Ioctl return -1

Author: bvua

August undefined, 2024

Web24 mrt. 2024 · 如果ioctl执行成功，它的返回值就是驱动程序中ioctl接口给的返回值，驱动程序可以通过返回值向用户程序传参。但驱动程序最好返回一个非负数，因为用户程序中的ioctl运行失败时一定会返回-1并设置全局变量errorno。 errono不同的值代表的含义如下： EBADF：fd是一个无效的文件描述符。 EFAULT：在arg是指针的前提下，argp指向一个 … WebThe name of a fullword in which the w_ioctl service stores the return code. The w_ioctl service returns Return_code only if Return_value is -1. For a list of return code values, see Return codes (errnos) in z/OS UNIX System Services Messages and Codes. The w_ioctl service returns one of the following values in the Return_code parameter:

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WebDESCRIPTION. The ioctl () function shall perform a variety of control functions on STREAMS devices. For non-STREAMS devices, the functions performed by this call are unspecified. The request argument and an optional third argument (with varying type) shall be passed to and interpreted by the appropriate part of the STREAM associated with fildes. Webioctl(file, I2C_SMBUS, struct i2c_smbus_ioctl_data *args) If possible, use the provided i2c_smbus_* methods described below instead of issuing direct ioctls. You can do plain … d-way tools sharpening

[PATCH v2 18/27] compat_ioctl: scsi: move ioctl handling into …

Web15 okt. 2024 · 1) 如果传入的非法命令， ioctl 返回错误号 -EINVAL 。 2) 内核中的驱动函数返回值都有一个默认的方法，只要是正数，内核就会傻乎乎的认为这是正确的返回，并把它传给应用层，如果是负值，内核就会认为它是错误号了。 Ioctl 里面多个不同的命令，那就要看它函数的实现来决定返回值了。打个比方，如果 ioctl 里面有一个类似 read 的函数，那 … WebNote. The tuner rxsubchans flags are reused, but the semantics are different. Video output devices are assumed to have an analog or PCM audio input with 1-3 channels. The txsubchans flags select one or more channels for modulation, together with some audio subprogram indicator, for example, a stereo pilot tone. d way travel

ioctl(2) - Linux manual page - Michael Kerrisk

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WebAnd that function > stores the return value in an "int r" variable. So the upper 32-bits > of the "long" return value are lost there. > > KVM ioctl functions should only return "int" values, so let's limit > the amount of bytes that can be requested here to INT_MAX to avoid > the problem with the truncated return value. WebIf successful, ioctl() returns a value other than -1 that depends upon the STREAMS device control function. If unsuccessful, ioctl() returns -1 and sets errno to one of the following … dwba bath collectionWeb21 okt. 2024 · CH341A USB to I2C and GPIO Linux kernel driver. The driver can be used with CH341A USB to UART/I2C/SPI adapter boards to connect I2C devices to a Linux host. Additionally, CH341A data pins that are not used for synchronous serial interfaces can be configured as GPIO pins. The driver can generate software interrupts for all input pins. d way travel earsham

"WebAt return, if no errors happen, this ioctl will return the topology_version and the total number of entities, interfaces, pads and links. Before the second call, the userspace should allocate arrays to store the graph elements that are desired, putting the pointers to them at the ptr_entities, ptr_interfaces, ptr_links and/or ptr_pads, keeping the other values … " - Ioctl return -1

Ioctl return -1

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http://www.verycomputer.com/183_fa1b6e5fb34c28d3_1.htm WebIf the CD has ANY data tracks on it, it will be returned as a data CD. If it has any XA tracks, I will return it as that. Now I could simplify this interface by combining these returns with the above, but this more clearly demonstrates the problem with the current interface. Too bad this wasn't designed to use bitmasks...

