From 8a73372e62a73fe8d874aa39458c508cdb5bb6f4 Mon Sep 17 00:00:00 2001 From: Vasyl Vavrychuk Date: Wed, 29 Jan 2020 16:08:41 +0100 Subject: [PATCH] xf86drm: fix subsystem type lookup for virtio mmio-based devices Currently the code assumes that a virtio based device is always located on the PCI bus. Modify the parser to make it check the device's parent directory to determine on which bus it is located. Output for virtio-pci is the PCI bus. Output for virtio-mmio is the Platform bus. Signed-off-by: Vasyl Vavrychuk Signed-off-by: Mikhail Golubev Reviewed-by: Gurchetan Singh Tested-by: Gurchetan Singh --- xf86drm.c | 15 ++++++++++++--- 1 file changed, 12 insertions(+), 3 deletions(-) diff --git a/xf86drm.c b/xf86drm.c index b147912..d240f95 100644 --- a/xf86drm.c +++ b/xf86drm.c @@ -3005,10 +3005,20 @@ static int drmParseSubsystemType(int maj, int min) { #ifdef __linux__ char path[PATH_MAX + 1] = ""; + char real_path[PATH_MAX + 1] = ""; + int subsystem_type; - snprintf(path, PATH_MAX, "/sys/dev/char/%d:%d/device", maj, min); + snprintf(path, sizeof(path), "/sys/dev/char/%d:%d/device", maj, min); + if (!realpath(path, real_path)) + return -errno; + snprintf(path, sizeof(path), "%s", real_path); - return get_subsystem_type(path); + subsystem_type = get_subsystem_type(path); + if (subsystem_type == DRM_BUS_VIRTIO) { + strncat(path, "/..", PATH_MAX); + subsystem_type = get_subsystem_type(path); + } + return subsystem_type; #elif defined(__OpenBSD__) || defined(__DragonFly__) return DRM_BUS_PCI; #else @@ -3710,7 +3720,6 @@ process_device(drmDevicePtr *device, const char *d_name, switch (subsystem_type) { case DRM_BUS_PCI: - case DRM_BUS_VIRTIO: return drmProcessPciDevice(device, node, node_type, maj, min, fetch_deviceinfo, flags); case DRM_BUS_USB: -- 2.7.4