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author | 2023-02-21 18:24:12 -0800 | |
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committer | 2023-02-21 18:24:12 -0800 | |
commit | 5b7c4cabbb65f5c469464da6c5f614cbd7f730f2 (patch) | |
tree | cc5c2d0a898769fd59549594fedb3ee6f84e59a0 /Documentation/userspace-api/media/v4l/selection-api-configuration.rst | |
download | linux-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/userspace-api/media/v4l/selection-api-configuration.rst')
-rw-r--r-- | Documentation/userspace-api/media/v4l/selection-api-configuration.rst | 137 |
1 files changed, 137 insertions, 0 deletions
diff --git a/Documentation/userspace-api/media/v4l/selection-api-configuration.rst b/Documentation/userspace-api/media/v4l/selection-api-configuration.rst new file mode 100644 index 000000000..fee49bf1a --- /dev/null +++ b/Documentation/userspace-api/media/v4l/selection-api-configuration.rst @@ -0,0 +1,137 @@ +.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later + +************* +Configuration +************* + +Applications can use the :ref:`selection API <VIDIOC_G_SELECTION>` to +select an area in a video signal or a buffer, and to query for default +settings and hardware limits. + +Video hardware can have various cropping, composing and scaling +limitations. It may only scale up or down, support only discrete scaling +factors, or have different scaling abilities in the horizontal and +vertical directions. Also it may not support scaling at all. At the same +time the cropping/composing rectangles may have to be aligned, and both +the source and the sink may have arbitrary upper and lower size limits. +Therefore, as usual, drivers are expected to adjust the requested +parameters and return the actual values selected. An application can +control the rounding behaviour using +:ref:`constraint flags <v4l2-selection-flags>`. + + +Configuration of video capture +============================== + +See figure :ref:`sel-targets-capture` for examples of the selection +targets available for a video capture device. It is recommended to +configure the cropping targets before to the composing targets. + +The range of coordinates of the top left corner, width and height of +areas that can be sampled is given by the ``V4L2_SEL_TGT_CROP_BOUNDS`` +target. It is recommended for the driver developers to put the top/left +corner at position ``(0,0)``. The rectangle's coordinates are expressed +in pixels. + +The top left corner, width and height of the source rectangle, that is +the area actually sampled, is given by the ``V4L2_SEL_TGT_CROP`` target. +It uses the same coordinate system as ``V4L2_SEL_TGT_CROP_BOUNDS``. The +active cropping area must lie completely inside the capture boundaries. +The driver may further adjust the requested size and/or position +according to hardware limitations. + +Each capture device has a default source rectangle, given by the +``V4L2_SEL_TGT_CROP_DEFAULT`` target. This rectangle shall cover what the +driver writer considers the complete picture. Drivers shall set the +active crop rectangle to the default when the driver is first loaded, +but not later. + +The composing targets refer to a memory buffer. The limits of composing +coordinates are obtained using ``V4L2_SEL_TGT_COMPOSE_BOUNDS``. All +coordinates are expressed in pixels. The rectangle's top/left corner +must be located at position ``(0,0)``. The width and height are equal to +the image size set by :ref:`VIDIOC_S_FMT <VIDIOC_G_FMT>`. + +The part of a buffer into which the image is inserted by the hardware is +controlled by the ``V4L2_SEL_TGT_COMPOSE`` target. The rectangle's +coordinates are also expressed in the same coordinate system as the +bounds rectangle. The composing rectangle must lie completely inside +bounds rectangle. The driver must adjust the composing rectangle to fit +to the bounding limits. Moreover, the driver can perform other +adjustments according to hardware limitations. The application can +control rounding behaviour using +:ref:`constraint flags <v4l2-selection-flags>`. + +For capture devices the default composing rectangle is queried using +``V4L2_SEL_TGT_COMPOSE_DEFAULT``. It is usually equal to the bounding +rectangle. + +The part of a buffer that is modified by the hardware is given by +``V4L2_SEL_TGT_COMPOSE_PADDED``. It contains all pixels defined using +``V4L2_SEL_TGT_COMPOSE`` plus all padding data modified by hardware +during insertion process. All pixels outside this rectangle *must not* +be changed by the hardware. The content of pixels that lie inside the +padded area but outside active area is undefined. The application can +use the padded and active rectangles to detect where the rubbish pixels +are located and remove them if needed. + + +Configuration of video output +============================= + +For output devices targets and ioctls are used similarly to the video +capture case. The *composing* rectangle refers to the insertion of an +image into a video signal. The cropping rectangles refer to a memory +buffer. It is recommended to configure the composing targets before to +the cropping targets. + +The cropping targets refer to the memory buffer that contains an image +to be inserted into a video signal or graphical screen. The limits of +cropping coordinates are obtained using ``V4L2_SEL_TGT_CROP_BOUNDS``. +All coordinates are expressed in pixels. The top/left corner is always +point ``(0,0)``. The width and height is equal to the image size +specified using :ref:`VIDIOC_S_FMT <VIDIOC_G_FMT>` ioctl. + +The top left corner, width and height of the source rectangle, that is +the area from which image date are processed by the hardware, is given +by the ``V4L2_SEL_TGT_CROP``. Its coordinates are expressed in the +same coordinate system as the bounds rectangle. The active cropping area +must lie completely inside the crop boundaries and the driver may +further adjust the requested size and/or position according to hardware +limitations. + +For output devices the default cropping rectangle is queried using +``V4L2_SEL_TGT_CROP_DEFAULT``. It is usually equal to the bounding +rectangle. + +The part of a video signal or graphics display where the image is +inserted by the hardware is controlled by ``V4L2_SEL_TGT_COMPOSE`` +target. The rectangle's coordinates are expressed in pixels. The +composing rectangle must lie completely inside the bounds rectangle. The +driver must adjust the area to fit to the bounding limits. Moreover, the +driver can perform other adjustments according to hardware limitations. + +The device has a default composing rectangle, given by the +``V4L2_SEL_TGT_COMPOSE_DEFAULT`` target. This rectangle shall cover what +the driver writer considers the complete picture. It is recommended for +the driver developers to put the top/left corner at position ``(0,0)``. +Drivers shall set the active composing rectangle to the default one when +the driver is first loaded. + +The devices may introduce additional content to video signal other than +an image from memory buffers. It includes borders around an image. +However, such a padded area is driver-dependent feature not covered by +this document. Driver developers are encouraged to keep padded rectangle +equal to active one. The padded target is accessed by the +``V4L2_SEL_TGT_COMPOSE_PADDED`` identifier. It must contain all pixels +from the ``V4L2_SEL_TGT_COMPOSE`` target. + + +Scaling control +=============== + +An application can detect if scaling is performed by comparing the width +and the height of rectangles obtained using ``V4L2_SEL_TGT_CROP`` and +``V4L2_SEL_TGT_COMPOSE`` targets. If these are not equal then the +scaling is applied. The application can compute the scaling ratios using +these values. |