On 2 March 2018 at 11:29, Thierry Reding <thierry.red...@gmail.com> wrote:
> From: Thierry Reding <tred...@nvidia.com>
> ARM SoCs usually have their DRM/KMS devices on the platform bus, so add
> support for this bus in order to allow use of the DRI_PRIME environment
> variable with those devices.
> While at it, also support the host1x bus, which is effectively the same
> but uses an additional layer in the bus hierarchy.
> Note that it isn't enough to support the bus that has the rendering GPU
> because the loader code will also try to construct an ID path tag for a
> scanout-only device if it is the default that is being opened.
> The ID path tag for a device can be obtained by running udevadm info on
> the device node, as shown in this example on NVIDIA Tegra:
> $ udevadm info /dev/dri/card0 | grep ID_PATH_TAG
> E: ID_PATH_TAG=platform-50000000_host1x
> The corresponding OF_FULLNAME property, from which the ID_PATH_TAG is
> constructed, can be found in the sysfs "uevent" attribute for the card0
> device's parent:
> $ grep OF_FULLNAME /sys/devices/platform/50000000.host1x/drm/uevent
> Similarily, /dev/dri/card1 corresponds to the GPU:
> $ udevadm info /dev/dri/card1 | grep ID_PATH_TAG
> E: ID_PATH_TAG=platform-57000000_gpu
> $ grep OF_FULLNAME /sys/devices/platform/57000000.gpu/uevent
> Changes in v2:
> - avoid confusing pre-increment in strdup()
> - add examples of tags to commit log
> Reviewed-by: Eric Engestrom <e...@engestrom.ch>
> Signed-off-by: Thierry Reding <tred...@nvidia.com>
Smashing, thanks for the examples Thierry.
Reviewed-by: Emil Velikov <emil.veli...@collabora.com>
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