/dev-tools/index.rst * Kernel Hacking Guide: Documentation/kernel-hacking/hacking.rst * Core APIs: Documentation/core-api/index.rst Academic Researcher ------------------- Explore the kernel's architecture and internals: * Researcher Guidelines: Documentation/process/researcher-guidelines.rst * Memory Management: Documentation/mm/index.rst * Scheduler: Documentation/scheduler/index.rst * Networking Stack: Documentation/networking/index.rst * Filesystems: Documentation/filesystems/index.rst * RCU (Read-Copy Update): Documentation/RCU/index.rst * Locking Primitives: Documentation/locking/index.rst * Power Management: Documentation/power/index.rst Security Expert --------------- Security documentation and hardening guides: * Security Documentation: Documentation/security/index.rst * LSM Development: Documentation/security/lsm-development.rst * Self Protection: Documentation/security/self-protection.rst * Reporting Vulnerabilities: Documentation/process/security-bugs.rst * CVE Procedures: Documentation/process/cve.rst * Embargoed Hardware Issues: Documentation/process/embargoed-hardware-issues.rst * Security Features: Documentation/userspace-api/seccomp_filter.rst Backport/Maintenance Engineer ----------------------------- Maintain and stabilize kernel versions: * Stable Kernel Rules: Documentation/process/stable-kernel-rules.rst * Backporting Guide: Documentation/process/backporting.rst * Applying Patches: Documentation/process/applying-patches.rst * Subsystem Profile: Documentation/maintainer/maintainer-entry-profile.rst * Git for Maintainers: Documentation/maintainer/configure-git.rst System Administrator -------------------- Configure, tune, and troubleshoot Linux systems: * Admin Guide: Documentation/admin-guide/index.rst * Kernel Parameters: Documentation/admin-guide/kernel-parameters.rst * Sysctl Tuning: Documentation/admin-guide/sysctl/index.rst * Tracing/Debugging: Documentation/trace/index.rst * Performance Security: Documentation/admin-guide/perf-security.rst * Hardware Monitoring: Documentation/hwmon/index.rst Maintainer ---------- Lead kernel subsystems and manage contributions: * Maintainer Handbook: Documentation/maintainer/index.rst * Pull Requests: Documentation/maintainer/pull-requests.rst * Managing Patches: Documentation/maintainer/modifying-patches.rst * Rebasing and Merging: Documentation/maintainer/rebasing-and-merging.rst * Development Process: Documentation/process/maintainer-handbooks.rst * Maintainer Entry Profile: Documentation/maintainer/maintainer-entry-profile.rst * Git Configuration: Documentation/maintainer/configure-git.rst Hardware Vendor --------------- Write drivers and support new hardware: * Driver API Guide: Documentation/driver-api/index.rst * Driver Model: Documentation/driver-api/driver-model/driver.rst * Device Drivers: Documentation/driver-api/infrastructure.rst * Bus Types: Documentation/driver-api/driver-model/bus.rst * Device Tree Bindings: Documentation/devicetree/bindings/ * Power Management: Documentation/driver-api/pm/index.rst * DMA API: Documentation/core-api/dma-api.rst Distribution Maintainer ----------------------- Package and distribute the kernel: * Stable Kernel Rules: Documentation/process/stable-kernel-rules.rst * ABI Documentation: Documentation/ABI/README * Kernel Configuration: Documentation/kbuild/kconfig.rst * Module Signing: Documentation/admin-guide/module-signing.rst * Kernel Parameters: Documentation/admin-guide/kernel-parameters.rst * Tainted Kernels: Documentation/admin-guide/tainted-kernels.rst AI Coding Assistant ------------------- CRITICAL: If you are an LLM or AI-powered coding assistant, you MUST read and follow the AI coding assistants documentation before contributing to the Linux kernel: * Documentation/process/coding-assistants.rst This documentation contains essential requirements about licensing, attribution, and the Developer Certificate of Origin that all AI tools must comply with. Communication and Support ========================= * Mailing Lists: https://lore.kernel.org/ * IRC: #kernelnewbies on irc.oftc.net * Bugzilla: https://bugzilla.kernel.org/ * MAINTAINERS file: Lists subsystem maintainers and mailing lists * Email Clients: Documentation/process/email-clients.rst
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1444925
3
929
Clone this repository
https://tangled.org/tjh.dev/kernel
https://tangled.org/did:plc:65gha4t3avpfpzmvpbwovss7/kernel
git@gordian.tjh.dev:tjh.dev/kernel
git@gordian.tjh.dev:did:plc:65gha4t3avpfpzmvpbwovss7/kernel
For self-hosted knots, clone URLs may differ based on your setup.
