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(). ... --- .../userspace-api/media/cec/cec-ioc-receive.rst | 385 +++++++++++++++++++++ 1 file changed, 385 insertions(+) create mode 100644 Documentation/userspace-api/media/cec/cec-ioc-receive.rst (limited to 'Documentation/userspace-api/media/cec/cec-ioc-receive.rst') diff --git a/Documentation/userspace-api/media/cec/cec-ioc-receive.rst b/Documentation/userspace-api/media/cec/cec-ioc-receive.rst new file mode 100644 index 000000000..364938ad3 --- /dev/null +++ b/Documentation/userspace-api/media/cec/cec-ioc-receive.rst @@ -0,0 +1,385 @@ +.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later +.. c:namespace:: CEC + +.. _CEC_TRANSMIT: +.. _CEC_RECEIVE: + +*********************************** +ioctls CEC_RECEIVE and CEC_TRANSMIT +*********************************** + +Name +==== + +CEC_RECEIVE, CEC_TRANSMIT - Receive or transmit a CEC message + +Synopsis +======== + +.. c:macro:: CEC_RECEIVE + +``int ioctl(int fd, CEC_RECEIVE, struct cec_msg *argp)`` + +.. c:macro:: CEC_TRANSMIT + +``int ioctl(int fd, CEC_TRANSMIT, struct cec_msg *argp)`` + +Arguments +========= + +``fd`` + File descriptor returned by :c:func:`open()`. + +``argp`` + Pointer to struct cec_msg. + +Description +=========== + +To receive a CEC message the application has to fill in the +``timeout`` field of struct :c:type:`cec_msg` and pass it to +:ref:`ioctl CEC_RECEIVE `. +If the file descriptor is in non-blocking mode and there are no received +messages pending, then it will return -1 and set errno to the ``EAGAIN`` +error code. If the file descriptor is in blocking mode and ``timeout`` +is non-zero and no message arrived within ``timeout`` milliseconds, then +it will return -1 and set errno to the ``ETIMEDOUT`` error code. + +A received message can be: + +1. a message received from another CEC device (the ``sequence`` field will + be 0, ``tx_status`` will be 0 and ``rx_status`` will be non-zero). +2. the transmit result of an earlier non-blocking transmit (the ``sequence`` + field will be non-zero, ``tx_status`` will be non-zero and ``rx_status`` + will be 0). +3. the reply to an earlier non-blocking transmit (the ``sequence`` field will + be non-zero, ``tx_status`` will be 0 and ``rx_status`` will be non-zero). + +To send a CEC message the application has to fill in the struct +:c:type:`cec_msg` and pass it to :ref:`ioctl CEC_TRANSMIT `. +The :ref:`ioctl CEC_TRANSMIT ` is only available if +``CEC_CAP_TRANSMIT`` is set. If there is no more room in the transmit +queue, then it will return -1 and set errno to the ``EBUSY`` error code. +The transmit queue has enough room for 18 messages (about 1 second worth +of 2-byte messages). Note that the CEC kernel framework will also reply +to core messages (see :ref:`cec-core-processing`), so it is not a good +idea to fully fill up the transmit queue. + +If the file descriptor is in non-blocking mode then the transmit will +return 0 and the result of the transmit will be available via +:ref:`ioctl CEC_RECEIVE ` once the transmit has finished. +If a non-blocking transmit also specified waiting for a reply, then +the reply will arrive in a later message. The ``sequence`` field can +be used to associate both transmit results and replies with the original +transmit. + +Normally calling :ref:`ioctl CEC_TRANSMIT ` when the physical +address is invalid (due to e.g. a disconnect) will return ``ENONET``. + +However, the CEC specification allows sending messages from 'Unregistered' to +'TV' when the physical address is invalid since some TVs pull the hotplug detect +pin of the HDMI connector low when they go into standby, or when switching to +another input. + +When the hotplug detect pin goes low the EDID disappears, and thus the +physical address, but the cable is still connected and CEC still works. +In order to detect/wake