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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/driver-api/media/drivers/sh_mobile_ceu_camera.rst
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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(). ...
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diff --git a/Documentation/driver-api/media/drivers/sh_mobile_ceu_camera.rst b/Documentation/driver-api/media/drivers/sh_mobile_ceu_camera.rst
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+.. SPDX-License-Identifier: GPL-2.0
+
+Cropping and Scaling algorithm, used in the sh_mobile_ceu_camera driver
+=======================================================================
+
+Author: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
+
+Terminology
+-----------
+
+sensor scales: horizontal and vertical scales, configured by the sensor driver
+host scales: -"- host driver
+combined scales: sensor_scale * host_scale
+
+
+Generic scaling / cropping scheme
+---------------------------------
+
+.. code-block:: none
+
+ -1--
+ |
+ -2-- -\
+ | --\
+ | --\
+ +-5-- . -- -3-- -\
+ | `... -\
+ | `... -4-- . - -7..
+ | `.
+ | `. .6--
+ |
+ | . .6'-
+ | .´
+ | ... -4'- .´
+ | ...´ - -7'.
+ +-5'- .´ -/
+ | -- -3'- -/
+ | --/
+ | --/
+ -2'- -/
+ |
+ |
+ -1'-
+
+In the above chart minuses and slashes represent "real" data amounts, points and
+accents represent "useful" data, basically, CEU scaled and cropped output,
+mapped back onto the client's source plane.
+
+Such a configuration can be produced by user requests:
+
+S_CROP(left / top = (5) - (1), width / height = (5') - (5))
+S_FMT(width / height = (6') - (6))
+
+Here:
+
+(1) to (1') - whole max width or height
+(1) to (2) - sensor cropped left or top
+(2) to (2') - sensor cropped width or height
+(3) to (3') - sensor scale
+(3) to (4) - CEU cropped left or top
+(4) to (4') - CEU cropped width or height
+(5) to (5') - reverse sensor scale applied to CEU cropped width or height
+(2) to (5) - reverse sensor scale applied to CEU cropped left or top
+(6) to (6') - CEU scale - user window
+
+
+S_FMT
+-----
+
+Do not touch input rectangle - it is already optimal.
+
+1. Calculate current sensor scales:
+
+ scale_s = ((2') - (2)) / ((3') - (3))
+
+2. Calculate "effective" input crop (sensor subwindow) - CEU crop scaled back at
+current sensor scales onto input window - this is user S_CROP:
+
+ width_u = (5') - (5) = ((4') - (4)) * scale_s
+
+3. Calculate new combined scales from "effective" input window to requested user
+window:
+
+ scale_comb = width_u / ((6') - (6))
+
+4. Calculate sensor output window by applying combined scales to real input
+window:
+
+ width_s_out = ((7') - (7)) = ((2') - (2)) / scale_comb
+
+5. Apply iterative sensor S_FMT for sensor output window.
+
+ subdev->video_ops->s_fmt(.width = width_s_out)
+
+6. Retrieve sensor output window (g_fmt)
+
+7. Calculate new sensor scales:
+
+ scale_s_new = ((3')_new - (3)_new) / ((2') - (2))
+
+8. Calculate new CEU crop - apply sensor scales to previously calculated
+"effective" crop:
+
+ width_ceu = (4')_new - (4)_new = width_u / scale_s_new
+ left_ceu = (4)_new - (3)_new = ((5) - (2)) / scale_s_new
+
+9. Use CEU cropping to crop to the new window:
+
+ ceu_crop(.width = width_ceu, .left = left_ceu)
+
+10. Use CEU scaling to scale to the requested user window:
+
+ scale_ceu = width_ceu / width
+
+
+S_CROP
+------
+
+The :ref:`V4L2 crop API <crop-scale>` says:
+
+"...specification does not define an origin or units. However by convention
+drivers should horizontally count unscaled samples relative to 0H."
+
+We choose to follow the advise and interpret cropping units as client input
+pixels.
+
+Cropping is performed in the following 6 steps:
+
+1. Request exactly user rectangle from the sensor.
+
+2. If smaller - iterate until a larger one is obtained. Result: sensor cropped
+ to 2 : 2', target crop 5 : 5', current output format 6' - 6.
+
+3. In the previous step the sensor has tried to preserve its output frame as
+ good as possible, but it could have changed. Retrieve it again.
+
+4. Sensor scaled to 3 : 3'. Sensor's scale is (2' - 2) / (3' - 3). Calculate
+ intermediate window: 4' - 4 = (5' - 5) * (3' - 3) / (2' - 2)
+
+5. Calculate and apply host scale = (6' - 6) / (4' - 4)
+
+6. Calculate and apply host crop: 6 - 7 = (5 - 2) * (6' - 6) / (5' - 5)