77 lines
1.5 KiB
C
77 lines
1.5 KiB
C
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/* usbreset -- send a USB port reset to a USB device */
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/*
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http://marc.info/?l=linux-usb-users&m=116827193506484&w=2
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and needs mounted usbfs filesystem
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sudo mount -t usbfs none /proc/bus/usb
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There is a way to suspend a USB device. In order to use it,
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you must have a kernel with CONFIG_PM_SYSFS_DEPRECATED turned on. To
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suspend a device, do (as root):
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echo -n 2 >/sys/bus/usb/devices/.../power/state
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where the "..." is the ID for your device. To unsuspend, do the same
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thing but with a "0" instead of the "2" above.
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Note that this mechanism is slated to be removed from the kernel within
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the next year. Hopefully some other mechanism will take its place.
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> To reset a
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> device?
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Here's a program to do it. You invoke it as either
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usbreset /proc/bus/usb/BBB/DDD
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or
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usbreset /dev/usbB.D
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depending on how your system is set up, where BBB and DDD are the bus and
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device address numbers.
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Alan Stern
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*/
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#include <stdio.h>
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#include <unistd.h>
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#include <fcntl.h>
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#include <errno.h>
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#include <sys/ioctl.h>
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#include <linux/usbdevice_fs.h>
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int main(int argc, char **argv)
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{
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const char *filename;
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int fd;
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int rc;
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if (argc != 2) {
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fprintf(stderr, "Usage: usbreset device-filename\n");
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return 1;
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}
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filename = argv[1];
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fd = open(filename, O_WRONLY);
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if (fd < 0) {
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perror("Error opening output file");
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return 1;
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}
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printf("Resetting USB device %s\n", filename);
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rc = ioctl(fd, USBDEVFS_RESET, 0);
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if (rc < 0) {
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perror("Error in ioctl");
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return 1;
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}
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printf("Reset successful\n");
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close(fd);
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return 0;
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}
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