From 5b7c4cabbb65f5c469464da6c5f614cbd7f730f2 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Tue, 21 Feb 2023 18:24:12 -0800 Subject: Merge tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next 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(). ... --- Documentation/userspace-api/media/v4l/dev-osd.rst | 150 ++++++++++++++++++++++ 1 file changed, 150 insertions(+) create mode 100644 Documentation/userspace-api/media/v4l/dev-osd.rst (limited to 'Documentation/userspace-api/media/v4l/dev-osd.rst') diff --git a/Documentation/userspace-api/media/v4l/dev-osd.rst b/Documentation/userspace-api/media/v4l/dev-osd.rst new file mode 100644 index 000000000..8e4be9129 --- /dev/null +++ b/Documentation/userspace-api/media/v4l/dev-osd.rst @@ -0,0 +1,150 @@ +.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later + +.. _osd: + +****************************** +Video Output Overlay Interface +****************************** + +**Also known as On-Screen Display (OSD)** + +Some video output devices can overlay a framebuffer image onto the +outgoing video signal. Applications can set up such an overlay using +this interface, which borrows structures and ioctls of the +:ref:`Video Overlay ` interface. + +The OSD function is accessible through the same character special file +as the :ref:`Video Output ` function. + +.. note:: + + The default function of such a ``/dev/video`` device is video + capturing or output. The OSD function is only available after calling + the :ref:`VIDIOC_S_FMT ` ioctl. + + +Querying Capabilities +===================== + +Devices supporting the *Video Output Overlay* interface set the +``V4L2_CAP_VIDEO_OUTPUT_OVERLAY`` flag in the ``capabilities`` field of +struct :c:type:`v4l2_capability` returned by the +:ref:`VIDIOC_QUERYCAP` ioctl. + + +Framebuffer +=========== + +Contrary to the *Video Overlay* interface the framebuffer is normally +implemented on the TV card and not the graphics card. On Linux it is +accessible as a framebuffer device (``/dev/fbN``). Given a V4L2 device, +applications can find the corresponding framebuffer device by calling +the :ref:`VIDIOC_G_FBUF ` ioctl. It returns, amongst +other information, the physical address of the framebuffer in the +``base`` field of struct :c:type:`v4l2_framebuffer`. +The framebuffer device ioctl ``FBIOGET_FSCREENINFO`` returns the same +address in the ``smem_start`` field of struct +:c:type:`fb_fix_screeninfo`. The ``FBIOGET_FSCREENINFO`` +ioctl and struct :c:type:`fb_fix_screeninfo` are defined in +the ``linux/fb.h`` header file. + +The width and height of the framebuffer depends on the current video +standard. A V4L2 driver may reject attempts to change the video standard +(or any other ioctl which would imply a framebuffer size change) with an +``EBUSY`` error code until all applications closed the framebuffer device. + +Example: Finding a framebuffer device for OSD +--------------------------------------------- + +.. code-block:: c + + #include + + struct v4l2_framebuffer fbuf; + unsigned int i; + int fb_fd; + + if (-1 == ioctl(fd, VIDIOC_G_FBUF, &fbuf)) { + perror("VIDIOC_G_FBUF"); + exit(EXIT_FAILURE); + } + + for (i = 0; i < 30; i++) { + char dev_name[16]; + struct fb_fix_screeninfo si; + + snprintf(dev_name, sizeof(dev_name), "/dev/fb%u", i); + + fb_fd = open(dev_name, O_RDWR); + if (-1 == fb_fd) { + switch (errno) { + case ENOENT: /* no such file */ + case ENXIO: /* no driver */ + continue; + + default: + perror("open"); + exit(EXIT_FAILURE); + } + } + + if (0 == ioctl(fb_fd, FBIOGET_FSCREENINFO, &si)) { + if (si.smem_start == (unsigned long)fbuf.base) + break; + } else { + /* Apparently not a framebuffer device. */ + } + + close(fb_fd); + fb_fd = -1; + } + + /* fb_fd is the file descriptor of the framebuffer device + for the video output overlay, or -1 if no device was found. */ + + +Overlay Window and Scaling +========================== + +The overlay is controlled by source and target rectangles. The source +rectangle selects a subsection of the framebuffer image to be overlaid, +the target rectangle an area in the outgoing video signal where the +image will appear. Drivers may or may not support scaling, and arbitrary +sizes and positions of these rectangles. Further drivers may support any +(or none) of the clipping/blending methods defined for the +:ref:`Video Overlay ` interface. + +A struct :c:type:`v4l2_window` defines the size of the +source rectangle, its position in the framebuffer and the +clipping/blending method to be used for the overlay. To get the current +parameters applications set the ``type`` field of a struct +:c:type:`v4l2_format` to +``V4L2_BUF_TYPE_VIDEO_OUTPUT_OVERLAY`` and call the +:ref:`VIDIOC_G_FMT ` ioctl. The driver fills the +struct :c:type:`v4l2_window` substructure named ``win``. It is not +possible to retrieve a previously programmed clipping list or bitmap. + +To program the source rectangle applications set the ``type`` field of a +struct :c:type:`v4l2_format` to +``V4L2_BUF_TYPE_VIDEO_OUTPUT_OVERLAY``, initialize the ``win`` +substructure and call the :ref:`VIDIOC_S_FMT ` ioctl. +The driver adjusts the parameters against hardware limits and returns +the actual parameters as :ref:`VIDIOC_G_FMT ` does. Like :ref:`VIDIOC_S_FMT `, +the :ref:`VIDIOC_TRY_FMT ` ioctl can be used to learn +about driver capabilities without actually changing driver state. Unlike +:ref:`VIDIOC_S_FMT ` this also works after the overlay has been enabled. + +A struct :c:type:`v4l2_crop` defines the size and position +of the target rectangle. The scaling factor of the overlay is implied by +the width and height given in struct :c:type:`v4l2_window` +and struct :c:type:`v4l2_crop`. The cropping API applies to +*Video Output* and *Video Output Overlay* devices in the same way as to +*Video Capture* and *Video Overlay* devices, merely reversing the +direction of the data flow. For more information see :ref:`crop`. + + +Enabling Overlay +================ + +There is no V4L2 ioctl to enable or disable the overlay, however the +framebuffer interface of the driver may support the ``FBIOBLANK`` ioctl. -- cgit v1.2.3