SMBus 3.1 6.5.7 allows a Block Read byte count of 0, but the
interrupt-driven block-read state machine rejects it as -EPROTO. Worse,
it returns without a NACK+STOP: the next receive cycle has already
started, so the target keeps holding SDA and the bus stays stuck until a
power cycle of this i2c controller.
Accept count=0: NACK the in-flight dummy byte (TXAK) and set msg->len to
2 so i2c_imx_isr_read_continue() emits STOP via its normal last-byte
path. The dummy byte is discarded; block-read callers only consume
buf[0..count-1].
Reading I2DR has likewise already armed the next byte on the
count > I2C_SMBUS_BLOCK_MAX error path, so NACK it (TXAK) before aborting
with -EPROTO; otherwise the failing transfer's STOP cannot complete and
the bus stays held.
The atomic path regressed earlier (v3.16) and is fixed separately; this
patch covers only the v6.13 state-machine rework.
Fixes: 5f5c2d4579 ("i2c: imx: prevent rescheduling in non dma mode")
Signed-off-by: Vincent Jardin <vjardin@free.fr>
Cc: <stable@vger.kernel.org> # v6.13+
Acked-by: Oleksij Rempel <o.rempel@pengutronix.de>
Acked-by: Carlos Song <carlos.song@nxp.com>
Reviewed-by: Stefan Eichenberger <eichest@gmail.com>
Signed-off-by: Andi Shyti <andi.shyti@kernel.org>
Link: https://lore.kernel.org/r/20260713-for-upstream-i2c-lx2160-fix-v1-v3-2-073ac9e103a5@free.fr
SMBus 3.1 6.5.7 allows a Block Read byte count of 0, but the atomic
(polling) path rejects it as -EPROTO. Worse, it returns without a
NACK+STOP: the next receive cycle has already started, so the target
keeps holding SDA and the bus stays stuck until a power cycle for
this i2c controller.
Reading I2DR to obtain the count likewise arms the next byte on the
count > I2C_SMBUS_BLOCK_MAX path, which also returned -EPROTO directly
and left the bus held.
Handle both: NACK the in-flight dummy byte (TXAK) and extend msgs->len so
the existing last-byte handling emits STOP; the dummy byte is discarded.
A count of 0 is a valid empty block read; a count above
I2C_SMBUS_BLOCK_MAX is still reported as -EPROTO, but only after the bus
has been released.
The interrupt-driven path has the same flaw from a later commit and is
fixed separately, as it carries a different Fixes: tag and stable range.
Fixes: 8e8782c715 ("i2c: imx: add SMBus block read support")
Signed-off-by: Vincent Jardin <vjardin@free.fr>
Cc: <stable@vger.kernel.org> # v3.16+
Acked-by: Oleksij Rempel <o.rempel@pengutronix.de>
Acked-by: Carlos Song <carlos.song@nxp.com>
Reviewed-by: Stefan Eichenberger <eichest@gmail.com>
Signed-off-by: Andi Shyti <andi.shyti@kernel.org>
Link: https://lore.kernel.org/r/20260713-for-upstream-i2c-lx2160-fix-v1-v3-1-073ac9e103a5@free.fr
A severe livelock and subsequent Hung Task panic were observed in the
i2c-i801 driver during concurrent Fuzzing. The crash is caused by an
unconditional hardware register cleanup in the error handling path of
i801_access().
When i801_check_pre() fails (e.g., returning -EBUSY because the SMBus
controller is actively used by BIOS/ACPI), the kernel does not actually
acquire the hardware ownership. However, the code jumps to the 'out'
label and executes:
iowrite8(SMBHSTSTS_INUSE_STS | STATUS_FLAGS, SMBHSTSTS(priv));
This forcefully clears the INUSE_STS lock and resets the hardware status
flags without owning the controller. Doing so interrupts ongoing BIOS/ACPI
transactions and totally corrupts the SMBus hardware state machine.
Consequently, all subsequent i801_access() calls fail at the pre-check
stage, triggering an endless stream of "SMBus is busy, can't use it!"
error logs. Over a slow serial console, this printk flood monopolizes
the CPU (Console Livelock), starving other processes trying to acquire
the mmap_lock down_read semaphore, ultimately triggering the hung task
watchdog.
Fix this by moving the 'out' label below the hardware register cleanup.
If i801_check_pre() fails, we safely bypass the iowrite8() and only
release the software locks (pm_runtime and mutex), strictly adhering to
the rule of not releasing resources that were never acquired.
Fixes: 1f760b87e5 ("i2c: i801: Call i801_check_pre() from i801_access()")
Signed-off-by: Mingyu Wang <25181214217@stu.xidian.edu.cn>
Cc: <stable@vger.kernel.org> # v6.3+
Signed-off-by: Andi Shyti <andi.shyti@kernel.org>
Link: https://lore.kernel.org/r/20260512093534.348655-1-w15303746062@163.com
At first glance the harmless cleanup of the driver does nothing bad.
However, as the operator precedence list states the '*' (multiplication)
and '/' division operators have order 5 with left-to-right associativity
the *= has order 17 and associativity right-to-left. It wouldn't be
a problem to replace
foo = foo * HZ / 1000000;
with
foo *= HZ / 1000000;
if HZ constant is in Hertz. The problem is that in the Linux kernel HZ is
defined in jiffy units, which is order of magnitude smaller than a million.
That's why operator precedence has a crucial role here. Fix the regression
by reverting pre-optimized calculations.
Fixes: be40a3ae71 ("i2c: mpc: Use of_property_read_u32 instead of of_get_property")
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: <stable@vger.kernel.org> # v6.4+
Reviewed-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
Signed-off-by: Andi Shyti <andi.shyti@kernel.org>
Link: https://lore.kernel.org/r/20260618144934.3249950-1-andriy.shevchenko@linux.intel.com
On some i.MX platforms, certain I2C client drivers keep a periodic
workqueue which continues to trigger I2C transfers.
During system suspend/resume, there exists a time window between:
- suspend_noirq and the system entering suspend
- the system starting to resume and resume_noirq
In this window, the I2C controller resources such as clock and pinctrl
may already be disabled or not yet restored.
If a workqueue triggers an I2C transfer in this period, the driver
attempts to access I2C registers while the hardware resources are
unavailable, which may lead to system hang.
Mark the I2C adapter as suspended during noirq suspend and block new
transfers until resume, ensuring that I2C transfers are only issued
when hardware resources are available.
Fixes: 1ee867e465 ("i2c: imx-lpi2c: add target mode support")
Signed-off-by: Carlos Song <carlos.song@nxp.com>
Cc: <stable@vger.kernel.org> # v6.14+
Acked-by: Mukesh Savaliya <mukesh.savaliya@oss.qualcomm.com>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Signed-off-by: Andi Shyti <andi.shyti@kernel.org>
Link: https://lore.kernel.org/r/20260525031450.3183421-1-carlos.song@oss.nxp.com
stm32f7_i2c_compute_timing() derives the I2C clock source period
(i2cclk) with DIV_ROUND_CLOSEST, which may round it up. When the
period is overestimated, all timings computed from it (SCLDEL,
SDADEL, SCLL, SCLH) come out shorter on the wire than calculated,
and the resulting bus rate can exceed the requested speed, violating
the I2C specification minimums for tLOW and tHIGH.
For example, with a 104.45 MHz clock source (e.g. PCLK1, the
reset-default I2C clock source on STM32MP1), i2cclk is rounded from
9.574 ns up to 10 ns. Requesting a 400 kHz fast mode bus with
72/27 ns rise/fall times and no analog/digital filters then produces
an actual bus rate of 415.6 kHz with tLOW = 1254 ns, violating both
the 400 kHz maximum rate and the 1300 ns tLOW minimum of the
specification.
Truncate the period instead, so that it can only be underestimated.
The error then falls on the safe side: the programmed timings come
out slightly longer than computed and the bus runs marginally below
the target rate (375.3 kHz in the example above) while meeting the
specification.
i2cbus is left rounded-to-closest: it is only used as the target of
the clk_error comparison and is never multiplied into the programmed
timings, so nearest rounding remains accurate there.
