aboutsummaryrefslogtreecommitdiff
path: root/Documentation/hwmon/submitting-patches.rst
diff options
context:
space:
mode:
authorLibravatar Linus Torvalds <torvalds@linux-foundation.org>2023-02-21 18:24:12 -0800
committerLibravatar Linus Torvalds <torvalds@linux-foundation.org>2023-02-21 18:24:12 -0800
commit5b7c4cabbb65f5c469464da6c5f614cbd7f730f2 (patch)
treecc5c2d0a898769fd59549594fedb3ee6f84e59a0 /Documentation/hwmon/submitting-patches.rst
downloadlinux-5b7c4cabbb65f5c469464da6c5f614cbd7f730f2.tar.gz
linux-5b7c4cabbb65f5c469464da6c5f614cbd7f730f2.zip
Merge tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-nextgrafted
Pull networking updates from Jakub Kicinski: "Core: - Add dedicated kmem_cache for typical/small skb->head, avoid having to access struct page at kfree time, and improve memory use. - Introduce sysctl to set default RPS configuration for new netdevs. - Define Netlink protocol specification format which can be used to describe messages used by each family and auto-generate parsers. Add tools for generating kernel data structures and uAPI headers. - Expose all net/core sysctls inside netns. - Remove 4s sleep in netpoll if carrier is instantly detected on boot. - Add configurable limit of MDB entries per port, and port-vlan. - Continue populating drop reasons throughout the stack. - Retire a handful of legacy Qdiscs and classifiers. Protocols: - Support IPv4 big TCP (TSO frames larger than 64kB). - Add IP_LOCAL_PORT_RANGE socket option, to control local port range on socket by socket basis. - Track and report in procfs number of MPTCP sockets used. - Support mixing IPv4 and IPv6 flows in the in-kernel MPTCP path manager. - IPv6: don't check net.ipv6.route.max_size and rely on garbage collection to free memory (similarly to IPv4). - Support Penultimate Segment Pop (PSP) flavor in SRv6 (RFC8986). - ICMP: add per-rate limit counters. - Add support for user scanning requests in ieee802154. - Remove static WEP support. - Support minimal Wi-Fi 7 Extremely High Throughput (EHT) rate reporting. - WiFi 7 EHT channel puncturing support (client & AP). BPF: - Add a rbtree data structure following the "next-gen data structure" precedent set by recently added linked list, that is, by using kfunc + kptr instead of adding a new BPF map type. - Expose XDP hints via kfuncs with initial support for RX hash and timestamp metadata. - Add BPF_F_NO_TUNNEL_KEY extension to bpf_skb_set_tunnel_key to better support decap on GRE tunnel devices not operating in collect metadata. - Improve x86 JIT's codegen for PROBE_MEM runtime error checks. - Remove the need for trace_printk_lock for bpf_trace_printk and bpf_trace_vprintk helpers. - Extend libbpf's bpf_tracing.h support for tracing arguments of kprobes/uprobes and syscall as a special case. - Significantly reduce the search time for module symbols by livepatch and BPF. - Enable cpumasks to be used as kptrs, which is useful for tracing programs tracking which tasks end up running on which CPUs in different time intervals. - Add support for BPF trampoline on s390x and riscv64. - Add capability to export the XDP features supported by the NIC. - Add __bpf_kfunc tag for marking kernel functions as kfuncs. - Add cgroup.memory=nobpf kernel parameter option to disable BPF memory accounting for container environments. Netfilter: - Remove the CLUSTERIP target. It has been marked as obsolete for years, and we still have WARN splats wrt races of the out-of-band /proc interface installed by this target. - Add 'destroy' commands to nf_tables. They are identical to the existing 'delete' commands, but do not return an error if the referenced object (set, chain, rule...) did not exist. Driver API: - Improve cpumask_local_spread() locality to help NICs set the right IRQ affinity on AMD platforms. - Separate C22 and C45 MDIO bus transactions more clearly. - Introduce new DCB table to control DSCP rewrite on egress. - Support configuration of Physical Layer Collision Avoidance (PLCA) Reconciliation Sublayer (RS) (802.3cg-2019). Modern version of shared medium Ethernet. - Support for MAC Merge layer (IEEE 802.3-2018 clause 99). Allowing preemption of low priority frames by high priority frames. - Add support for