diff options
author | Sivaram Nair <sivaramn@nvidia.com> | 2013-02-26 14:12:05 +0200 |
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committer | Riham Haidar <rhaidar@nvidia.com> | 2013-03-01 12:48:27 -0800 |
commit | a27402e47e1a8e72af26bf783f293c3b82cb5164 (patch) | |
tree | 22114a71552f48fd5bb3a0e13587c7c60a20ea0e /Documentation | |
parent | 32fe3a1a3bfaf74c794cf5a61aeedf9f268c7aad (diff) |
EDP: update documentation
Adding documentation about debugfs features and tegra specific
implementation.
Change-Id: I087391b522ee89cfe7a75ad44c4ea005c139c1b2
Signed-off-by: Sivaram Nair <sivaramn@nvidia.com>
Reviewed-on: http://git-master/r/204195
Reviewed-by: Juha Tukkinen <jtukkinen@nvidia.com>
Diffstat (limited to 'Documentation')
-rw-r--r-- | Documentation/edp/debugfs | 36 | ||||
-rw-r--r-- | Documentation/edp/governors | 8 |
2 files changed, 44 insertions, 0 deletions
diff --git a/Documentation/edp/debugfs b/Documentation/edp/debugfs new file mode 100644 index 000000000000..654eb259c512 --- /dev/null +++ b/Documentation/edp/debugfs @@ -0,0 +1,36 @@ + +EDP DEBUGFS + +1. Introduction + +EDP debugfs root is at /sys/kernel/debug/edp. Manager and client objects +appear as subfolders under the root, forming a tree structure similar to +the EDP sysfs entries. + +Following sections describe the debufs attributes. Unless stated +otherwise, all attributes have RW permissions. + +2. EDP manager + + [1] cap: Peak current capacity - reading will return the present + value and writting will set a new cap. Note that the cap can + not be set lower than the sum of E0 currents of all clients. + Lowering the cap might result in throttling of clients. + + [2] status (read-only): Gives a snap shot of the manager and its + budget distribution. + +3. EDP clients + +Following is the list of common client attributes. The client driver may +add additional device specfic attributes under the same folder. + + [1] current: Force a certain client's E-state. Write the state + index to force the state. Read will return the state value. + The request is processed only if it can be handled fully + (that is, the client will not be assigned a lesser E-state). + If the state can not be changed due to insufficient budget, + the operation fails. Note that this request may be + overriden by other requests. To prevent this from happening, + choose the debug policy governor (see the EDP governor + documentation). diff --git a/Documentation/edp/governors b/Documentation/edp/governors index 5dc7b7107d35..30e12b200a00 100644 --- a/Documentation/edp/governors +++ b/Documentation/edp/governors @@ -74,3 +74,11 @@ client is throttled first. 8. Round Robin (RR) In this policy, clients are throttled in a round-robin fashion. + +9. Debug + +When the debug policy governor is selected, the framework stops +processing requests from clients. Further changes to the client E-states +can only be made manually via debugfs (see the EDP debugfs +documentation). This allows one to do manual budget allocations and +prevent clients from overriding them. |