On 27 April 2018 at 12:31, Robert Foss <robert.foss@xxxxxxxxxxxxx> wrote: > drmHandleMatch is intended to allow for userspace to filter out > devices that it does not want to open. > > Opening specific devices using paths alone is not a reliable due to > probing order. This function intends to provide a mechanism > for filtering out devices that don't fit what you need using an > extensible set of filters. > > drm_match_key_t is intended to be extended with whatever > filter that would come in handy down the line. > > As a catch-all filter, the DRM_MATCH_FUNCTION was included > which allows the caller to filter based on an arbitrary function. > > An function pointer filter could of course filter based on > anything. But for the sake of convenience a few other simple > filters have been included. > > If the function pointer filter ends up being called with a > boilerplate fp by mutliple libdrm users, perhaps that funtion > could be moved into libdrm at a future date. > > Signed-off-by: Robert Foss <robert.foss@xxxxxxxxxxxxx> > --- > > This patch implements a simple function for matching DRM device FDs > against the desired properties of a device that you are looking for. > > The discussion that led to this series can be found here: > https://lists.freedesktop.org/archives/mesa-dev/2018-January/183878.html > > The RFC can be found here: > https://www.spinics.net/lists/dri-devel/msg172398.html > > Since the RFC I opted to rework the patch to be more extensible. > The previous implementation would have been problematic if the > drmVersion or drmDevice structs ever needed to be changed or > removed. Or indeed if more properties were to become interesting. > > As it is now, it is basially implemented as per Daniel Stones suggestion in > the RFC discussion. > > Changes since RFC: > - Reworked proposal to be not be based on structs in order to be more > flexible. > - Now uses filters of different types. > - Caller can supply any number of predefined and function pointer > filter. > > xf86drm.h | 24 ++++++++++++++++++++ > xf86drmMode.c | 70 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ > 2 files changed, 94 insertions(+) > Instead of spending too much time thinking of a future-proof API, can I suggest getting a handful of users first. And only after that lifting it to a helper - If needed. Here are some examples - anv [1] and xf86-video-amdgpu [2]. Note latter is not merged yet. Practically any implementation is as trivial as: ret = drmGetDevices2(...) for (i = 0; i < ret; i++) { compare_device_specifics(...) } drmFreeDevices(...) What do you guys think? Emil [1] https://cgit.freedesktop.org/mesa/mesa/tree/src/intel/vulkan/anv_device.c#n615 [2] https://lists.freedesktop.org/archives/amd-gfx/2018-April/020936.html _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel
