Added `bus mapping mode' (-M) which scans the whole configuration space

to find devices hiding behind misconfigured or misdesigned bus bridges.
This is intended only for debugging purposes and it's available only to root
as it can crash several well-known buggy chips.

1 files changed, 9 insertions, 0 deletions

diff --git a/lspci.man b/lspci.man
index 6021d92..dd91ce6 100644
--- a/lspci.man
+++ b/lspci.man
@@ -85,6 +85,15 @@ as directory containing PCI bus information instead of /proc/bus/pci.
 .B -m
 Dump PCI device data in machine readable form (both normal and verbose format supported)
 for easy parsing by scripts.
+.TP
+.B -M
+Invoke bus mapping mode which scans the bus extensively to find all devices including
+those behind misconfigured bridges etc. Please note that this is intended only for
+debugging and as it can crash the machine (only in case of buggy devices, but
+unfortunately these happen to exist), it's available only to root. Also using
+-M on PCI access methods which don't directly touch the hardware has no
+sense since the results are (modulo bugs in lspci) identical to normal listing
+modes.
 
 .SH PCILIB OPTIONS
 The PCI utilities use PCILIB (a portable library providing platform-independent