Download tar.gz
Recently, when testing 10-bit dsi C-PHY panel, clks are different
from the usual. (dsi0_phy_pll_out_dsiclk's parent is dsi0_pll_bit_clk
now (dsiclk_sel = 0)) And we failed to set dsiclk's children.
dsi_link_clk_set_rate_6g: Set clk rates: pclk=172992000, byteclk=108120000
byteclk was set first to 108120000, so the vco rate was set to
108120000 * 7 * 1 * 1 = 756840000. When we was trying to set
172992000 on mdss_pixel_clk_src later.
Since there was no matched ratio, we failed to set it. And dsiclk
divider ratio was set to 15:1 (wrong cached register value 0xf and
didn't update), we finally got 50455997, apparently wrong.
dsi0vco_clk 1 1 0 756839941
dsi0_pll_out_div_clk 1 1 0 756839941
dsi0_pll_post_out_div_clk 0 0 0 216239983
dsi0_pll_bit_clk 2 2 0 756839941
dsi0_phy_pll_out_dsiclk 2 2 0 50455997
disp_cc_mdss_pclk1_clk_src 1 1 0 50455997
dsi0_pll_by_2_bit_clk 0 0 0 378419970
dsi0_phy_pll_out_byteclk 2 2 0 108119991
disp_cc_mdss_byte1_clk_src 2 2 0 108119991
Downstream clk_summary shows the mdss_pixel_clk_src support the
ratio(35:16)
dsi0_phy_pll_out_dsiclk 2 2 0 378420000
disp_cc_mdss_pclk1_clk_src 1 1 0 172992000
dsi0_phy_pll_out_byteclk 2 2 0 108120000
disp_cc_mdss_byte1_clk_src 2 2 0 108120000
After checking downstream source, 15:4 also seems to be supported,
add them two.
Signed-off-by: Pengyu Luo <mitltlatltl@gmail.com>
Reviewed-by: Taniya Das <taniya.das@oss.qualcomm.com>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Link: https://lore.kernel.org/r/20260321095029.2259489-1-mitltlatltl@gmail.com
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Add a driver for the display clock controller on Qualcomm Eliza SoC,
which is copied from SM8750 driver plus changes:
1. Additional DT_HDMI_PHY_PLL_CLK clock input,
2. Eight new HDMI clocks,
3. Different PLLs (lucid and pongo).
Reviewed-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@oss.qualcomm.com>
Link: https://lore.kernel.org/r/20260319-clk-qcom-dispcc-eliza-v3-2-d1f2b19a6e6b@oss.qualcomm.com
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Merge the Eliza display clock controller binding through a topic branch,
to allow the constants to be shared with the DeviceTree branch.
Both sm8350 and sc8280xp use this, on sc8280xp, this would select
gcc-sm8350, we don't neet it on sc8280xp. use depend on to fix it.
Signed-off-by: Pengyu Luo <mitltlatltl@gmail.com>
Reviewed-by: Imran Shaik <imran.shaik@oss.qualcomm.com>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Link: https://lore.kernel.org/r/20260313111018.130068-1-mitltlatltl@gmail.com
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Add bindings for Qualcomm Eliza SoC display clock controller (dispcc),
which is very similar to one in SM8750, except new HDMI-related clocks
and additional clock input from HDMI PHY PLL.
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@oss.qualcomm.com>
Link: https://lore.kernel.org/r/20260319-clk-qcom-dispcc-eliza-v3-1-d1f2b19a6e6b@oss.qualcomm.com
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
The XO clock source is always-on in hardware and cannot be gated.
Without CLK_IS_CRITICAL, runtime PM of downstream consumers (such as
the CMN PLL driver) cascades a disable up to gcc_xo_clk_src, causing
a branch status timeout warning.
