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| author | Alexander Shishkin <alexander.shishkin@linux.intel.com> | 2016-09-26 15:27:05 +0300 |
|---|---|---|
| committer | Alexander Shishkin <alexander.shishkin@linux.intel.com> | 2016-11-18 17:06:34 +0200 |
| commit | b29f6d3e59a1ff8dd5c0aeae8594801a15efcc2c (patch) | |
| tree | 574216bbb03ac15f6eeea57d7b79959f419086a1 | |
| parent | bd566189723d919e6081b494856337ef61a23f9f (diff) | |
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: Alexander Shishkin <alexander.shishkin@linux.intel.com>
| -rw-r--r-- | Documentation/trace/stm.txt | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/Documentation/trace/stm.txt b/Documentation/trace/stm.txt index 349869851463..11cff47eecce 100644 --- a/Documentation/trace/stm.txt +++ b/Documentation/trace/stm.txt @@ -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 =========== |