Getting mmap fail EINV with RPi4

[moroslantia]

I try to use RPi4 with DRM dispplay driver

  drm_init();

    /*A small buffer for LittlevGL to draw the screen's content*/
    static lv_color_t buf[DISP_BUF_SIZE],buf1[DISP_BUF_SIZE];

    /*Initialize a descriptor for the buffer*/
    static lv_disp_draw_buf_t disp_buf;
    lv_disp_draw_buf_init(&disp_buf, buf, buf1, DISP_BUF_SIZE);

    /*Initialize and register a display driver*/
    static lv_disp_drv_t disp_drv;
    lv_disp_drv_init(&disp_drv);

    disp_drv.draw_buf   = &disp_buf;
    disp_drv.flush_cb   = drm_flush;
    disp_drv.wait_cb    = drm_wait_vsync;
    disp_drv.hor_res    = 800;
    disp_drv.ver_res    = 480;
    lv_disp_drv_register(&disp_drv);

When starting my program it fails with

drm: Found plane_id: 86 connector_id: 32 crtc_id: 96
drm: 2560x1440 (550mm X 310mm) pixel format AR24
error: mmap fail (errno 22)
error: DRM buffer allocation failed

Any idea what's wrong?

[kisvegabor]

errno 22 means "invalid argument" in mmap. Can you print the arguments passed to mmap?

[moroslantia]

	// drm.c 644:649
	/* perform actual memory mapping */
	buf->map = mmap(0, creq.size, PROT_READ | PROT_WRITE, MAP_SHARED, drm_dev.fd, mreq.offset);
	if (buf->map == MAP_FAILED) {
		err("mmap fail (errno=%i), creq.size=%" PRIu64 ", drm_dev.fd=%i, mreq.offset=%" PRIx64, errno, creq.size, drm_dev.fd, mreq.offset);
		return -1;
	}

Running the demo gives:

drm: Found plane_id: 86 connector_id: 32 crtc_id: 96
drm: 2560x1440 (550mm X 310mm) pixel format AR24
error: mmap fail (errno=22), creq.size=14745600, drm_dev.fd=3, mreq.offset=118a7c000
error: DRM buffer allocation failed
Segmentation fault

[kisvegabor]

These values makes sense to me. I suspect that it's a Raspberry issue. 🙁

[stale]

This issue or pull request has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.