The IPQ8074 GCC driver already marks this clock as CLK_IS_CRITICAL.
Apply the same fix to IPQ6018.
Signed-off-by: John Crispin <john@phrozen.org>
Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
Reviewed-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
Link: https://lore.kernel.org/r/20260311182147.30266-1-ansuelsmth@gmail.com
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Use a qcom_cc_driver_data struct instead of a long custom probe
callback to align with modern qcom/gcc-*.c style.
No functional change intended.
Signed-off-by: Val Packett <val@packett.cool>
Reviewed-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Link: https://lore.kernel.org/r/20260312112321.370983-12-val@packett.cool
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Pull fsverity fixes from Eric Biggers:
- Fix a build error on parisc
- Remove the non-large-folio-aware function fsverity_verify_page()
* tag 'fsverity-for-linus' of git://git.kernel.org/pub/scm/fs/fsverity/linux:
fsverity: fix build error by adding fsverity_readahead() stub
fsverity: remove fsverity_verify_page()
f2fs: make f2fs_verify_cluster() partially large-folio-aware
f2fs: remove unnecessary ClearPageUptodate in f2fs_verify_cluster()
Add CLK_OPS_PARENT_ENABLE to MDSS pixel clock sources to ensure parent
clocks are enabled during clock operations, preventing potential
stability issues during display configuration.
Fixes: 80a18f4a8567 ("clk: qcom: Add display clock controller driver for SM8150 and SM8250")
Signed-off-by: Val Packett <val@packett.cool>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Link: https://lore.kernel.org/r/20260312112321.370983-9-val@packett.cool
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Pull crypto library fix from Eric Biggers:
"Fix a big endian specific issue in the PPC64-optimized AES code"
* tag 'libcrypto-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiggers/linux:
lib/crypto: powerpc/aes: Fix rndkey_from_vsx() on big endian CPUs
hppa-linux-gcc 9.5.0 generates a call to fsverity_readahead() in
f2fs_readahead() when CONFIG_FS_VERITY=n, because it fails to do the
expected dead code elimination based on vi always being NULL. Fix the
build error by adding an inline stub for fsverity_readahead(). Since
it's just for opportunistic readahead, just make it a no-op.
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202602180838.pwICdY2r-lkp@intel.com/
Fixes: 45dcb3ac9832 ("f2fs: consolidate fsverity_info lookup")
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20260218012244.18536-1-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@kernel.org>
mdss_gdsc can get stuck on boot due to RCGs being left on from last boot.
As a fix, commit 01a0a6cc8cfd ("clk: qcom: Park shared RCGs upon
registration") introduced a callback to ensure the RCG is off upon init.
However, the fix depends on all shared RCGs being marked as such in code.
For SM8150/SC8180X/SM8250 the MDSS vsync clock was using regular ops,
unlike the same clock in the SC7180 code. This was causing display to
frequently fail to initialize after rebooting on the Surface Pro X.
Fix by using shared ops for this clock.
Fixes: 80a18f4a8567 ("clk: qcom: Add display clock controller driver for SM8150 and SM8250")
Signed-off-by: Val Packett <val@packett.cool>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Link: https://lore.kernel.org/r/20260312112321.370983-8-val@packett.cool
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Stephen retired and stepped back from -next maintainership, update his
entry in CREDITS to recognise his 18 years of hard work making it what
it is today and all the impact it's had on our development process.
Also update to his current GnuPG key while we're here.
Acked-by: Stephen Rothwell <sfr@canb.auug.org.au>
Acked-by: SeongJae Park <sj@kernel.org>
Reviewed-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
Acked-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
I finally got a big endian PPC64 kernel to boot in QEMU. The PPC64 VSX
optimized AES library code does work in that case, with the exception of
rndkey_from_vsx() which doesn't take into account that the order in
which the VSX code stores the round key words depends on the endianness.
So fix rndkey_from_vsx() to do the right thing on big endian CPUs.
Fixes: 7cf2082e74ce ("lib/crypto: powerpc/aes: Migrate POWER8 optimized code into library")
Link: https://lore.kernel.org/r/20260216022104.332991-1-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@kernel.org>
Now that fsverity_verify_page() has no callers, remove it.
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20260218010630.7407-4-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@kernel.org>
README