controlling MACSec offload using netlink SET. - Rework devlink instance refcounts to allow registration and de-registration under the instance lock. Split the code into multiple files, drop some of the unnecessarily granular locks and factor out common parts of netlink operation handling. - Add TX frame aggregation parameters (for USB drivers). - Add a new attr TCA_EXT_WARN_MSG to report TC (offload) warning messages with notifications for debug. - Allow offloading of UDP NEW connections via act_ct. - Add support for per action HW stats in TC. - Support hardware miss to TC action (continue processing in SW from a specific point in the action chain). - Warn if old Wireless Extension user space interface is used with modern cfg80211/mac80211 drivers. Do not support Wireless Extensions for Wi-Fi 7 devices at all. Everyone should switch to using nl80211 interface instead. - Improve the CAN bit timing configuration. Use extack to return error messages directly to user space, update the SJW handling, including the definition of a new default value that will benefit CAN-FD controllers, by increasing their oscillator tolerance. New hardware / drivers: - Ethernet: - nVidia BlueField-3 support (control traffic driver) - Ethernet support for imx93 SoCs - Motorcomm yt8531 gigabit Ethernet PHY - onsemi NCN26000 10BASE-T1S PHY (with support for PLCA) - Microchip LAN8841 PHY (incl. cable diagnostics and PTP) - Amlogic gxl MDIO mux - WiFi: - RealTek RTL8188EU (rtl8xxxu) - Qualcomm Wi-Fi 7 devices (ath12k) - CAN: - Renesas R-Car V4H Drivers: - Bluetooth: - Set Per Platform Antenna Gain (PPAG) for Intel controllers. - Ethernet NICs: - Intel (1G, igc): - support TSN / Qbv / packet scheduling features of i226 model - Intel (100G, ice): - use GNSS subsystem instead of TTY - multi-buffer XDP support - extend support for GPIO pins to E823 devices - nVidia/Mellanox: - update the shared buffer configuration on PFC commands - implement PTP adjphase function for HW offset control - TC support for Geneve and GRE with VF tunnel offload - more efficient crypto key management method - multi-port eswitch support - Netronome/Corigine: - add DCB IEEE support - support IPsec offloading for NFP3800 - Freescale/NXP (enetc): - support XDP_REDIRECT for XDP non-linear buffers - improve reconfig, avoid link flap and waiting for idle - support MAC Merge layer - Other NICs: - sfc/ef100: add basic devlink support for ef100 - ionic: rx_push mode operation (writing descriptors via MMIO) - bnxt: use the auxiliary bus abstraction for RDMA - r8169: disable ASPM and reset bus in case of tx timeout - cpsw: support QSGMII mode for J721e CPSW9G - cpts: support pulse-per-second output - ngbe: add an mdio bus driver - usbnet: optimize usbnet_bh() by avoiding unnecessary queuing - r8152: handle devices with FW with NCM support - amd-xgbe: support 10Mbps, 2.5GbE speeds and rx-adaptation - virtio-net: support multi buffer XDP - virtio/vsock: replace virtio_vsock_pkt with sk_buff - tsnep: XDP support - Ethernet high-speed switches: - nVidia/Mellanox (mlxsw): - add support for latency TLV (in FW control messages) - Microchip (sparx5): - separate explicit and implicit traffic forwarding rules, make the implicit rules always active - add support for egress DSCP rewrite - IS0 VCAP support (Ingress Classification) - IS2 VCAP filters (protos, L3 addrs, L4 ports, flags, ToS etc.) - ES2 VCAP support (Egress Access Control) - support for Per-Stream Filtering and Policing (802.1Q, 8.6.5.1) - Ethernet embedded switches: - Marvell (mv88e6xxx): - add MAB (port auth) offload support - enable PTP receive for mv88e6390 - NXP (ocelot): - support MAC Merge layer - support for the the vsc7512 internal copper phys - Microchip: - lan9303: convert to PHYLINK - lan966x: support TC flower filter statistics - lan937x: PTP support for KSZ9563/KSZ8563 and LAN937x - lan937x: support Credit Based Shaper configuration - ksz9477: support Energy Efficient Ethernet - other: - qca8k: convert to regmap read/write API, use bulk operations - rswitch: Improve TX timestamp accuracy - Intel WiFi (iwlwifi): - EHT (Wi-Fi 7) rate reporting - STEP equalizer support: transfer some STEP (connection to radio on platforms with integrated