Am Dienstag, den 23.10.2018, 18:28 +0100 schrieb Emil Velikov: > On Thu, 18 Oct 2018 at 21:07, Christian Gmeiner > > <christian.gmeiner@xxxxxxxxx> wrote: > > > > Since kernel 4.17 (drm/etnaviv: remove the need for a gpu-subsystem DT > > node) the etnaviv DRM driver doesn't have an associated DT node > > anymore. This is technically correct, as the etnaviv device is a > > virtual device driving multiple hardware devices. > > > > Before 4.17 the userspace had access to the following information: > > # cat /sys/dev/char/226:128/device/uevent > > DRIVER=etnaviv > > OF_NAME=gpu-subsystem > > OF_FULLNAME=/gpu-subsystem > > OF_COMPATIBLE_0=fsl,imx-gpu-subsystem > > OF_COMPATIBLE_N=1 > > MODALIAS=of:Ngpu-subsystemT<NULL>Cfsl,imx-gpu-subsystem > > DRIVER=imx-drm > > OF_NAME=display-subsystem > > OF_FULLNAME=/display-subsystem > > OF_COMPATIBLE_0=fsl,imx-display-subsystem > > OF_COMPATIBLE_N=1 > > > > Afer 4.17: > > # cat /sys/dev/char/226:128/device/uevent > > DRIVER=etnaviv > > MODALIAS=platform:etnaviv > > > > Mostly relaying what I mentioned previously [1], yet forgot to CC RobH. > > - Are the OF entries in uevent part of the ABI or not? Can we have that > documented anywhere? > > There are very few mentions in the official kernel doc - Documentation/ABI/ > Obviously it doesn't mention anything OF_* but it neither does DRIVER > or MODALIAS. Yet if we change those $world will break ;-) The OF node has never been part of the etnaviv UABI, simply due to the fact that it's still possible to instantiate the etnaviv driver from a platform file, instead of a devicetree node. > > - How can we distinguish in the (perhaps hypothetical) case when > there's two or more etnaviv devices? Why not simply use the DRM minor? All you need is an arbitrary handle to grab the right instance. Regards, Lucas _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel
