1.. SPDX-License-Identifier: GPL-2.0
2
3========================
4tcm_qla2xxx Driver Notes
5========================
6
7tcm_qla2xxx jam_host attribute
8------------------------------
9There is now a new module endpoint attribute called jam_host
10attribute::
11
12	jam_host: boolean=0/1
13
14This attribute and accompanying code is only included if the
15Kconfig parameter TCM_QLA2XXX_DEBUG is set to Y
16
17By default this jammer code and functionality is disabled
18
19Use this attribute to control the discarding of SCSI commands to a
20selected host.
21
22This may be useful for testing error handling and simulating slow drain
23and other fabric issues.
24
25Setting a boolean of 1 for the jam_host attribute for a particular host
26will discard the commands for that host.
27
28Reset back to 0 to stop the jamming.
29
30Enable host 4 to be jammed::
31
32  echo 1 > /sys/kernel/config/target/qla2xxx/21:00:00:24:ff:27:8f:ae/tpgt_1/attrib/jam_host
33
34Disable jamming on host 4::
35
36  echo 0 > /sys/kernel/config/target/qla2xxx/21:00:00:24:ff:27:8f:ae/tpgt_1/attrib/jam_host
37