Fixes: aeb068c572 ("i2c: i2c-stm32f7: add driver")
Signed-off-by: Guillermo Rodríguez <guille.rodriguez@gmail.com>
Cc: <stable@vger.kernel.org> # v4.14+
Acked-by: Alain Volmat <alain.volmat@foss.st.com>
Reviewed-by: Pierre-Yves MORDRET <pierre-yves.mordret@foss.st.com>
Signed-off-by: Andi Shyti <andi.shyti@kernel.org>
Link: https://lore.kernel.org/r/20260611104857.242153-1-guille.rodriguez@gmail.com
The event ISR reads SR1 and, when an error flag (ARLO/AF/BERR) is set,
calls loongson2_i2c_isr_error() which clears the offending flag, issues
STOP for the AF case, records msg->result, masks every CR2 interrupt
enable and completes the waiter. The handler then returns IRQ_NONE,
declaring to the IRQ core that the device did not interrupt.
That report is wrong. The device did interrupt and the handler fully
serviced it. Because the IRQ is requested with IRQF_SHARED, the genirq
spurious-IRQ tracker counts each error as unhandled. A bus that emits
sporadic NACKs, arbitration losses or bus errors will therefore march
toward the spurious-IRQ threshold and the line can end up disabled,
wedging the controller.
Return IRQ_HANDLED on this path. The other IRQ_NONE site, taken when
neither an event nor an error bit is set, remains correct.
Fixes: 6d1b0785f6 ("i2c: ls2x-v2: Add driver for Loongson-2K0300 I2C controller")
Signed-off-by: David Carlier <devnexen@gmail.com>
Assisted-by: Codex:GPT-5.5
Reviewed-by: Binbin Zhou <zhoubinbin@loongson.cn>
Tested-by: Binbin Zhou <zhoubinbin@loongson.cn>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Andi Shyti <andi.shyti@kernel.org>
Link: https://lore.kernel.org/r/20260506154015.94815-1-devnexen@gmail.com
Pull i2c updates from Andi Shyti:
"This pull request is mostly made of cleanups and small infrastructure
improvements across the I2C core, drivers and bindings. It also adds
support for three drivers and a few new compatibles.
Two major cleanup across drivers and core code:
- use named initializers in device ID tables
- replace dev_err() with dev_err_probe()
Drivers:
- at24: use named initializers for arrays of i2c_device_data
- at91: add MCHP_LAN966X_PCI dependency
- cadence: add shutdown callback
- k1: enable by default on SpacemiT
- mxs: improve documentation
- qcom-geni: use pm_runtime_force_suspend/resume for system sleep
- tegra:
- disable fair arbitration on non-MCTP buses
- allocate DMA buffers from the correct DMA device
- designware:
- handle active target shutdown cleanly
- add shutdown callbacks for platform and PCI drivers
- adopt the new PM_RUNTIME_ACQUIRE() helpers
DT bindings:
- convert davinci bindings to DT schema
Core and muxes:
- acpi: report missing I2C resources as -ENOENT
- gpiolib: add gpiod_is_single_ended() helper for I2C GPIO users
- i2c-mux-reg: add generic firmware node support
- a set of 10 patches from Johan Hovold fixing adapter registration
races, cleanup paths and resource management issues
New support:
- DesignWare LECA0003 (ACPI ID)
- Loongson LS2K0300 I2C controller (new driver)
- Qualcomm CCI Glymur and Shikra compatibles"
* tag 'i2c-7.2-part1' of git://git.kernel.org/pub/scm/linux/kernel/git/andi.shyti/linux: (46 commits)
i2c: mxs: add missing kernel-doc for struct mxs_i2c_dev members
i2c: qcom-geni: Use pm_runtime_force_{suspend,resume} helpers
dt-bindings: i2c: qcom-cci: Document Glymur compatible
dt-bindings: i2c: qcom-cci: Document Shikra compatible
i2c: mux: reg: use device property accessors
i2c: acpi: Return -ENOENT when no resources found in i2c_acpi_client_count()
i2c: at91: Add MCHP_LAN966X_PCI dependency
i2c: eg20t: Consistently define pci_device_ids using named initializers
i2c: designware-pcidrv: Consistently define pci_device_ids using named initializers
i2c: bcm-kona: fix spelling mistake in timeout-check comment
i2c: cadence: Add shutdown handler
i2c: tegra: Disable fair arbitration for non-MCTP buses
i2c: tegra: use dmaengine_get_dma_device() for DMA buffer allocation
i2c: busses: make K1 driver default for SpacemiT platforms
i2c: Use named initializers for arrays of i2c_device_data
i2c: core: clean up adapter registration error label
i2c: core: clean up bus id allocation
i2c: core: fix adapter deregistration race
i2c: core: fix adapter registration race
i2c: core: disable runtime PM on adapter registration failure
...
