Implement a generic drmGetDeviceNameFromFd2() to use on non-linux systems without sysfs.
v2: remove min < base test as requested by Emil
Signed-off-by: Jonathan Gray jsg@jsg.id.au --- xf86drm.c | 44 ++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 42 insertions(+), 2 deletions(-)
diff --git a/xf86drm.c b/xf86drm.c index f6850aa2..f684c017 100644 --- a/xf86drm.c +++ b/xf86drm.c @@ -3627,7 +3627,47 @@ char *drmGetDeviceNameFromFd2(int fd) fclose(f); return device_name; #else -#warning "Missing implementation of drmGetDeviceNameFromFd2" - return NULL; + struct stat sbuf; + char node[PATH_MAX + 1]; + const char *dev_name; + int node_type; + int maj, min, n, base; + + if (fstat(fd, &sbuf)) + return NULL; + + maj = major(sbuf.st_rdev); + min = minor(sbuf.st_rdev); + + if (maj != DRM_MAJOR || !S_ISCHR(sbuf.st_mode)) + return NULL; + + node_type = drmGetMinorType(min); + if (node_type == -1) + return NULL; + + switch (node_type) { + case DRM_NODE_PRIMARY: + dev_name = DRM_DEV_NAME; + break; + case DRM_NODE_CONTROL: + dev_name = DRM_CONTROL_DEV_NAME; + break; + case DRM_NODE_RENDER: + dev_name = DRM_RENDER_DEV_NAME; + break; + default: + return NULL; + }; + + base = drmGetMinorBase(node_type); + if (base < 0) + return NULL; + + n = snprintf(node, PATH_MAX, dev_name, DRM_DIR_NAME, min - base); + if (n == -1 || n >= PATH_MAX) + return NULL; + + return strdup(node); #endif }