wifi) related parameters from the BIOS to the firmware. - Qualcomm 802.11ax WiFi (ath11k): - IPQ5018 support - Fine Timing Measurement (FTM) responder role support - channel 177 support - MediaTek WiFi (mt76): - per-PHY LED support - mt7996: EHT (Wi-Fi 7) support - Wireless Ethernet Dispatch (WED) reset support - switch to using page pool allocator - RealTek WiFi (rtw89): - support new version of Bluetooth co-existance - Mobile: - rmnet: support TX aggregation" * tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1872 commits) page_pool: add a comment explaining the fragment counter usage net: ethtool: fix __ethtool_dev_mm_supported() implementation ethtool: pse-pd: Fix double word in comments xsk: add linux/vmalloc.h to xsk.c sefltests: netdevsim: wait for devlink instance after netns removal selftest: fib_tests: Always cleanup before exit net/mlx5e: Align IPsec ASO result memory to be as required by hardware net/mlx5e: TC, Set CT miss to the specific ct action instance net/mlx5e: Rename CHAIN_TO_REG to MAPPED_OBJ_TO_REG net/mlx5: Refactor tc miss handling to a single function net/mlx5: Kconfig: Make tc offload depend on tc skb extension net/sched: flower: Support hardware miss to tc action net/sched: flower: Move filter handle initialization earlier net/sched: cls_api: Support hardware miss to tc action net/sched: Rename user cookie and act cookie sfc: fix builds without CONFIG_RTC_LIB sfc: clean up some inconsistent indentings net/mlx4_en: Introduce flexible array to silence overflow warning net: lan966x: Fix possible deadlock inside PTP net/ulp: Remove redundant ->clone() test in inet_clone_ulp(). ...
Diffstat (limited to 'Documentation/hwmon/submitting-patches.rst')
-rw-r--r--Documentation/hwmon/submitting-patches.rst149
1 files changed, 149 insertions, 0 deletions
diff --git a/Documentation/hwmon/submitting-patches.rst b/Documentation/hwmon/submitting-patches.rst
new file mode 100644
index 000000000..d953ee763
--- /dev/null
+++ b/Documentation/hwmon/submitting-patches.rst
@@ -0,0 +1,149 @@
+How to Get Your Patch Accepted Into the Hwmon Subsystem
+=======================================================
+
+This text is a collection of suggestions for people writing patches or
+drivers for the hwmon subsystem. Following these suggestions will greatly
+increase the chances of your change being accepted.
+
+
+1. General
+----------
+
+* It should be unnecessary to mention, but please read and follow:
+
+ - Documentation/process/submit-checklist.rst
+ - Documentation/process/submitting-patches.rst
+ - Documentation/process/coding-style.rst
+
+* Please run your patch through 'checkpatch --strict'. There should be no
+ errors, no warnings, and few if any check messages. If there are any
+ messages, please be prepared to explain.
+
+* Please use the standard multi-line comment style. Do not mix C and C++
+ style comments in a single driver (with the exception of the SPDX license
+ identifier).
+
+* If your patch generates checkpatch errors, warnings, or check messages,
+ please refrain from explanations such as "I prefer that coding style".
+ Keep in mind that each unnecessary message helps hiding a real problem,
+ and a consistent coding style makes it easier for others to understand
+ and review the code.
+
+* Please test your patch thoroughly. We are not your test group.
+ Sometimes a patch can not or not completely be tested because of missing
+ hardware. In such cases, you should test-build the code on at least one
+ architecture. If run-time testing was not achieved, it should be written
+ explicitly below the patch header.
+
+* If your patch (or the driver) is affected by configuration options such as
+ CONFIG_SMP, make sure it compiles for all configuration variants.
+
+
+2. Adding functionality to existing drivers
+-------------------------------------------
+
+* Make sure the documentation in Documentation/hwmon/<driver_name>.rst is up to
+ date.
+
+* Make sure the information in Kconfig is up to date.
+
+* If the added functionality requires some cleanup or structural changes, split
+ your patch into a cleanup part and the actual addition. This makes it easier
+ to review your changes, and to bisect any resulting problems.
