Hi Marius, On Mon, 2018-08-20 at 23:00 +0300, Marius Vlad wrote: > Simple protocol extension to manage DRM lease. Based on the work by Keith > Packard in [1], respectively [2]. > > [1] > https://cgit.freedesktop.org/mesa/drm/commit/?id=c4171535389d72e9135c9615cecd07b346fd6d7e > [2] > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?h=v4.15-rc9&id=62884cd386b876638720ef88374b31a84ca7ee5f > > Signed-off-by: Marius Vlad <marius-cristian.v...@nxp.com> > > Changes since v2: > - advertise connector names when creating a lease request object (Pekka > Paalanen) > - when revoking the lease use the lease object instead of lessee id (Pekka > Paalanen) > - various grammar/spelling fixes (Pekka Paalanen) > > Changes since v1: > - added manager: advertise lease capability and manage the lease (Daniel > Stone) > - add request(s) for adding connector/crtc/plane to behave more like dmabuf > (Daniel Stone) > --- > Some caveats while at it. This is just in RFC form adapted from the comments > I've mostly got from Pekka Paalanen. It most certainly doesn't address all > the issues > brought up: like multi-node card environments/system, doing a TEST_ONLY > commit before giving out a lease, or takes hot-plugging into consideration. > As I was side-tracked to other things and > being on hiatus for a while, I wanted first to get some impressions first if > indeed this is the right approach and do some incremental updates afterwards. > > The are some issues which I'd like to point out from the beginning, which > require some further comments. In no particular order: > > I've found that I can't pass a wl_array as a way to advertise various > information to the client. (wl_array works fine with integers not with > allocated data). It would probably be better to advertise also > monitor name, other EDID info or available modes, but at the moment I only > join-split a delimiter between connector names and send it out as a string. > While it is ugly I'm not aware of a way to send this information back to the > client in the form of a list. > > The client is aware before hand of this delimiter and has the number of > entries: > can easily choose or pick one of the connectors. It could be that there are > some other ways this can be achieved, I welcome any kind of feedback here.
Why not just send the connectors one by one, a single event with all relevant information for each? Especially EDID info would be most useful for finding the right VR headset. > Secondly, when doing a modeset, the client requires a valid mode > (drmModeModeInfo). I'm currently unsure how to pass this back to the client. > The obvious type="object" interface="drmModeModeInfo" fails to link and > instead > I rely on the fact that a) the client can retrieve IDs from the lease using > lease API (drmModeGetLease()) which gives a connector id -- > or alternately can also use a wl_array to pass that, > and b) the client can use the leased fd to iterate over connectors. > Matching those two would allow to get a valid > drmModeModeInfo object to pass it when modesetting (for more info > see the client implementation provided at the end). > Question is, is this an acceptable way of doing it? Do note that this > can only be "used" after the lease has been created. Can't the client query available modes on the passed connector via the leased fd? > A server/client implementation to match this protocol > can be found at > https://gitlab.freedesktop.org/marius.vlad0/weston/commits/new-drm-lease This crashed for me in drm_lease_manager_create_lease_req with a NULL pointer dereference because head->output == NULL for an unconnected head. Also I noticed zwm_kms_lease_request_v1_implementation is missing the .destroy request callback. > Makefile.am | 1 + > unstable/drm-lease/README | 4 + > unstable/drm-lease/drm-lease-unstable-v1.xml | 173 > +++++++++++++++++++++++++++ > 3 files changed, 178 insertions(+) > create mode 100644 unstable/drm-lease/README > create mode 100644 unstable/drm-lease/drm-lease-unstable-v1.xml > > diff --git a/Makefile.am b/Makefile.am > index 6394e26..5d13dca 100644 > --- a/Makefile.am > +++ b/Makefile.am > @@ -4,6 +4,7 @@ unstable_protocols = > \ > unstable/pointer-gestures/pointer-gestures-unstable-v1.xml > \ > unstable/fullscreen-shell/fullscreen-shell-unstable-v1.xml > \ > unstable/linux-dmabuf/linux-dmabuf-unstable-v1.xml > \ > + unstable/drm-lease/drm-lease-unstable-v1.xml > \ > unstable/text-input/text-input-unstable-v1.xml > \ > unstable/text-input/text-input-unstable-v3.xml > \ > unstable/input-method/input-method-unstable-v1.xml > \ > diff --git a/unstable/drm-lease/README b/unstable/drm-lease/README > new file mode 100644 > index 0000000..a25600c > --- /dev/null > +++ b/unstable/drm-lease/README > @@ -0,0 +1,4 @@ > +Linux DRM lease > + > +Maintainers: > +Marius Vlad <marius-cristian.v...@nxp.com> > diff --git a/unstable/drm-lease/drm-lease-unstable-v1.xml > b/unstable/drm-lease/drm-lease-unstable-v1.xml > new file mode 100644 > index 0000000..6cb3c0a > --- /dev/null > +++ b/unstable/drm-lease/drm-lease-unstable-v1.xml > @@ -0,0 +1,173 @@ > +<?xml version="1.0" encoding="UTF-8"?> > +<protocol name="drm_lease_unstable_v1"> > + > +<copyright> > + Copyright 2018 NXP > + > + Permission is hereby granted, free of charge, to any person obtaining a > + copy of this software and associated documentation files (the > "Software"), > + to deal in the Software without restriction, including without limitation > + the rights to use, copy, modify, merge, publish, distribute, sublicense, > + and/or sell copies of the Software, and to permit persons to whom the > + Software is furnished to do so, subject to the following conditions: > + > + The above copyright notice and this permission notice (including the next > + paragraph) shall be included in all copies or substantial portions of the > + Software. > + > + THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS > OR > + IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, > + FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL > + THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR > OTHER > + LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING > + FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER > + DEALINGS IN THE SOFTWARE. > +</copyright> > + > + <interface name="zwp_kms_lease_manager_v1" version="1"> > + <description summary="lease manager"> > + This interface makes use of DRM lease written by Keith Packard. > + > + A DRM master can create another DRM master and ``lease'' resources