xref: /openbmc/linux/Documentation/scsi/tcm_qla2xxx.rst (revision 9a87ffc99ec8eb8d35eed7c4f816d75f5cc9662e)
1e92c45d2SMauro Carvalho Chehab.. SPDX-License-Identifier: GPL-2.0
2e92c45d2SMauro Carvalho Chehab
3e92c45d2SMauro Carvalho Chehab========================
4e92c45d2SMauro Carvalho Chehabtcm_qla2xxx Driver Notes
5e92c45d2SMauro Carvalho Chehab========================
6e92c45d2SMauro Carvalho Chehab
7e92c45d2SMauro Carvalho Chehabtcm_qla2xxx jam_host attribute
8e92c45d2SMauro Carvalho Chehab------------------------------
9*cf065a7dSRandy DunlapThere is now a new module endpoint attribute called jam_host
10e92c45d2SMauro Carvalho Chehabattribute::
11e92c45d2SMauro Carvalho Chehab
12e92c45d2SMauro Carvalho Chehab	jam_host: boolean=0/1
13e92c45d2SMauro Carvalho Chehab
14e92c45d2SMauro Carvalho ChehabThis attribute and accompanying code is only included if the
15e92c45d2SMauro Carvalho ChehabKconfig parameter TCM_QLA2XXX_DEBUG is set to Y
16e92c45d2SMauro Carvalho Chehab
17e92c45d2SMauro Carvalho ChehabBy default this jammer code and functionality is disabled
18e92c45d2SMauro Carvalho Chehab
19e92c45d2SMauro Carvalho ChehabUse this attribute to control the discarding of SCSI commands to a
20e92c45d2SMauro Carvalho Chehabselected host.
21e92c45d2SMauro Carvalho Chehab
22e92c45d2SMauro Carvalho ChehabThis may be useful for testing error handling and simulating slow drain
23e92c45d2SMauro Carvalho Chehaband other fabric issues.
24e92c45d2SMauro Carvalho Chehab
25e92c45d2SMauro Carvalho ChehabSetting a boolean of 1 for the jam_host attribute for a particular host
26e92c45d2SMauro Carvalho Chehabwill discard the commands for that host.
27e92c45d2SMauro Carvalho Chehab
28e92c45d2SMauro Carvalho ChehabReset back to 0 to stop the jamming.
29e92c45d2SMauro Carvalho Chehab
30e92c45d2SMauro Carvalho ChehabEnable host 4 to be jammed::
31e92c45d2SMauro Carvalho Chehab
32e92c45d2SMauro Carvalho Chehab  echo 1 > /sys/kernel/config/target/qla2xxx/21:00:00:24:ff:27:8f:ae/tpgt_1/attrib/jam_host
33e92c45d2SMauro Carvalho Chehab
34e92c45d2SMauro Carvalho ChehabDisable jamming on host 4::
35e92c45d2SMauro Carvalho Chehab
36e92c45d2SMauro Carvalho Chehab  echo 0 > /sys/kernel/config/target/qla2xxx/21:00:00:24:ff:27:8f:ae/tpgt_1/attrib/jam_host
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