Test if unit is ready
int scsi_test_unit_ready(struct scsi_device * sdev, int timeout, int retries, struct scsi_sense_hdr * sshdr_external);
sdev
scsi device to change the state of.
timeout
command timeout
retries
number of retries before failing
sshdr_external
Optional pointer to struct scsi_sense_hdr for returning sense. Make sure that this is cleared before passing in.
Returns zero if unsuccessful or an error if TUR failed. For removable media, UNIT_ATTENTION sets ->changed flag.