it > has > + control over to the new DRM master. Once leased, resources can not be > + controlled by the owner unless the owner cancels the lease, or the new > + DRM master is closed. > + > + A lease is a contract between the Lessor (DRM master which has leased > out > + resources to one or more other DRM masters) and a Lessee > + (DRM master which controls resources leased from another DRM master). > This > + contract specifies which resources may be controlled by the Lessee. > + > + The Lessee can issue modesetting/page-flipping atomic operations etc., > + just like a Lessor using the leased file-descriptor passed by the > Lessor. > + > + Besides the leased file-descriptor, an integer is used to uniquely > + identify a Lessee within the tree of DRM masters descending from a > single > + Owner. Once the Lessee has finished with the resources it had used, the > + Lessee ID can be used to revoke that lease. > + > + Warning! The protocol described in this file is experimental and > + backward incompatible changes may be made. Backward compatible changes > + may be added together with the corresponding interface version bump. > + Backward incompatible changes are done by bumping the version number in > + the protocol and interface names and resetting the interface version. > + Once the protocol is to be declared stable, the 'z' prefix and the > + version number in the protocol and interface names are removed and the > + interface version number is reset. > + </description> > + > + <request name="destroy" type="destructor"> > + <description summary="destroys the manager"> > + This has no effect on any remaining objects created through this > + interface. > + </description> > + </request> > + > + <request name="create_lease_req"> > + <description summary="create a temporary object for managing the > lease"> > + Create an object for temporarily storing all the KMS resources to be > leased. > + </description> > + <arg name="params_id" type="new_id" > interface="zwp_kms_lease_request_v1" > + summary="the new temporary"/> > + </request> > + > + <event name="connectors"> > + <description summary="advertise which connectors can be used to > request creation for a lease"> > + This event advertises leasable connectors. When multiple connectors > are > + advertised, the client should properly parse and choose one of > connectors > + A client trying to create a lease using > zwp_kms_lease_request_v1::create > + request would use this connector name. > + </description> > + <arg name="connectors" type="string" summary="list of connector > entries, split by '|' char"/> > + <arg name="connectors_entries" type="uint" summary="number of > connectors found in connectors string"/> > + </event> > + > + </interface> > + > + <interface name="zwp_kms_lease_v1" version="1"> > + <description summary="the lease object itself"> > + This interface represents the lease object and encapsulates the lease > + properties. This objected is sent by zwp_kms_lease_request_v1::created > + event. Use this object to retrieve lease properties. > + </description> > + > + <request name="destroy" type="destructor"> > + <description summary="destroys the temporary lease request object"> > + This has no effect on any remaining objects created through this > + interface. > + </description> > + </request> > + > + <request name="get_lease_info"> > + <description summary="request to retrieve info about the lease"> > + Request to retrieve lease information, like leased fd, monitor > + and connector name. > + </description> > + </request> > + > + <event name="lease_info"> > + <description summary="returns information about the lease"> > + This event returns (among other information about the connector > leased) > + the leased fd which is required for modesetting or queying page > flips. > + The client can use the leased fd to find out DRM-related information > + like connector, CRTC, and plane ID using drmModeGetLease(). Using > that > + information it can derive a suitable mode useful when performing > modeset. > + </description> > + <arg name="leased_fd" type="fd" summary="leased fd" /> > + <arg name="conn_name" type="string" summary="connector name of the > lease" /> > + <arg name="monitor_name" type="string" summary="monitor name" /> > + </event> > + </interface> > + > + <interface name="zwp_kms_lease_request_v1" version="1"> > + <description summary="lease request object"> > + This interface is used for managing zwp_kms_lease_v1 object. It is used > + to create a zwp_kms_lease_v1 object (the actual lease object) and also > to > + revoke the lease. > + </description> > + > + <request name="destroy" type="destructor"> > + <description summary="destroys the lease request object"> > + This has no effect on any remaining objects created through this > + interface. > + </description> > + </request> > + > + <request name="create"> There's a level of indentation is missing from here. > + <description summary="create"> > + Create a lease using the connector output name received in > zwp_kms_lease_manager_v1::connectors. > + Any attempt to use an incorrect connector name will reswult in > zwp_kms_lease_request_v1::failed. > + </description> > + <arg name="connector" type="string" summary="connector output name"/> > + </request> > + > + <request name="revoke"> > + <description summary="revoke"> > + Revoke the lease, using the zwp_kms_lease_v1 objected received in > + zwp_kms_lease_request_v1::created event. > + </description> > + <arg name="lease_obj" type="object" interface="zwp_kms_lease_v1" > summary="lease object to remove" /> > + </request> > + > + <event name="created"> > + <description summary="lease created successfully"> > + This event indicates that the lease has been created. It provides a > zwp_kms_lease_v1 object > + used for retrieving the fd representing the lease. > + </description> > + <arg name="lease_obj" type="new_id" interface="zwp_kms_lease_v1" > summary="the lease obj"/> > + </event> > + > + <event name="failed"> > + <description summary="lease could not be created"> > + This event indicates that the lease could not be created/revoked. > + </description> > + </event> > + > + <event name="revoked"> > + <description summary="lease revoked successfully"> > + This event indicates that the lease has been revoked. > + </description> > + </event> > + > + </interface> > +</protocol> regards Philipp _______________________________________________ wayland-devel mailing list wayland-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/wayland-devel