+
+* Never mix bug fixes, cleanup, and functional enhancements in a single patch.
+
+
+3. New drivers
+--------------
+
+* Running your patch or driver file(s) through checkpatch does not mean its
+ formatting is clean. If unsure about formatting in your new driver, run it
+ through Lindent. Lindent is not perfect, and you may have to do some minor
+ cleanup, but it is a good start.
+
+* Consider adding yourself to MAINTAINERS.
+
+* Document the driver in Documentation/hwmon/<driver_name>.rst.
+
+* Add the driver to Kconfig and Makefile in alphabetical order.
+
+* Make sure that all dependencies are listed in Kconfig.
+
+* Please list include files in alphabetic order.
+
+* Please align continuation lines with '(' on the previous line.
+
+* Avoid forward declarations if you can. Rearrange the code if necessary.
+
+* Avoid macros to generate groups of sensor attributes. It not only confuses
+ checkpatch, but also makes it more difficult to review the code.
+
+* Avoid calculations in macros and macro-generated functions. While such macros
+ may save a line or so in the source, it obfuscates the code and makes code
+ review more difficult. It may also result in code which is more complicated
+ than necessary. Use inline functions or just regular functions instead.
+
+* Limit the number of kernel log messages. In general, your driver should not
+ generate an error message just because a runtime operation failed. Report
+ errors to user space instead, using an appropriate error code. Keep in mind
+ that kernel error log messages not only fill up the kernel log, but also are
+ printed synchronously, most likely with interrupt disabled, often to a serial
+ console. Excessive logging can seriously affect system performance.
+
+* Use devres functions whenever possible to allocate resources. For rationale
+ and supported functions, please see Documentation/driver-api/driver-model/devres.rst.
+ If a function is not supported by devres, consider using devm_add_action().
+
+* If the driver has a detect function, make sure it is silent. Debug messages
+ and messages printed after a successful detection are acceptable, but it
+ must not print messages such as "Chip XXX not found/supported".
+
+ Keep in mind that the detect function will run for all drivers supporting an
+ address if a chip is detected on that address. Unnecessary messages will just
+ pollute the kernel log and not provide any value.
+
+* Provide a detect function if and only if a chip can be detected reliably.
+
+* Only the following I2C addresses shall be probed: 0x18-0x1f, 0x28-0x2f,
+ 0x48-0x4f, 0x58, 0x5c, 0x73 and 0x77. Probing other addresses is strongly
+ discouraged as it is known to cause trouble with other (non-hwmon) I2C
+ chips. If your chip lives at an address which can't be probed then the
+ device will have to be instantiated explicitly (which is always better
+ anyway.)
+
+* Avoid writing to chip registers in the detect function. If you have to write,
+ only do it after you have already gathered enough data to be certain that the
+ detection is going to be successful.
+
+ Keep in mind that the chip might not be what your driver believes it is, and
+ writing to it might cause a bad misconfiguration.
+
+* Make sure there are no race conditions in the probe function. Specifically,
+ completely initialize your chip and your driver first, then register with
+ the hwmon subsystem.
+
+* Use devm_hwmon_device_register_with_info() or, if your driver needs a remove
+ function, hwmon_device_register_with_info() to register your driver with the
+ hwmon subsystem. Try using devm_add_action() instead of a remove function if
+ possible. Do not use hwmon_device_register().
+
+* Your driver should be buildable as module. If not, please be prepared to
+ explain why it has to be built into the kernel.
+
+* Do not provide support for deprecated sysfs attributes.
+
+* Do not create non-standard attributes unless really needed. If you have to use
+ non-standard attributes, or you believe you do, discuss it on the mailing list
+ first. Either case, provide a detailed explanation why you need the
+ non-standard attribute(s).
+ Standard attributes are specified in Documentation/hwmon/sysfs-interface.rst.
+
+* When deciding which sysfs attributes to support, look at the chip's
+ capabilities. While we do not expect your driver to support everything the
+ chip may offer, it should at least support all limits and alarms.
+
+* Last but not least, please check if a driver for your chip already exists
+ before starting to write a new driver. Especially for temperature sensors,
+ new chips are often variants of previously released chips. In some cases,
+ a presumably new chip may simply have been relabeled.