Pull driver core updates from Danilo Krummrich:
"Deferred probe:
- Fix race where deferred probe timeout work could be permanently
canceled by using mod_delayed_work()
- Fix missing jiffies conversion in deferred_probe_extend_timeout()
- Guard timeout extension with delayed_work_pending() to prevent
premature firing
- Use system_percpu_wq instead of the deprecated system_wq
- Update deferred_probe_timeout documentation
device:
- Replace direct struct device bitfield access (can_match, dma_iommu,
dma_skip_sync, dma_ops_bypass, state_synced, dma_coherent,
of_node_reused, offline, offline_disabled) with flag-based
accessors using bit operations
- Reject devices with unregistered buses
- Delete unused DEVICE_ATTR_PREALLOC()
- Add low-level device attribute macros with const show/store
callbacks, allowing device attributes to reside in read-only memory
- Move core device attributes to read-only memory
- Constify group array pointers in driver_add_groups() /
driver_remove_groups(), struct bus_type, and struct device_driver
device property:
- Fix fwnode reference leak in fwnode_graph_get_endpoint_by_id()
- Initialize all fields of fwnode_handle in fwnode_init()
- Provide swnode_get()/swnode_put() wrappers around kobject_get/put()
- Allow passing struct software_node_ref_args pointers directly to
PROPERTY_ENTRY_REF()
driver_override:
- Migrate amba, cdx, vmbus, and rpmsg to the generic driver_override
infrastructure, fixing a UAF from unsynchronized access to
driver_override in bus match() callbacks
- Remove the now-unused driver_set_override()
firmware loader:
- Fix recursive lock deadlock in device_cache_fw_images() when async
work falls back to synchronous execution
- Fix device reference leak in firmware_upload_register()
platform:
- Pass KBUILD_MODNAME through the platform driver registration macro
to create module symlinks in sysfs for built-in drivers; move
module_kset initialization to a pure_initcall and tegra cbb
registration to core_initcall to ensure correct ordering
- Pass THIS_MODULE implicitly through a coresight_init_driver() macro
sysfs:
- Upgrade OOB write detection in sysfs_kf_seq_show() from printk to
WARN
- Add return value clamping to sysfs_kf_read()
Rust:
- ACPI:
Fix missing match data for PRP0001 by exporting
acpi_of_match_device()
- Auxiliary:
Replace drvdata() with dedicated registration data on
auxiliary_device. drvdata() exposed the driver's bus device private
data beyond the driver's own scope, creating ordering constraints
and forcing the data to outlive all registrations that access it.
Registration data is instead scoped structurally to the
Registration object, making lifecycle ordering enforced by
construction rather than convention.
- Rust-native device driver lifetimes (HRT):
Allow Rust device drivers to carry a lifetime parameter on their
bus device private data, tied to the device binding scope -- the
interval during which a bus device is bound to a driver. Device
resources like pci::Bar<'a> and IoMem<'a> can be stored directly in
the driver's bus device private data with a lifetime bounded by the
binding scope, so the compiler enforces at build time that they do
not outlive the binding. This removes Devres indirection from every
access site and eliminates try_access() failure paths in
destructors.
Bus driver traits use a Generic Associated Type (GAT) Data<'bound>
to introduce the lifetime on the private data, rather than
parameterizing the Driver trait itself. Auxiliary registration
data, where the lifetime is not introduced by a trait callback but
must be threaded through Registration, uses the ForLt trait (a
type-level abstraction for types generic over a lifetime).
