SG_SET_TIMEOUT 0x2201.  Assumes 3rd argument points to an int containing the new timeout value for this file descriptor. The unit is a "jiffy". Packets that are already "in flight" will not be affected. The default value is set on open() and is SG_DEFAULT_TIMEOUT (defined in sg.h). This default is currently 1 minute and may not be long enough for formats. Negative values will yield an EIO error. This ioctl() is not relevant to the sg version 3 driver because timeouts are specified explicitly for each command in the sg_io_hdr structure. Only when the sg_header structure is used is the timeout inherited from this value (help on a per file descriptor basis).