sg_inq+sg_vpd: add --force option to bypass checking supported vpd pages page and fetch requested page directly; H. Reinecke

git-svn-id: https://svn.bingwo.ca/repos/sg3_utils/trunk@696 6180dd3e-e324-4e3e-922d-17de1ae2f315

1 files changed, 12 insertions, 2 deletions

diff --git a/doc/sg_vpd.8 b/doc/sg_vpd.8
index 4e3e15d3..25c6a0e6 100644
--- a/doc/sg_vpd.8
+++ b/doc/sg_vpd.8
@@ -1,4 +1,4 @@
-.TH SG_VPD "8" "February 2016" "sg3_utils\-1.42" SG3_UTILS
+.TH SG_VPD "8" "April 2016" "sg3_utils\-1.43" SG3_UTILS
 .SH NAME
 sg_vpd \- fetch SCSI VPD page and/or decode its response
 .SH SYNOPSIS
@@ -6,7 +6,7 @@ sg_vpd \- fetch SCSI VPD page and/or decode its response
 [\fI\-\-all\fR] [\fI\-\-enumerate\fR] [\fI\-\-help\fR] [\fI\-\-hex\fR]
 [\fI\-\-ident\fR] [\fI\-\-inhex=FN\fR] [\fI\-\-long\fR] [\fI\-\-maxlen=LEN\fR]
 [\fI\-\-page=PG\fR] [\fI\-\-quiet\fR] [\fI\-\-raw\fR] [\fI\-\-vendor=VP\fR]
-[\fI\-\-verbose\fR] [\fI\-\-version\fR] [\fIDEVICE\fR]
+[\fI\-\-force\fR] [\fI\-\-verbose\fR] [\fI\-\-version\fR] [\fIDEVICE\fR]
 .SH DESCRIPTION
 .\" Add any additional description here
 .PP
@@ -60,6 +60,16 @@ summary lines of all VPD pages whose number matches \fIPG\fR. May be used
 with \fI\-\-vendor=VP\fR to restrict output to known vendor specific pages
 for vendor/product \fIVP\fR.
 .TP
+\fB\-f\fR, \fB\-\-force\fR
+As a sanity check, the normal action when fetching VPD pages other than
+page 0x0 (the "Supported VPD pages" VPD page), is to first fetch page 0x0
+and only if the requested page is one of the supported pages, to go ahead
+and fetch the requested page.
+.br
+When this option is given, skip checking of VPD page 0x0 before accessing
+the requested VPD page. The prior check of VPD page 0x0 is known to
+crash certain USB devices, so use with care.
+.TP
 \fB\-h\fR, \fB\-\-help\fR
 outputs the usage message summarizing command line options then exits.
 Ignores \fIDEVICE\fR if given.