Misc:
- Fix DT overlayed devices not probing by reverting the broken
treewide overlay fix and re-running fw_devlink consumer pickup when
an overlay is applied to a bound device
- Use root_device_register() for faux bus root device; add sanity
check for failed bus init
- Fix dev_has_sync_state() data race with READ_ONCE() and move it to
base.h
- Avoid spurious device_links warning when removing a device while
its supplier is unbinding
- Switch ISA bus to dynamic root device
- Fix suspicious RCU usage in kernfs_put()
- Remove devcoredump exit callback
- Constify devfreq_event_class"
* tag 'driver-core-7.2-rc1' of gitolite.kernel.org:pub/scm/linux/kernel/git/driver-core/driver-core: (81 commits)
software node: allow passing reference args to PROPERTY_ENTRY_REF()
driver core: platform: set mod_name in driver registration
coresight: pass THIS_MODULE implicitly through a macro
kernel: param: initialize module_kset in a pure_initcall
soc/tegra: cbb: Move driver registration from pure_initcall to core_initcall
firmware_loader: Fix recursive lock in device_cache_fw_images()
driver core: Use system_percpu_wq instead of system_wq
driver core: remove driver_set_override()
rpmsg: use generic driver_override infrastructure
Drivers: hv: vmbus: use generic driver_override infrastructure
cdx: use generic driver_override infrastructure
amba: use generic driver_override infrastructure
rust: devres: add 'static bound to Devres<T>
samples: rust: rust_driver_auxiliary: showcase lifetime-bound registration data
rust: auxiliary: generalize Registration over ForLt
rust: types: add `ForLt` trait for higher-ranked lifetime support
gpu: nova-core: separate driver type from driver data
samples: rust: rust_driver_pci: use HRT lifetime for Bar
rust: io: make IoMem and ExclusiveIoMem lifetime-parameterized
rust: pci: make Bar lifetime-parameterized
...
The driver carries custom system suspend/resume handling that manually
tracks a suspended state and conditionally calls
geni_i2c_runtime_suspend()
from the noirq suspend path, then adjusts runtime PM state by hand. This
duplicates PM core behavior and adds unnecessary complexity.
Drop the manual state tracking and switch to pm_runtime_force_suspend()
and pm_runtime_force_resume() for system sleep. These helpers already
perform the required checks, call the runtime PM callbacks when needed,
and keep runtime PM state transitions consistent.
Reviewed-by: Mukesh Kumar Savaliya <mukesh.savaliya@oss.qualcomm.com>
Signed-off-by: Praveen Talari <praveen.talari@oss.qualcomm.com>
Signed-off-by: Andi Shyti <andi.shyti@kernel.org>
Link: https://lore.kernel.org/r/20260520-use_pm_runtime_apis-v1-1-6a5238fc6cb6@oss.qualcomm.com
Convert the device-tree parsing path to the generic fwnode/device
property accessors so the driver can be probed on ACPI and swnode
platforms as well as OF. The helper is renamed from
i2c_mux_reg_probe_dt() to i2c_mux_reg_probe_fw() to reflect that.
Accessor translation:
of_parse_phandle("i2c-parent") +
of_find_i2c_adapter_by_node() -> fwnode_find_reference() +
i2c_find_adapter_by_fwnode()
of_get_child_count() -> device_get_child_node_count()
of_property_read_bool() -> device_property_read_bool()
for_each_child_of_node() -> device_for_each_child_node()
of_property_read_u32("reg") on ACPI device nodes:
acpi_get_local_address()
everything else (OF, swnode,
ACPI data nodes):
fwnode_property_read_u32()
of_property_read_u32("idle-state") -> device_property_read_u32()
The child-node branch uses is_acpi_device_node() rather than
is_acpi_node(): the latter also matches ACPI data nodes (the
_DSD hierarchical-property children used by PRP0001-style
firmware), which have no ACPI handle and would make
acpi_get_local_address() fall back to evaluating _ADR against the
root namespace and return -ENODATA. Routing data nodes through
fwnode_property_read_u32() instead lets them resolve the "reg"
property the same way OF and swnode children do.
Behavioural preservations (deliberate, to avoid regressing existing
users):
- The three-way endian fallback is kept verbatim: an explicit
"little-endian" property wins, then "big-endian", and otherwise
the host's compile-time byte order. device_is_big_endian() is
not used here because it ignores "little-endian" and introduces
"native-endian" semantics, which would diverge from the binding.
- The "if (!mux->data.reg)" guard around
devm_platform_get_and_ioremap_resource() in probe() is kept.
drivers/platform/mellanox/mlx-platform.c registers i2c-mux-reg
platform_devices with no memory resource and supplies a
pre-set .reg / .reg_size through struct
i2c_mux_reg_platform_data; without the guard those
registrations would fail in probe().
- The "if (!mux->data.reg)" ioremap block (and the paired
reg_size validation that depends on it) is hoisted above
i2c_get_adapter(mux->data.parent), so the fwnode path
preserves master's ordering of "ioremap before parent-adapter
get". For platdata users the validation runs from a slightly
earlier position, but mux->data.reg_size is already set from
platdata by then, so the order is functionally neutral.
