Thanks for the fix. It could be done in a simpler way that swap the va_start/va_end init/fini and empty_vm create/release. On Thu, Dec 14, 2023 at 5:04 PM Alban Browaeys <alban.browaeys@xxxxxxxxx> wrote: > > For the empty_vm initialization the range is empty which is not supported > by drm_mm_init. > > With CONFIG_DRM_DEBUG_MM set, I get: > ------------[ cut here ]------------ > kernel BUG at drivers/gpu/drm/drm_mm.c:965! > Internal error: Oops - BUG: 0 [#1] PREEMPT SMP ARM > Modules linked in: lima(+) drm_shmem_helper gpu_sched s5p_jpeg s5p_g2d > videobuf2_dma_contig videobuf2_memops v4l2_mem2mem videobuf2_v4l2 > videobuf2_common s5p_cec tun fuse configfs auth_rpcgss sunrpc ip_tables > x_tables autofs4 btrfs lzo_compress zlib_deflate raid10 raid456 > async_raid6_recov async_memcpy async_pq async_xor async_tx xor xor_neon > raid6_pq libcrc32c raid1 raid0 linear md_mod dm_mirror dm_region_hash > dm_log hid_logitech_hidpp hid_logitech_dj > CPU: 0 PID: 1033 Comm: systemd-udevd Not tainted 6.4.0-rc1-debug+ #230 > Hardware name: Samsung Exynos (Flattened Device Tree) > PC is at drm_mm_init+0x94/0x98 > LR is at 0x0 > Flags: nZCv IRQs on FIQs off Mode SVC_32 ISA ARM Segment none > drm_mm_init from lima_vm_create+0xcc/0x108 [lima] > lima_vm_create [lima] from lima_device_init+0xd8/0x4a0 [lima] > lima_device_init [lima] from lima_pdev_probe.part.0+0x6c/0x158 [lima] > lima_pdev_probe.part.0 [lima] from platform_probe+0x64/0xc0 > platform_probe from call_driver_probe+0x2c/0x110 > > The drm_mm.c line 965 is: > drivers/gpu/drm/drm_mm.c > void drm_mm_init(struct drm_mm *mm, u64 start, u64 size) > { > DRM_MM_BUG_ON(start + size <= start); > > lima_vm_create is called with va_start and va_end both unset > in lima_device_init line 371: > ldev->empty_vm = lima_vm_create(ldev); > > Signed-off-by: Alban Browaeys <alban.browaeys@xxxxxxxxx> > --- > drivers/gpu/drm/lima/lima_device.c | 2 +- > drivers/gpu/drm/lima/lima_drv.c | 2 +- > drivers/gpu/drm/lima/lima_vm.c | 10 +++++++--- > drivers/gpu/drm/lima/lima_vm.h | 3 ++- > 4 files changed, 11 insertions(+), 6 deletions(-) > > diff --git a/drivers/gpu/drm/lima/lima_device.c b/drivers/gpu/drm/lima/lima_device.c > index 02cef0cea657..bd3afff0f44a 100644 > --- a/drivers/gpu/drm/lima/lima_device.c > +++ b/drivers/gpu/drm/lima/lima_device.c > @@ -368,7 +368,7 @@ int lima_device_init(struct lima_device *ldev) > if (err) > goto err_out0; > > - ldev->empty_vm = lima_vm_create(ldev); > + ldev->empty_vm = lima_vm_create(ldev, false); > if (!ldev->empty_vm) { > err = -ENOMEM; > goto err_out1; > diff --git a/drivers/gpu/drm/lima/lima_drv.c b/drivers/gpu/drm/lima/lima_drv.c > index 10fd9154cc46..ca09142e0ac1 100644 > --- a/drivers/gpu/drm/lima/lima_drv.c > +++ b/drivers/gpu/drm/lima/lima_drv.c > @@ -219,7 +219,7 @@ static int lima_drm_driver_open(struct drm_device *dev, struct drm_file *file) > if (!priv) > return -ENOMEM; > > - priv->vm = lima_vm_create(ldev); > + priv->vm = lima_vm_create(ldev, true); > if (!priv->vm) { > err = -ENOMEM; > goto err_out0; > diff --git a/drivers/gpu/drm/lima/lima_vm.c b/drivers/gpu/drm/lima/lima_vm.c > index 2b2739adc7f5..7f9775eefd78 100644 > --- a/drivers/gpu/drm/lima/lima_vm.c > +++ b/drivers/gpu/drm/lima/lima_vm.c > @@ -197,7 +197,7 @@ u32 lima_vm_get_va(struct lima_vm *vm, struct lima_bo *bo) > return ret; > } > > -struct lima_vm *lima_vm_create(struct lima_device *dev) > +struct lima_vm *lima_vm_create(struct lima_device *dev, bool has_drm_mm) > { > struct lima_vm *vm; > > @@ -221,7 +221,10 @@ struct lima_vm *lima_vm_create(struct lima_device *dev) > goto err_out1; > } > > - drm_mm_init(&vm->mm, dev->va_start, dev->va_end - dev->va_start); > + if (has_drm_mm) { > + vm->has_drm_mm = true; > + drm_mm_init(&vm->mm, dev->va_start, dev->va_end - dev->va_start); > + } > > return vm; > > @@ -237,7 +240,8 @@ void lima_vm_release(struct kref *kref) > struct lima_vm *vm = container_of(kref, struct lima_vm, refcount); > int i; > > - drm_mm_takedown(&vm->mm); > + if (vm->has_drm_mm) > + drm_mm_takedown(&vm->mm); > > for (i = 0; i < LIMA_VM_NUM_BT; i++) { > if (vm->bts[i].cpu) > diff --git a/drivers/gpu/drm/lima/lima_vm.h b/drivers/gpu/drm/lima/lima_vm.h > index 3a7c74822d8b..e7443f410d6d 100644 > --- a/drivers/gpu/drm/lima/lima_vm.h > +++ b/drivers/gpu/drm/lima/lima_vm.h > @@ -30,6 +30,7 @@ struct lima_vm { > struct mutex lock; > struct kref refcount; > > + bool has_drm_mm; > struct drm_mm mm; > > struct lima_device *dev; > @@ -43,7 +44,7 @@ void lima_vm_bo_del(struct lima_vm *vm, struct lima_bo *bo); > > u32 lima_vm_get_va(struct lima_vm *vm, struct lima_bo *bo); > > -struct lima_vm *lima_vm_create(struct lima_device *dev); > +struct lima_vm *lima_vm_create(struct lima_device *dev, bool has_drm_mm); > void lima_vm_release(struct kref *kref); > > static inline struct lima_vm *lima_vm_get(struct lima_vm *vm) > -- > 2.39.2 >