From f9bc48d41d99f2cd4d603561b35fa5c6aedaf169 Mon Sep 17 00:00:00 2001 From: Thierry Reding Date: Wed, 21 Dec 2016 14:15:06 +0100 Subject: [PATCH] loader: Add support for platform and host1x busses 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 OF_FULLNAME=/host1x@50000000 Similarily, /dev/dri/card1 corresponds to the GPU: $ udevadm info /dev/dri/card1 | grep ID_PATH_TAG E: ID_PATH_TAG=platform-57000000_gpu and: $ grep OF_FULLNAME /sys/devices/platform/57000000.gpu/uevent OF_FULLNAME=/gpu@57000000 Changes in v2: - avoid confusing pre-increment in strdup() - add examples of tags to commit message Reviewed-by: Eric Engestrom Reviewed-by: Emil Velikov Signed-off-by: Thierry Reding --- src/loader/loader.c | 27 +++++++++++++++++++++++++++ 1 file changed, 27 insertions(+) diff --git a/src/loader/loader.c b/src/loader/loader.c index 92b4c5204b1..43275484cc2 100644 --- a/src/loader/loader.c +++ b/src/loader/loader.c @@ -120,6 +120,33 @@ static char *drm_construct_id_path_tag(drmDevicePtr device) device->businfo.pci->func) < 0) { return NULL; } + } else if (device->bustype == DRM_BUS_PLATFORM || + device->bustype == DRM_BUS_HOST1X) { + char *fullname, *name, *address; + + if (device->bustype == DRM_BUS_PLATFORM) + fullname = device->businfo.platform->fullname; + else + fullname = device->businfo.host1x->fullname; + + name = strrchr(fullname, '/'); + if (!name) + name = strdup(fullname); + else + name = strdup(name + 1); + + address = strchr(name, '@'); + if (address) { + *address++ = '\0'; + + if (asprintf(&tag, "platform-%s_%s", address, name) < 0) + tag = NULL; + } else { + if (asprintf(&tag, "platform-%s", name) < 0) + tag = NULL; + } + + free(name); } return tag; } -- 2.30.2