up the device it is allowed to send poll and 'Image/Text +View On' messages from initiator 0xf ('Unregistered') to destination 0 ('TV'). + +.. tabularcolumns:: |p{1.0cm}|p{3.5cm}|p{12.8cm}| + +.. c:type:: cec_msg + +.. cssclass:: longtable + +.. flat-table:: struct cec_msg + :header-rows: 0 + :stub-columns: 0 + :widths: 1 1 16 + + * - __u64 + - ``tx_ts`` + - Timestamp in ns of when the last byte of the message was transmitted. + The timestamp has been taken from the ``CLOCK_MONOTONIC`` clock. To access + the same clock from userspace use :c:func:`clock_gettime`. + * - __u64 + - ``rx_ts`` + - Timestamp in ns of when the last byte of the message was received. + The timestamp has been taken from the ``CLOCK_MONOTONIC`` clock. To access + the same clock from userspace use :c:func:`clock_gettime`. + * - __u32 + - ``len`` + - The length of the message. For :ref:`ioctl CEC_TRANSMIT ` this is filled in + by the application. The driver will fill this in for + :ref:`ioctl CEC_RECEIVE `. For :ref:`ioctl CEC_TRANSMIT ` it will be + filled in by the driver with the length of the reply message if ``reply`` was set. + * - __u32 + - ``timeout`` + - The timeout in milliseconds. This is the time the device will wait + for a message to be received before timing out. If it is set to 0, + then it will wait indefinitely when it is called by :ref:`ioctl CEC_RECEIVE `. + If it is 0 and it is called by :ref:`ioctl CEC_TRANSMIT `, + then it will be replaced by 1000 if the ``reply`` is non-zero or + ignored if ``reply`` is 0. + * - __u32 + - ``sequence`` + - A non-zero sequence number is automatically assigned by the CEC framework + for all transmitted messages. It is used by the CEC framework when it queues + the transmit result for a non-blocking transmit. This allows the application + to associate the received message with the original transmit. + + In addition, if a non-blocking transmit will wait for a reply (ii.e. ``timeout`` + was not 0), then the ``sequence`` field of the reply will be set to the sequence + value of the original transmit. This allows the application to associate the + received message with the original transmit. + * - __u32 + - ``flags`` + - Flags. See :ref:`cec-msg-flags` for a list of available flags. + * - __u8 + - ``msg[16]`` + - The message payload. For :ref:`ioctl CEC_TRANSMIT ` this is filled in by the + application. The driver will fill this in for :ref:`ioctl CEC_RECEIVE `. + For :ref:`ioctl CEC_TRANSMIT ` it will be filled in by the driver with + the payload of the reply message if ``timeout`` was set. + * - __u8 + - ``reply`` + - Wait until this message is replied. If ``reply`` is 0 and the + ``timeout`` is 0, then don't wait for a reply but return after + transmitting the message. Ignored by :ref:`ioctl CEC_RECEIVE `. + The case where ``reply`` is 0 (this is the opcode for the Feature Abort + message) and ``timeout`` is non-zero is specifically allowed to make it + possible to send a message and wait up to ``timeout`` milliseconds for a + Feature Abort reply. In this case ``rx_status`` will either be set + to :ref:`CEC_RX_STATUS_TIMEOUT ` or + :ref:`CEC_RX_STATUS_FEATURE_ABORT `. + + If the transmitter message is ``CEC_MSG_INITIATE_ARC`` then the ``reply`` + values ``CEC_MSG_REPORT_ARC_INITIATED`` and ``CEC_MSG_REPORT_ARC_TERMINATED`` + are processed differently: either value will match both possible replies. + The reason is that the ``CEC_MSG_INITIATE_ARC`` message is the only CEC + message that has two possible replies other than Feature Abort. The + ``reply`` field will be updated with the actual reply so that it is + synchronized with the contents of the received message. + * - __u8 + - ``rx_status`` + - The status bits of the received message. See + :ref:`cec-rx-status` for the possible status values. + * - __u8 + - ``tx_status`` + - The status bits of the