The OF-only of_address_to_resource() translation in the old
probe_dt() is dropped because the same address is available from
the platform_device resource table on OF as well as ACPI, and the
existing fallback in probe() ioremaps it.
Acked-by: Peter Rosin <peda@lysator.liu.se>
Signed-off-by: Abdurrahman Hussain <abdurrahman@nexthop.ai>
Assisted-by: Claude-Code:claude-opus-4-7
Assisted-by: sashiko:gemini-3.1-pro-preview
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Andi Shyti <andi.shyti@kernel.org>
Some users want to return an error to the upper layers when
i2c_acpi_client_count() returns 0. Follow the common pattern
in such cases, i.e. return -ENOENT instead of 0.
While at it, fix the kernel-doc warning about missing return value
description.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Andi Shyti <andi.shyti@kernel.org>
The LPI2C driver requests DMA channels using dma_request_chan(), but
never releases them in lpi2c_imx_remove(), resulting in DMA channel
leaks every time the driver is unloaded.
Additionally, when lpi2c_dma_init() successfully requests the TX DMA
channel but fails to request the RX DMA channel, the probe falls back
to PIO mode and completes successfully. Since probe succeeds, the devres
framework will not trigger any cleanup, leaving the TX DMA channel and
the memory allocated for the dma structure held for the lifetime of the
device even though DMA is never used.
Switch to devm_dma_request_chan() to let the device core manage DMA
channel lifetime automatically. Wrap all allocations within a devres
group so that devres_release_group() can release all partially acquired
resources when DMA init fails and probe continues in PIO mode.
Fixes: a09c8b3f90 ("i2c: imx-lpi2c: add eDMA mode support for LPI2C")
Signed-off-by: Carlos Song <carlos.song@nxp.com>
Cc: <stable@vger.kernel.org> # v6.14+
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Signed-off-by: Andi Shyti <andi.shyti@kernel.org>
Link: https://lore.kernel.org/r/20260520093323.2882070-1-carlos.song@oss.nxp.com
Recent Tegra I2C controllers have a fairness arbitration register, which
allows configuring the fair idle time required to support MCTP protocol
over I2C. It is enabled by default, adding a per-transfer latency overhead
that impacts non-MCTP I2C buses.
Disable the fairness arbitration register during controller init for buses
that are not MCTP controllers.
Assisted-by: Cursor:claude-4.6-opus
Signed-off-by: Akhil R <akhilrajeev@nvidia.com>
Reviewed-by: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Andi Shyti <andi.shyti@kernel.org>
Link: https://lore.kernel.org/r/20260518114013.62065-3-akhilrajeev@nvidia.com
Use dmaengine_get_dma_device() to obtain the correct struct device
pointer for dma_alloc_coherent() instead of directly dereferencing
chan->device->dev.
The dmaengine_get_dma_device() helper checks whether the DMA channel
has a per-channel DMA device (chan->dev->chan_dma_dev) and returns it
when available, falling back to the controller device otherwise. On
platforms where the DMA controller sits behind an IOMMU with
per-channel IOVA spaces (e.g. Tegra264 GPC DMA), the per-channel
device carries the correct DMA mapping context. Using the controller
device directly would allocate DMA buffers against the wrong IOMMU
domain, leading to SMMU faults at runtime.
On platforms without per-channel DMA devices the helper returns the
same pointer as before, so there is no change in behavior for existing
hardware.
Assisted-by: Cursor:claude-4.6-opus
Signed-off-by: Akhil R <akhilrajeev@nvidia.com>
Reviewed-by: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Andi Shyti <andi.shyti@kernel.org>
Link: https://lore.kernel.org/r/20260518114013.62065-2-akhilrajeev@nvidia.com
The Tegra I2C driver relies on runtime PM to wake up the controller before
each transfer. However, runtime PM is disabled between the system suspend
and NOIRQ suspend. If an I2C device initiates a transfer during this
window, the I2C controller fails to wake up and the transfer fails. To
handle this, the controller must be kept available for this period to
allow transfers.
Rework the I2C controller's system PM callbacks such that the controller
is resumed from runtime suspend during system suspend and it stays
RPM_ACTIVE throughout the suspend-resume cycle until it is runtime
suspended back in the system resume. The clocks are disabled in NOIRQ
suspend and enabled back in NOIRQ resume by calling the controller's
runtime PM functions directly.
