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POwhy does ioctl return "bad address"
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2013-04-02T16:50:50.547
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2013-05-10T13:54:12.020
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I use the the code below to output data from SPI port of an embedded board (olimex imx233-micro -- it is not a board specific question). When I run the code <code>ioctl</code> return "bad address". I am modifying the code on <a href="http://twilight.ponies.cz/spi-test.c" rel="nofollow">http://twilight.ponies.cz/spi-test.c</a> which works fine. Could anyone tell me what am I doing wrong? <pre><code>root@ubuntu:/home# gcc test.c -o test test.c:20: warning: conflicting types for ‘msg_send’ test.c:16: note: previous implicit declaration of ‘msg_send’ was here root@ubuntu:/home# ./test errno:Bad address - cannot send SPI message root@ubuntu:/home# uname -a Linux ubuntu 3.7.1 #2 Sun Mar 17 03:49:39 CET 2013 armv5tejl GNU/Linux </code></pre> Code: <pre><code>//test.c #include <stdint.h> #include <unistd.h> #include <stdio.h> #include <stdlib.h> #include <string.h> #include <getopt.h> #include <fcntl.h> #include <sys/ioctl.h> #include <linux/types.h> #include <linux/spi/spidev.h> #include <errno.h> static uint16_t delay; int main(int argc,char *argv[]){ msg_send(254); //the message that I want to send decimal "254" return 0; } void msg_send(int msg){ int fd; int ret = 0; fd = open("/dev/spidev32766.1", O_RDWR); //ls /dev outputs spidev32766.1 if(fd < 0){ fprintf(stderr, "errno:%s - FD could be not opened\n ", strerror(errno)); exit(1); } struct spi_ioc_transfer tr = { .len = 1, .delay_usecs = delay, .speed_hz = 500000, //500 kHz .bits_per_word = 8, .tx_buf = msg, .rx_buf = 0, //half duplex }; ret = ioctl(fd, SPI_IOC_MESSAGE(1), &tr); if (ret <1 ){ fprintf(stderr, "errno:%s - cannot send SPI message\n ", strerror(errno)); } close(fd); } </code></pre> Thank you!
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<c><linux><posix><ioctl>
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why does ioctl return "bad address"
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1. USsven
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