From: Tvrtko Ursulin <[email protected]> There is no need to iterate over /sys/class/drm/card* directories looking for the one which matches our major and minor, when we can directly find the right one via the /sys/dev/char/<major>:<minor> symlink.
Signed-off-by: Tvrtko Ursulin <[email protected]> Suggested-by: Lionel Landwerlin <[email protected]> --- lib/igt_sysfs.c | 36 ++++++++++++------------------------ 1 file changed, 12 insertions(+), 24 deletions(-) diff --git a/lib/igt_sysfs.c b/lib/igt_sysfs.c index f0fef8d434ef..a4a87711ed0c 100644 --- a/lib/igt_sysfs.c +++ b/lib/igt_sysfs.c @@ -100,40 +100,28 @@ static int writeN(int fd, const char *buf, int len) */ char *igt_sysfs_path(int device, char *path, int pathlen, int *idx) { + unsigned int maj, min; struct stat st; + int len; if (device < 0 || fstat(device, &st) || !S_ISCHR(st.st_mode)) return NULL; + maj = major(st.st_rdev); + min = minor(st.st_rdev); + /* Only support master nodes. */ - if (minor(st.st_rdev) >= 64) + if (min >= 64) return NULL; - for (int n = 0; n < 16; n++) { - int len = snprintf(path, pathlen, "/sys/class/drm/card%d", n); - int ret, maj, min; - FILE *file; - - sprintf(path + len, "/dev"); - file = fopen(path, "r"); - if (!file) - continue; - - ret = fscanf(file, "%d:%d", &maj, &min); - fclose(file); - - if (ret != 2 || - major(st.st_rdev) != maj || - minor(st.st_rdev) != min) - continue; + len = snprintf(path, pathlen, "/sys/dev/char/%u:%u", maj, min); + if (len == pathlen) + return NULL; - path[len] = '\0'; - if (idx) - *idx = n; - return path; - } + if (idx) + *idx = min; - return NULL; + return path; } /** -- 2.14.1 _______________________________________________ Intel-gfx mailing list [email protected] https://lists.freedesktop.org/mailman/listinfo/intel-gfx
