My system (Dell XPS 15 9530 notebook) has two graphic cards. intel and nvidia.

$ dmesg|grep drm
[    0.776604] [drm] Initialized drm 1.1.0 20060810
[    0.777058] [drm] Memory usable by graphics device = 2048M
[    0.777085] [drm] VT-d active for gfx access
[    0.777106] fb: switching to inteldrmfb from simple
[    0.777248] [drm] Replacing VGA console driver
[    0.783559] [drm] Supports vblank timestamp caching Rev 2 (21.10.2013).
[    0.783565] [drm] Driver supports precise vblank timestamp query.
[    0.783582] [drm] DMAR active, disabling use of stolen memory
[    0.819251] [drm] Initialized i915 1.6.0 20150731 for 0000:00:02.0 on minor 0
[    0.891401] [drm] GMBUS [i915 gmbus vga] timed out, falling back to bit banging on pin 2
[    0.922294] fbcon: inteldrmfb (fb0) is primary device
[    2.057677] i915 0000:00:02.0: fb0: inteldrmfb frame buffer device
[    9.337216] [drm] Initialized nouveau 1.3.0 20120801 for 0000:02:00.0 on minor 1

both have KMS drivers. But there is only one display and optimus method:

$ dmesg|grep -i optimus
[    8.564103] pci 0000:02:00.0: optimus capabilities: enabled, status dynamic power, hda bios codec supported
[    8.564105] VGA switcheroo: detected Optimus DSM method \_SB_.PCI0.PEG0.PEGP handle


Code in xorg-wrapper.c:

    /* Detect if we need root rights, except when overriden by the config */
    if (needs_root_rights == -1) {
        for (i = 0; i < 16; i++) {
            snprintf(buf, sizeof(buf), DRM_DEV_NAME, DRM_DIR_NAME, i);
            fd = open(buf, O_RDWR);
            if (fd == -1)
                continue;

            total_cards++;

            memset(&res, 0, sizeof(struct drm_mode_card_res));
            r = ioctl(fd, DRM_IOCTL_MODE_GETRESOURCES, &res);
            if (r == 0 && res.count_connectors > 0)
                kms_cards++;

            close(fd);
        }
    }

    /* If we've found cards, and all cards support kms, drop root rights */
    if (needs_root_rights == 0 || (total_cards && kms_cards == total_cards)) {


detects such system as total_cards == 2 and kms_cards == 1 so it doesn't drop rights.

So I guess that this code above needs to be improved to properly detect such situation and allow dropping rights. Or was there a reason for requiring connectors > 0?