transmitted message. See + :ref:`cec-tx-status` for the possible status values. + When calling :ref:`ioctl CEC_TRANSMIT ` in non-blocking mode, + this field will be 0 if the transmit started, or non-0 if the transmit + result is known immediately. The latter would be the case when attempting + to transmit a Poll message to yourself. That results in a + :ref:`CEC_TX_STATUS_NACK ` without ever actually + transmitting the Poll message. + * - __u8 + - ``tx_arb_lost_cnt`` + - A counter of the number of transmit attempts that resulted in the + Arbitration Lost error. This is only set if the hardware supports + this, otherwise it is always 0. This counter is only valid if the + :ref:`CEC_TX_STATUS_ARB_LOST ` status bit is set. + * - __u8 + - ``tx_nack_cnt`` + - A counter of the number of transmit attempts that resulted in the + Not Acknowledged error. This is only set if the hardware supports + this, otherwise it is always 0. This counter is only valid if the + :ref:`CEC_TX_STATUS_NACK ` status bit is set. + * - __u8 + - ``tx_low_drive_cnt`` + - A counter of the number of transmit attempts that resulted in the + Arbitration Lost error. This is only set if the hardware supports + this, otherwise it is always 0. This counter is only valid if the + :ref:`CEC_TX_STATUS_LOW_DRIVE ` status bit is set. + * - __u8 + - ``tx_error_cnt`` + - A counter of the number of transmit errors other than Arbitration + Lost or Not Acknowledged. This is only set if the hardware + supports this, otherwise it is always 0. This counter is only + valid if the :ref:`CEC_TX_STATUS_ERROR ` status bit is set. + +.. tabularcolumns:: |p{6.2cm}|p{1.0cm}|p{10.1cm}| + +.. _cec-msg-flags: + +.. flat-table:: Flags for struct cec_msg + :header-rows: 0 + :stub-columns: 0 + :widths: 3 1 4 + + * .. _`CEC-MSG-FL-REPLY-TO-FOLLOWERS`: + + - ``CEC_MSG_FL_REPLY_TO_FOLLOWERS`` + - 1 + - If a CEC transmit expects a reply, then by default that reply is only sent to + the filehandle that called :ref:`ioctl CEC_TRANSMIT `. If this + flag is set, then the reply is also sent to all followers, if any. If the + filehandle that called :ref:`ioctl CEC_TRANSMIT ` is also a + follower, then that filehandle will receive the reply twice: once as the + result of the :ref:`ioctl CEC_TRANSMIT `, and once via + :ref:`ioctl CEC_RECEIVE `. + + * .. _`CEC-MSG-FL-RAW`: + + - ``CEC_MSG_FL_RAW`` + - 2 + - Normally CEC messages are validated before transmitting them. If this + flag is set when :ref:`ioctl CEC_TRANSMIT ` is called, + then no validation takes place and the message is transmitted as-is. + This is useful when debugging CEC issues. + This flag is only allowed if the process has the ``CAP_SYS_RAWIO`` + capability. If that is not set, then the ``EPERM`` error code is + returned. + +.. tabularcolumns:: |p{5.6cm}|p{0.9cm}|p{10.8cm}| + +.. _cec-tx-status: + +.. flat-table:: CEC Transmit Status + :header-rows: 0 + :stub-columns: 0 + :widths: 3 1 16 + + * .. _`CEC-TX-STATUS-OK`: + + - ``CEC_TX_STATUS_OK`` + - 0x01 + - The message was transmitted successfully. This is mutually + exclusive with :ref:`CEC_TX_STATUS_MAX_RETRIES `. + Other bits can still be set if earlier attempts met with failure before + the transmit was eventually successful. + * .. _`CEC-TX-STATUS-ARB-LOST`: + + - ``CEC_TX_STATUS_ARB_LOST`` + - 0x02 + - CEC line arbitration was lost, i.e. another transmit started at the + same time with a higher priority. Optional status, not all hardware + can detect this error condition. + * .. _`CEC-TX-STATUS-NACK`: + + - ``CEC_TX_STATUS_NACK`` + - 0x04 + - Message was not acknowledged. Note that some hardware cannot tell apart + a 'Not Acknowledged' status from other error conditions, i.e. the result + of a transmit is just OK or FAIL. In that case this status will be + returned when the transmit failed. + * .. _`CEC-TX-STATUS-LOW-DRIVE`: + + - ``CEC_TX_STATUS_LOW_DRIVE`` + - 0x08 + - Low drive was detected on the CEC bus. This indicates that a + follower detected an error on the bus and requests a + retransmission. Optional status, not all hardware can detect this + error condition. + * .. _`CEC-TX-STATUS-ERROR`: + + - ``CEC_TX_STATUS_ERROR`` + - 0x10 + - Some error occurred. This is used for any errors that do not fit + ``CEC_TX_STATUS_ARB_LOST`` or ``CEC_TX_STATUS_LOW_DRIVE``, either because + the hardware could not tell which error occurred, or because the hardware + tested for other conditions besides those two. Optional status. + * .. _`CEC-TX-STATUS-MAX-RETRIES`: + + - ``CEC_TX_STATUS_MAX_RETRIES`` + - 0x20 + - The transmit failed after one or more retries. This status bit is + mutually exclusive with :ref:`CEC_TX_STATUS_OK `. + Other bits can still be set to explain which failures were seen. + * .. _`CEC-TX-STATUS-ABORTED`: + + - ``CEC_TX_STATUS_ABORTED`` + - 0x40 + - The transmit was aborted due to an HDMI disconnect, or the adapter + was unconfigured, or a transmit was interrupted, or the driver + returned an error when attempting to start a transmit. + * .. _`CEC-TX-STATUS-TIMEOUT`: + + - ``CEC_TX_STATUS_TIMEOUT`` + - 0x80 + - The transmit timed out. This should not normally happen and this + indicates a driver problem. + +.. tabularcolumns:: |p{5.6cm}|p{0.9cm}|p{10.8cm}| + +.. _cec-rx-status: + +.. flat-table:: CEC Receive Status + :header-rows: 0 + :stub-columns: 0 + :widths: 3 1 16 + + * .. _`CEC-RX-STATUS-OK`: + + - ``CEC_RX_STATUS_OK`` + - 0x01 + - The message was received successfully. + * .. _`CEC-RX-STATUS-TIMEOUT`: + + - ``CEC_RX_STATUS_TIMEOUT`` + - 0x02 + - The reply to an earlier transmitted message timed out. + * .. _`CEC-RX-STATUS-FEATURE-ABORT`: + + - ``CEC_RX_STATUS_FEATURE_ABORT`` + - 0x04 + - The message was received successfully but the reply was + ``CEC_MSG_FEATURE_ABORT``. This status is only set if this message + was the reply to an earlier transmitted message. + * .. _`CEC-RX-STATUS-ABORTED`: + + - ``CEC_RX_STATUS_ABORTED`` + - 0x08 + - The wait for a reply to an earlier transmitted message was aborted + because the HDMI cable was disconnected, the adapter was unconfigured + or the :ref:`CEC_TRANSMIT ` that waited for a + reply was interrupted. + + +Return Value +============ + +On success 0 is returned, on error -1 and the ``errno`` variable is set +appropriately. The generic error codes are described at the +:ref:`Generic Error Codes ` chapter. + +The :ref:`ioctl CEC_RECEIVE ` can return the following +error codes: + +EAGAIN + No messages are in the receive queue, and the filehandle is in non-blocking mode. + +ETIMEDOUT + The ``timeout`` was reached while waiting for a message. + +ERESTARTSYS + The wait for a message was interrupted (e.g. by Ctrl-C). + +The :ref:`ioctl CEC_TRANSMIT ` can return the following +error codes: + +ENOTTY + The ``CEC_CAP_TRANSMIT`` capability wasn't set, so this ioctl is not supported. + +EPERM + The CEC adapter is not configured, i.e. :ref:`ioctl CEC_ADAP_S_LOG_ADDRS ` + has never been called, or ``CEC_MSG_FL_RAW`` was used from a process that + did not have the ``CAP_SYS_RAWIO`` capability. + +ENONET + The CEC adapter is not configured, i.e. :ref:`ioctl CEC_ADAP_S_LOG_ADDRS ` + was called, but the physical address is invalid so no logical address was claimed. + An exception is made in this case for transmits from initiator 0xf ('Unregistered') + to destination 0 ('TV'). In that case the transmit will proceed as usual. + +EBUSY + Another filehandle is in exclusive follower or initiator mode, or the filehandle + is in mode ``CEC_MODE_NO_INITIATOR``. This is also returned if the transmit + queue is full. + +EINVAL + The contents of struct :c:type:`cec_msg` is invalid. + +ERESTARTSYS + The wait for a successful transmit was interrupted (e.g. by Ctrl-C). -- cgit v1.2.3