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 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 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
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"family" is an enum, thus cast of pointer on 64-bit compile test with
clang W=1 causes:
phy-bcm-ns-usb3.c:206:17: error: cast to smaller integer type 'enum bcm_ns_family' from 'const void *' [-Werror,-Wvoid-pointer-to-enum-cast]
This was already fixed in commit bd6e74a2f0a0 ("phy: broadcom: ns-usb3:
fix Wvoid-pointer-to-enum-cast warning") but then got bad in commit
21bf6fc47a1e ("phy: Use device_get_match_data()").
Note that after various discussions the preferred cast is via "unsigned
long", not "uintptr_t".
Fixes: 21bf6fc47a1e ("phy: Use device_get_match_data()")
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@oss.qualcomm.com>
Link: https://patch.msgid.link/20251224115533.154162-2-krzysztof.kozlowski@oss.qualcomm.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
The USB2 Bias Pad Control register manages analog parameters for signal
detection. Previously, the HS_DISCON_LEVEL relied on hardware reset
values, which may lead to the detection failure.
Explicitly configure HS_DISCON_LEVEL to 0x7. This ensures the disconnect
threshold is sufficient to guarantee reliable detection.
Fixes: bbf711682cd5 ("phy: tegra: xusb: Add Tegra186 support")
Cc: stable@vger.kernel.org
Signed-off-by: Wayne Chang <waynec@nvidia.com>
Link: https://patch.msgid.link/20251212032116.768307-1-waynec@nvidia.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
When the OTG USB port is used to power to SoC, configured as peripheral and
used in gadget mode, communication stops without notice about 6 seconds
after the gadget is configured and enumerated.
The problem was observed on a Radxa Rock Pi S board, which can only be
powered by the only USB-C connector. That connector is the only one usable
in gadget mode. This implies the USB cable is connected from before boot
and never disconnects while the kernel runs.
The related code flow in the PHY driver code can be summarized as:
* the first time chg_detect_work starts (6 seconds after gadget is
configured and enumerated)
-> rockchip_chg_detect_work():
if chg_state is UNDEFINED:
property_enable(base, &rphy->phy_cfg->chg_det.opmode, false); [Y]
* rockchip_chg_detect_work() changes state and re-triggers itself a few
times until it reaches the DETECTED state:
-> rockchip_chg_detect_work():
if chg_state is DETECTED:
property_enable(base, &rphy->phy_cfg->chg_det.opmode, true); [Z]
At [Y] all existing communications stop. E.g. using a CDC serial gadget,
the /dev/tty* devices are still present on both host and device, but no
data is transferred anymore. The later call with a 'true' argument at [Z]
does not restore it.
Due to the lack of documentation, what chg_det.opmode does exactly is not
clear, however by code inspection it seems reasonable that is disables
something needed to keep the communication working, and testing proves that
disabling these lines lets gadget mode keep working. So prevent changes to
chg_det.opmode when there is a cable connected (VBUS present).
Fixes: 98898f3bc83c ("phy: rockchip-inno-usb2: support otg-port for rk3399")
Cc: stable@vger.kernel.org
Closes: https://lore.kernel.org/lkml/20250414185458.7767aabc@booty/
Signed-off-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
Reviewed-by: Théo Lebrun <theo.lebrun@bootlin.com>
Link: https://patch.msgid.link/20251127-rk3308-fix-usb-gadget-phy-disconnect-v2-2-dac8a02cd2ca@bootlin.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
When the OTG USB port is used to power the SoC, configured as peripheral
and used in gadget mode, there is a disconnection about 6 seconds after the
gadget is configured and enumerated.
The problem was observed on a Radxa Rock Pi S board, which can only be
powered by the only USB-C connector. That connector is the only one usable
in gadget mode. This implies the USB cable is connected from before boot
and never disconnects while the kernel runs.
The problem happens because of the PHY driver code flow, summarized as:
* UDC start code (triggered via configfs at any time after boot)
-> phy_init
-> rockchip_usb2phy_init
-> schedule_delayed_work(otg_sm_work [A], 6 sec)
-> phy_power_on
-> rockchip_usb2phy_power_on
-> enable clock
-> rockchip_usb2phy_reset
* Now the gadget interface is up and running.
* 6 seconds later otg_sm_work starts [A]
-> rockchip_usb2phy_otg_sm_work():
if (B_IDLE state && VBUS present && ...):
schedule_delayed_work(&rport->chg_work [B], 0);
* immediately the chg_detect_work starts [B]
-> rockchip_chg_detect_work():
if chg_state is UNDEFINED:
if (!rport->suspended):
rockchip_usb2phy_power_off() <--- [X]
At [X], the PHY is powered off, causing a disconnection. This quickly
triggers a new connection and following re-enumeration, but any connection
that had been established during the 6 seconds is broken.
The code already checks for !rport->suspended (which, somewhat
counter-intuitively, means the PHY is powered on), so add a guard for VBUS
as well to avoid a disconnection when a cable is connected.
