Commit b29f6d3e authored by Alexander Shishkin's avatar Alexander Shishkin
Browse files

stm class: Document stm_source channel assignment 



This patch adds an explanation of how and when stm_source devices are
assigned STP masters and channels.

Signed-off-by: default avatarAlexander Shishkin <alexander.shishkin@linux.intel.com>
parent bd566189

Documentation/trace/stm.txt

+10 −0
Original line number Diff line number Diff line
@@ -85,6 +85,16 @@ $ echo dummy_stm.0 > /sys/class/stm_source/console/stm_source_link 
For examples on how to use stm_source interface in the kernel, refer

to stm_console or stm_heartbeat drivers.



Each stm_source device will need to assume a master and a range of

channels, depending on how many channels it requires. These are

allocated for the device according to the policy configuration. If

there's a node in the root of the policy directory that matches the

stm_source device's name (for example, "console"), this node will be

used to allocate master and channel numbers. If there's no such policy

node, the stm core will pick the first contiguous chunk of channels

within the first available master. Note that the node must exist

before the stm_source device is connected to its stm device.



stm_console

===========