Fixes: 8ebf15e9c8 ("i2c: tegra: Move suspend handling to NOIRQ phase")
Assisted-by: Cursor:claude-4.6-opus
Signed-off-by: Akhil R <akhilrajeev@nvidia.com>
Cc: <stable@vger.kernel.org> # v5.4+
Reviewed-by: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Andi Shyti <andi.shyti@kernel.org>
Link: https://lore.kernel.org/r/20260518114013.62065-5-akhilrajeev@nvidia.com
On all modern platforms Qualcomm CCI controller provides two I2C masters,
and on particular boards only one I2C master may be initialized, and in
such cases the device unbinding or driver removal causes a NULL pointer
dereference, because cci_halt() is called for all two I2C masters, but
a completion is initialized only for the single enabled master:
% rmmod i2c-qcom-cci
Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000
<snip>
Call trace:
__wait_for_common+0x194/0x1a8 (P)
wait_for_completion_timeout+0x20/0x2c
cci_remove+0xc4/0x138 [i2c_qcom_cci]
platform_remove+0x20/0x30
device_remove+0x4c/0x80
device_release_driver_internal+0x1c8/0x224
driver_detach+0x50/0x98
bus_remove_driver+0x6c/0xbc
driver_unregister+0x30/0x60
platform_driver_unregister+0x14/0x20
qcom_cci_driver_exit+0x18/0x1008 [i2c_qcom_cci]
....
Fixes: e517526195 ("i2c: Add Qualcomm CCI I2C driver")
Signed-off-by: Vladimir Zapolskiy <vladimir.zapolskiy@linaro.org>
Cc: <stable@vger.kernel.org> # v5.8+
Reviewed-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
Signed-off-by: Andi Shyti <andi.shyti@kernel.org>
Link: https://lore.kernel.org/r/20260515234121.1607425-2-vladimir.zapolskiy@linaro.org
stm32f7_i2c_compute_timing() uses i2c_dev->analog_filter to pick
the analog filter delay, but i2c_dev->analog_filter is parsed from
the "i2c-analog-filter" DT property only after the compute_timing
loop in stm32f7_i2c_setup_timing(), so in practice the timing
calculations always ignore the analog filter. On an STM32MP1 board
with clock-frequency = <400000> and i2c-analog-filter set, measured
SCL frequency was ~382 kHz.
This also affects (widens) the computed SDADEL range. At high bus
clock speeds, this can select an SDADEL value that violates tVD;DAT
(data valid time).
Fix by parsing "i2c-analog-filter" before the compute_timing loop.
Fixes: 83c3408f7b ("i2c: stm32f7: support DT binding i2c-analog-filter")
Signed-off-by: Guillermo Rodríguez <guille.rodriguez@gmail.com>
Cc: <stable@vger.kernel.org> # v5.13+
Acked-by: Alain Volmat <alain.volmat@foss.st.com>
Signed-off-by: Andi Shyti <andi.shyti@kernel.org>
Link: https://lore.kernel.org/r/20260526091210.20383-1-guille.rodriguez@gmail.com
In i2c_imx_runtime_suspend(), the clock is disabled before switching
the pinctrl state to sleep. If pinctrl_pm_select_sleep_state() fails,
the runtime suspend is aborted but the clock remains disabled, causing
a system crash when the hardware is subsequently accessed.
Fix this by switching the pinctrl state before disabling the clock so
that a pinctrl failure leaves the clock enabled and the hardware
accessible.
In i2c_imx_runtime_resume(), restore the pinctrl state back to sleep
if clk_enable() fails to keep the consistent.
Fixes: 576eba03c9 ("i2c: imx: switch different pinctrl state in different system power status")
Signed-off-by: Carlos Song <carlos.song@nxp.com>
Cc: <stable@vger.kernel.org> # v6.14+
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Signed-off-by: Andi Shyti <andi.shyti@kernel.org>
Link: https://lore.kernel.org/r/20260521065038.2954998-1-carlos.song@oss.nxp.com
When riic_i2c_resume_noirq() is called, it deasserts the reset
using reset_control_deassert(), which for shared resets increments
a reference count. If pm_runtime_force_resume() then fails, the
function returns without calling reset_control_assert() to
decrement the count. This leaves the reset deasserted and the
reference count unbalanced, which can prevent other users of the
shared reset from properly asserting it later.
