From: Mauro Carvalho Chehab Date: Wed, 15 Apr 2020 14:45:19 +0000 (+0200) Subject: docs: dt: convert changesets to ReST X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=afb6120519ae26272946cb4566de5b25fc4f74e0;p=linux.git docs: dt: convert changesets to ReST - Add a SPDX header; - Add a document title; - Some whitespace fixes and new line breaks; - Add it to devicetree/index.rst. Signed-off-by: Mauro Carvalho Chehab Signed-off-by: Rob Herring --- diff --git a/Documentation/devicetree/changesets.rst b/Documentation/devicetree/changesets.rst new file mode 100644 index 0000000000000..c7fd8cd6a270d --- /dev/null +++ b/Documentation/devicetree/changesets.rst @@ -0,0 +1,37 @@ +.. SPDX-License-Identifier: GPL-2.0 + +============= +DT Changesets +============= + +A DT changeset is a method which allows one to apply changes +in the live tree in such a way that either the full set of changes +will be applied, or none of them will be. If an error occurs partway +through applying the changeset, then the tree will be rolled back to the +previous state. A changeset can also be removed after it has been +applied. + +When a changeset is applied, all of the changes get applied to the tree +at once before emitting OF_RECONFIG notifiers. This is so that the +receiver sees a complete and consistent state of the tree when it +receives the notifier. + +The sequence of a changeset is as follows. + +1. of_changeset_init() - initializes a changeset + +2. A number of DT tree change calls, of_changeset_attach_node(), + of_changeset_detach_node(), of_changeset_add_property(), + of_changeset_remove_property, of_changeset_update_property() to prepare + a set of changes. No changes to the active tree are made at this point. + All the change operations are recorded in the of_changeset 'entries' + list. + +3. of_changeset_apply() - Apply the changes to the tree. Either the + entire changeset will get applied, or if there is an error the tree will + be restored to the previous state. The core ensures proper serialization + through locking. An unlocked version __of_changeset_apply is available, + if needed. + +If a successfully applied changeset needs to be removed, it can be done +with of_changeset_revert(). diff --git a/Documentation/devicetree/changesets.txt b/Documentation/devicetree/changesets.txt deleted file mode 100644 index cb488eeb63537..0000000000000 --- a/Documentation/devicetree/changesets.txt +++ /dev/null @@ -1,31 +0,0 @@ -A DT changeset is a method which allows one to apply changes -in the live tree in such a way that either the full set of changes -will be applied, or none of them will be. If an error occurs partway -through applying the changeset, then the tree will be rolled back to the -previous state. A changeset can also be removed after it has been -applied. - -When a changeset is applied, all of the changes get applied to the tree -at once before emitting OF_RECONFIG notifiers. This is so that the -receiver sees a complete and consistent state of the tree when it -receives the notifier. - -The sequence of a changeset is as follows. - -1. of_changeset_init() - initializes a changeset - -2. A number of DT tree change calls, of_changeset_attach_node(), -of_changeset_detach_node(), of_changeset_add_property(), -of_changeset_remove_property, of_changeset_update_property() to prepare -a set of changes. No changes to the active tree are made at this point. -All the change operations are recorded in the of_changeset 'entries' -list. - -3. of_changeset_apply() - Apply the changes to the tree. Either the -entire changeset will get applied, or if there is an error the tree will -be restored to the previous state. The core ensures proper serialization -through locking. An unlocked version __of_changeset_apply is available, -if needed. - -If a successfully applied changeset needs to be removed, it can be done -with of_changeset_revert(). diff --git a/Documentation/devicetree/index.rst b/Documentation/devicetree/index.rst index 7a6aad7d384a5..a9757ec5070ea 100644 --- a/Documentation/devicetree/index.rst +++ b/Documentation/devicetree/index.rst @@ -9,3 +9,4 @@ Open Firmware and Device Tree usage-model writing-schema + changesets