Fixes: 98898f3bc83c ("phy: rockchip-inno-usb2: support otg-port for rk3399")
Cc: stable@vger.kernel.org
Closes: https://lore.kernel.org/lkml/20250414185458.7767aabc@booty/
Signed-off-by: Louis Chauvet <louis.chauvet@bootlin.com>
Co-developed-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
Signed-off-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
Reviewed-by: Théo Lebrun <theo.lebrun@bootlin.com>
Link: https://patch.msgid.link/20251127-rk3308-fix-usb-gadget-phy-disconnect-v2-1-dac8a02cd2ca@bootlin.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
The mmio regmap that may be allocated during probe is never freed.
Switch to using the device managed allocator so that the regmap is
released on probe failures (e.g. probe deferral) and on driver unbind.
Fixes: 5ab90f40121a ("phy: ti: gmii-sel: Do not use syscon helper to build regmap")
Cc: stable@vger.kernel.org # 6.14
Cc: Andrew Davis <afd@ti.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
Acked-by: Andrew Davis <afd@ti.com>
Link: https://patch.msgid.link/20251127134834.2030-1-johan@kernel.org
Signed-off-by: Vinod Koul <vkoul@kernel.org>
LAN969x uses the SparX-5 SERDES driver, so make it selectable for
ARCH_LAN969X.
Reviewed-by: Daniel Machon <daniel.machon@microchip.com>
Signed-off-by: Robert Marko <robert.marko@sartura.hr>
Tested-by: Gabor Juhos <j4g8y7@gmail.com>
Tested-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Link: https://patch.msgid.link/20251031121834.665987-1-robert.marko@sartura.hr
Signed-off-by: Vinod Koul <vkoul@kernel.org>
devm_pm_runtime_enable() can fail due to memory allocation. The current
code ignores its return value after calling pm_runtime_set_active(),
leaving the device in an inconsistent state if runtime PM initialization
fails.
Check the return value of devm_pm_runtime_enable() and return on
failure. Also move the declaration of 'ret' to the function scope
to support this check.
Fixes: ee8e41b5044f ("phy: ti: phy-da8xx-usb: Add runtime PM support")
Suggested-by: Neil Armstrong <neil.armstrong@linaro.org>
Signed-off-by: Haotian Zhang <vulab@iscas.ac.cn>
Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://patch.msgid.link/20251124105734.1027-1-vulab@iscas.ac.cn
Signed-off-by: Vinod Koul <vkoul@kernel.org>
The "index" variable is used as an index into the usbphyc->phys[] array
which has usbphyc->nphys elements. So if it is equal to usbphyc->nphys
then it is one element out of bounds. The "index" comes from the
device tree so it's data that we trust and it's unlikely to be wrong,
however it's obviously still worth fixing the bug. Change the > to >=.
Fixes: 94c358da3a05 ("phy: stm32: add support for STM32 USB PHY Controller (USBPHYC)")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Reviewed-by: Amelie Delaunay <amelie.delaunay@foss.st.com>
Link: https://patch.msgid.link/aTfHcMJK1wFVnvEe@stanley.mountain
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Enabling runtime PM before attaching the QPHY instance as driver data
can lead to a NULL pointer dereference in runtime PM callbacks that
expect valid driver data. There is a small window where the suspend
callback may run after PM runtime enabling and before runtime forbid.
This causes a sporadic crash during boot:
```
Unable to handle kernel NULL pointer dereference at virtual address 00000000000000a1
[...]
CPU: 0 UID: 0 PID: 11 Comm: kworker/0:1 Not tainted 6.16.7+ #116 PREEMPT
Workqueue: pm pm_runtime_work
pstate: 20000005 (nzCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : qusb2_phy_runtime_suspend+0x14/0x1e0 [phy_qcom_qusb2]
lr : pm_generic_runtime_suspend+0x2c/0x44
[...]
```
Attach the QPHY instance as driver data before enabling runtime PM to
prevent NULL pointer dereference in runtime PM callbacks.
Reorder pm_runtime_enable() and pm_runtime_forbid() to prevent a
short window where an unnecessary runtime suspend can occur.
Use the devres-managed version to ensure PM runtime is symmetrically
disabled during driver removal for proper cleanup.
Fixes: 891a96f65ac3 ("phy: qcom-qusb2: Add support for runtime PM")
Signed-off-by: Loic Poulain <loic.poulain@oss.qualcomm.com>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Reviewed-by: Abel Vesa <abel.vesa@oss.qualcomm.com>
Link: https://patch.msgid.link/20251219085640.114473-1-loic.poulain@oss.qualcomm.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Clear the PCS_TX_SWING_FULL field mask before setting the new value
in PHY_CTRL5 register. Without clearing the mask first, the OR operation
could leave previously set bits, resulting in incorrect register
configuration.