Fix the leak by calling reset_control_assert() on the error
handling path for a failed pm_runtime_force_resume().
Fixes: e383f09614 ("i2c: riic: Move suspend handling to NOIRQ phase")
Signed-off-by: Wentao Liang <vulab@iscas.ac.cn>
Cc: <stable@vger.kernel.org> # v6.19+
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Andi Shyti <andi.shyti@kernel.org>
Link: https://lore.kernel.org/r/20260608071123.128964-1-vulab@iscas.ac.cn
While being less compact, using named initializers allows to more easily
see which members of the structs are assigned which value without having
to lookup the declaration of the struct. And it's also more robust
against changes to the struct definition.
The mentioned robustness is relevant for a planned change to struct
i2c_device_id that replaces .driver_data by an anonymous union.
While touching all these arrays, unify usage of whitespace in the list
terminator.
This patch doesn't modify the compiled arrays, only their representation
in source form benefits. The former was confirmed with x86 and arm64
builds.
Signed-off-by: Uwe Kleine-König (The Capable Hub) <u.kleine-koenig@baylibre.com>
Reviewed-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Link: https://lore.kernel.org/r/20260518164510.805502-2-u.kleine-koenig@baylibre.com
Signed-off-by: Andi Shyti <andi.shyti@kernel.org>
Clean up the adapter registration error labels by making sure that also
the last one is named after what it does.
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Clean up bus id allocation by using a common helper and deferring it
until it is needed during adapter registration.
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Adapters can be looked up by their id using i2c_get_adapter() which
takes a reference to the embedded struct device.
Remove the adapter from the IDR before tearing it down during
deregistration (and on registration failure) to make sure its resources
are not accessed after having been freed (e.g. the device name).
Fixes: 35fc37f818 ("i2c: Limit core locking to the necessary sections")
Cc: stable@vger.kernel.org # 2.6.31
Cc: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Adapters can be looked up based on their id using i2c_get_adapter()
which takes a reference to the embedded struct device.
Make sure that the adapter (including its struct device) has been
initialised before adding it to the IDR to avoid accessing uninitialised
data which could, for example, lead to NULL-pointer dereferences or
use-after-free.
Note that the i2c-dev chardev, which is registered from a bus notifier,
currently uses i2c_get_adapter() so the adapter needs to be added to the
IDR before registration.
Fixes: 6e13e64184 ("i2c: Add i2c_add_numbered_adapter()")
Cc: stable@vger.kernel.org # 2.6.22
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Runtime PM is disabled by driver core when deregistering a device (and
on registration failure) but add an explicit disable to balance the
enable call when adapter registration fails for symmetry.
Fixes: 23a698fe65 ("i2c: core: treat EPROBE_DEFER when acquiring SCL/SDA GPIOs")
Cc: Codrin Ciubotariu <codrin.ciubotariu@microchip.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Clients can be registered from bus notifier callbacks so the debugfs
directory needs to be created before registering the adapter as clients
use that directory as their debugfs parent.
Move debugfs creation before adapter registration to avoid having
clients create their debugfs directories in the debugfs root (which is
also more likely to fail due to name collisions).
Note that failure to allocate the adapter name must now be handled
explicitly as debugfs_create_dir() cannot handle a NULL name (unlike
device_add() which returns an error).
Fixes: 73febd775b ("i2c: create debugfs entry per adapter")
Cc: stable@vger.kernel.org # 6.8
Cc: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Drivers must not probe defer after having registered devices as that
will trigger a probe loop if the devices bind to a driver (cf. commit
fbc35b45f9 ("Add documentation on meaning of -EPROBE_DEFER")).
Move the recovery initialisation, where the GPIO lookup may fail, before
registering the adapter to prevent this.
Fixes: 75820314de ("i2c: core: add generic I2C GPIO recovery")
Cc: stable@vger.kernel.org # 5.9
Cc: Codrin Ciubotariu <codrin.ciubotariu@microchip.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
If adapter registration ever fails the release callback would trigger a
NULL-pointer dereference as the completion struct has not been
initialised.
Note that before the offending commit this would instead have resulted
in a minor memory leak of the adapter name.
Fixes: 3f8c4f5e9a ("i2c: core: fix reference leak in i2c_register_adapter()")
Cc: stable@vger.kernel.org
Cc: Joe Hattori <joe@pf.is.s.u-tokyo.ac.jp>
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