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Webout_flags flags indicating which registers are valid in_flags flags indicating which registers should be returned data_phase see below req_cmd command type to be executed out_size size of output buffer outbuf buffer of data to be transmitted to disk inbuf buffer of data to be received from disk (see [1]) ===== ===== outputs: ===== ===== io_ports[] values … WebThis ioctl command is used, for instance, by mkfs to know the size of the filesystem being created. BLKFLSBUF. Literally, “flush buffers.”. The implementation of this command is …

WebAn ioctl() request has encoded in it whether the argument is an in parameter or out parameter, and the size of the argument argp in bytes. Macros and defines used in specifying an ioctl() request are located in the file . See NOTES. RETURN … The return value is one of the CLONE_NEW* values that can be … Wij willen hier een beschrijving geven, maar de site die u nu bekijkt staat dit niet toe. Ioctl XFS Fsgeometry - ioctl(2) - Linux manual page - Michael Kerrisk IOCTL-XFS-BULKSTAT(2) System Calls Manual IOCTL-XFS-BULKSTAT(2) … Upon successful completion of this ioctl, the number of bytes successfully … This ioctl reflinks up to src_length bytes from file descriptor src_fd at offset … Ioctl XFS Getresblks - ioctl(2) - Linux manual page - Michael Kerrisk Ioctl XFS Fscounts - ioctl(2) - Linux manual page - Michael Kerrisk WebAll these transactions return -1 on failure; you can read errno to see what happened. The ‘write’ transactions return 0 on success; the ‘read’ transactions return the read value, except for read_block, which returns the number of values read. The block buffers need not be longer than 32 bytes.

Web6 apr. 2009 · 2 Answers. Sorted by: 0. The device you are calling ioctl on may include some code that checks for capabilities before performing the action you … Web5 apr. 2024 · return -1; } if (S_ISBLK(st.st_mode)) { unsigned long long bytes; if (ioctl(fd, BLKGETSIZE64, &bytes) != 0) { perror("ioctl"); return -1; } return bytes; } else if (S_ISREG(st.st_mode)) return st.st_size; return -1; } /* * Output a string of characters of len length to stdout. * We use buffered output here to be efficient,

WebThe explain_message_errno_ioctl function may be used to obtain an explanation of an error returned by the ioctl (2) system call. The least the message will contain is the value of strerror (errnum), but usually it will do much better, …

WebIf not found, return 0. * Returns pointer to dynamically allocated string. /* Set or clear auto-eject mode. */. * Stops CDROM from opening on manual eject button press. * in your bag while it's on and no CD inserted in it's drive. * Changer select. CDROM_SELECT_DISC is preferred, older kernels used. crystal for protection from negative energyWeb2 mrt. 2024 · File descriptor returned by open(). argp. Pointer to struct dmx_exportbuffer. 3.2.18.4. Description¶ This ioctl is an extension to the memory mapping I/O method. It can be used to export a buffer as a DMABUF file at any time after buffers have been allocated with the ioctl DMX_REQBUFS ioctl. To export a buffer, applications fill struct dmx ... crystal for remembering dreamshttp://www.verycomputer.com/183_fa1b6e5fb34c28d3_1.htm dwb8mis01 c$WebThe explain_message_errno_ioctl function may be used to obtain an explanation of an error returned by the ioctl(2) system call. The least the message will contain is the value of … dway vancouverWebThe SIOCTTLSCTL ioctl provides the interface for an application to query and control AT-TLS. Table 1 describes the error codes that can be returned on this ioctl, along with the conditions under which each can occur. Also included for each is an indication of whether the query data fields in the ioctl contain valid returned data. crystal for protection in carWeb5 apr. 2024 · GPUDirect Storage is currently only supported on Quadro and Tesla GPUs in p2p mode. This is shown with ‘supported’ string in gdscheck output. Also the block filesystems that GPUDirect Storage supports are ext4 with ordered mode and XFS. The linux distros tested are Ubuntu 18.02- 22.04 , Rhel 8.4 and above. crystal for pregnancy healthWeb1. V4L2_CAP_HW_FREQ_SEEK. 0x00000400. The device supports the ioctl VIDIOC_S_HW_FREQ_SEEK ioctl for hardware frequency seeking. V4L2_CAP_RDS_OUTPUT. 0x00000800. The device supports the RDS output interface. V4L2_CAP_TUNER. 0x00010000. The device has some sort of tuner to receive RF … crystal for remembering