Fixes: 63c85ad0cd81 ("phy: fsl-imx8mp-usb: add support for phy tuning")
Suggested-by: Leonid Segal <leonids@variscite.com>
Acked-by: Pierluigi Passaro <pierluigi.p@variscite.com>
Signed-off-by: Stefano Radaelli <stefano.r@variscite.com>
Reviewed-by: Xu Yang <xu.yang_2@nxp.com>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Reviewed-by: Fabio Estevam <festevam@gmail.com>
Reviewed-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
Link: https://patch.msgid.link/20251219160912.561431-1-stefano.r@variscite.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
The gcc_aux_clk is not required by the PCIe PHY on qcs8300 and is not
specified in the device tree node. Hence, move the qcs8300 phy
compatibility entry into the list of PHYs that require six clocks.
Removed the phy_aux clock from the PCIe PHY binding as it is no longer
used by any instance.
Fixes: e46e59b77a9e ("dt-bindings: phy: qcom,sc8280xp-qmp-pcie-phy: Document the QCS8300 QMP PCIe PHY Gen4 x2")
Signed-off-by: Ziyue Zhang <ziyue.zhang@oss.qualcomm.com>
Acked-by: Manivannan Sadhasivam <mani@kernel.org>
Acked-by: Rob Herring (Arm) <robh@kernel.org>
Reviewed-by: Johan Hovold <johan+linaro@kernel.org>
Link: https://patch.msgid.link/20251128104928.4070050-2-ziyue.zhang@oss.qualcomm.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Currently, the PHY only registers the typec orientation switch when it
is built in. If the typec driver is built as a module, the switch
registration is skipped due to the preprocessor condition, causing
orientation detection to fail.
With commit
45fe729be9a6 ("usb: typec: Stub out typec_switch APIs when CONFIG_TYPEC=n")
the preprocessor condition is not needed anymore and the orientation
switch is correctly registered for both built-in and module builds.
Fixes: b58f0f86fd61 ("phy: fsl-imx8mq-usb: add tca function driver for imx95")
Cc: stable@vger.kernel.org
Suggested-by: Xu Yang <xu.yang_2@nxp.com>
Signed-off-by: Franz Schnyder <franz.schnyder@toradex.com>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Reviewed-by: Xu Yang <xu.yang_2@nxp.com>
Link: https://patch.msgid.link/20251126140136.1202241-1-fra.schnyder@gmail.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Pull SCSI fixes from James Bottomley:
"The only core fix is in doc; all the others are in drivers, with the
biggest impacts in libsas being the rollback on error handling and in
ufs coming from a couple of error handling fixes, one causing a crash
if it's activated before scanning and the other fixing W-LUN
resumption"
* tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
scsi: ufs: qcom: Fix confusing cleanup.h syntax
scsi: libsas: Add rollback handling when an error occurs
scsi: device_handler: Return error pointer in scsi_dh_attached_handler_name()
scsi: ufs: core: Fix a deadlock in the frequency scaling code
scsi: ufs: core: Fix an error handler crash
scsi: Revert "scsi: libsas: Fix exp-attached device scan after probe failure scanned in again after probe failed"
scsi: ufs: core: Fix RPMB link error by reversing Kconfig dependencies
scsi: qla4xxx: Use time conversion macros
scsi: qla2xxx: Enable/disable IRQD_NO_BALANCING during reset
scsi: ipr: Enable/disable IRQD_NO_BALANCING during reset
scsi: imm: Fix use-after-free bug caused by unfinished delayed work
scsi: target: sbp: Remove KMSG_COMPONENT macro
scsi: core: Correct documentation for scsi_device_quiesce()
scsi: mpi3mr: Prevent duplicate SAS/SATA device entries in channel 1
scsi: target: Reset t_task_cdb pointer in error case
scsi: ufs: core: Fix EH failure after W-LUN resume error
Pull ceph updates from Ilya Dryomov:
"We have a patch that adds an initial set of tracepoints to the MDS
client from Max, a fix that hardens osdmap parsing code from myself
(marked for stable) and a few assorted fixups"
* tag 'ceph-for-6.19-rc1' of https://github.com/ceph/ceph-client:
rbd: stop selecting CRC32, CRYPTO, and CRYPTO_AES
ceph: stop selecting CRC32, CRYPTO, and CRYPTO_AES
libceph: make decode_pool() more resilient against corrupted osdmaps
libceph: Amend checking to fix `make W=1` build breakage
ceph: Amend checking to fix `make W=1` build breakage
ceph: add trace points to the MDS client
libceph: fix log output race condition in OSD client
Initializing automatic __free variables to NULL without need (e.g.
branches with different allocations), followed by actual allocation is
in contrary to explicit coding rules guiding cleanup.h:
"Given that the "__free(...) = NULL" pattern for variables defined at
the top of the function poses this potential interdependency problem the
recommendation is to always define and assign variables in one statement
and not group variable definitions at the top of the function when
__free() is used."
Code does not have a bug, but is less readable and uses discouraged
coding practice, so fix that by moving declaration to the place of
assignment.
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@oss.qualcomm.com>
Reviewed-by: Manivannan Sadhasivam <mani@kernel.org>
Link: https://patch.msgid.link/20251208020807.5043-2-krzysztof.kozlowski@oss.qualcomm.com
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>