Looks like in Linux next we can now get an oops when unloading omapdrm:
Unable to handle kernel NULL pointer dereference at virtual address 00000000 ... LR is at omap_drm_irq_uninstall+0xb0/0xe0 [omapdrm] ... [<bf6806a8>] (omap_drm_irq_uninstall [omapdrm]) from [<bf67f260>] (pdev_remove+0x50/0x88 [omapdrm]) [<bf67f260>] (pdev_remove [omapdrm]) from [<c058fa28>] (platform_drv_remove+0x24/0x3c) [<c058fa28>] (platform_drv_remove) from [<c058ddb8>] (device_release_driver_internal+0x160/0x1f4) [<c058ddb8>] (device_release_driver_internal) from [<c058de90>] (driver_detach+0x38/0x6c) [<c058de90>] (driver_detach) from [<c058d0b8>] (bus_remove_driver+0x4c/0xa0) [<c058d0b8>] (bus_remove_driver) from [<c058fb1c>] (platform_unregister_drivers+0x24/0x30) [<c058fb1c>] (platform_unregister_drivers) from [<c01e26e8>] (SyS_delete_module+0x150/0x218) [<c01e26e8>] (SyS_delete_module) from [<c01077a0>] (ret_fast_syscall+0x0/0x1c)
Fix the issue by checking get_vblank_counter() before trying to call it.
Signed-off-by: Tony Lindgren tony@atomide.com --- drivers/gpu/drm/omapdrm/omap_irq.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/omapdrm/omap_irq.c b/drivers/gpu/drm/omapdrm/omap_irq.c --- a/drivers/gpu/drm/omapdrm/omap_irq.c +++ b/drivers/gpu/drm/omapdrm/omap_irq.c @@ -303,8 +303,9 @@ void omap_drm_irq_uninstall(struct drm_device *dev) for (i = 0; i < dev->num_crtcs; i++) { wake_up(&dev->vblank[i].queue); dev->vblank[i].enabled = false; - dev->vblank[i].last = - dev->driver->get_vblank_counter(dev, i); + if (dev->driver->get_vblank_counter) + dev->vblank[i].last = + dev->driver->get_vblank_counter(dev, i); } spin_unlock_irqrestore(&dev->vbl_lock, irqflags); }