Merge branch 'linux-4.10' of git://github.com/skeggsb/linux into drm-next

- Regression fix from atomic conversion (rotation on the original G80).
- Concurrency fix when clearing compression tags.
- Fixes DP link training issues on GP102/4/6.
- Fixes backlight handling in the presence of Apple GMUX.
- Improvements to GPU error recovery in a number of scenarios.
- GP106 support.

* 'linux-4.10' of git://github.com/skeggsb/linux:
  drm/nouveau/kms/nv50: fix atomic regression on original G80
  drm/nouveau/bl: Do not register interface if Apple GMUX detected
  drm/nouveau/bl: Assign different names to interfaces
  drm/nouveau/bios/dp: fix handling of LevelEntryTableIndex on DP table 4.2
  drm/nouveau/ltc: protect clearing of comptags with mutex
  drm/nouveau/gr/gf100-: handle GPC/TPC/MPC trap
  drm/nouveau/core: recognise GP106 chipset
  drm/nouveau/ttm: wait for bo fence to signal before unmapping vmas
  drm/nouveau/gr/gf100-: FECS intr handling is not relevant on proprietary ucode
  drm/nouveau/gr/gf100-: properly ack all FECS error interrupts
  drm/nouveau/fifo/gf100-: recover from host mmu faults

14 files changed, 171 insertions, 38 deletions

diff --git a/drivers/gpu/drm/nouveau/nouveau_backlight.c b/drivers/gpu/drm/nouveau/nouveau_backlight.c
index 5e2c5685b4dd..8b1ca4add2ed 100644
--- a/drivers/gpu/drm/nouveau/nouveau_backlight.c
+++ b/drivers/gpu/drm/nouveau/nouveau_backlight.c
@@ -30,12 +30,37 @@
  * Register locations derived from NVClock by Roderick Colenbrander
  */
 
+#include <linux/apple-gmux.h>
 #include <linux/backlight.h>
+#include <linux/idr.h>
 
 #include "nouveau_drv.h"
 #include "nouveau_reg.h"
 #include "nouveau_encoder.h"
 
+static struct ida bl_ida;
+#define BL_NAME_SIZE 15 // 12 for name + 2 for digits + 1 for '\0'
+
+struct backlight_connector {
+        struct list_head head;
+        int id;
+};
+
+static bool
+nouveau_get_backlight_name(char backlight_name[BL_NAME_SIZE], struct backlight_connector
+                *connector)
+{
+        const int nb = ida_simple_get(&bl_ida, 0, 0, GFP_KERNEL);
+        if (nb < 0 || nb >= 100)
+                return false;
+        if (nb > 0)
+                snprintf(backlight_name, BL_NAME_SIZE, "nv_backlight%d", nb);
+        else
+                snprintf(backlight_name, BL_NAME_SIZE, "nv_backlight");
+        connector->id = nb;
+        return true;
+}
+
 static int
 nv40_get_intensity(struct backlight_device *bd)
 {
@@ -74,6 +99,8 @@ nv40_backlight_init(struct drm_connector *connector)
         struct nvif_object *device = &drm->device.object;
         struct backlight_properties props;
         struct backlight_device *bd;
+        struct backlight_connector bl_connector;
+        char backlight_name[BL_NAME_SIZE];
 
         if (!(nvif_rd32(device, NV40_PMC_BACKLIGHT) & NV40_PMC_BACKLIGHT_MASK))
                 return 0;
@@ -81,10 +108,19 @@ nv40_backlight_init(struct drm_connector *connector)
         memset(&props, 0, sizeof(struct backlight_properties));
         props.type = BACKLIGHT_RAW;
         props.max_brightness = 31;
-        bd = backlight_device_register("nv_backlight", connector->kdev, drm,
+        if (!nouveau_get_backlight_name(backlight_name, &bl_connector)) {
+                NV_ERROR(drm, "Failed to retrieve a unique name for the backlight interface\n");
+                return 0;
+        }
+        bd = backlight_device_register(backlight_name , connector->kdev, drm,
                                        &nv40_bl_ops, &props);
-        if (IS_ERR(bd))
+
+        if (IS_ERR(bd)) {
+                if (bl_connector.id > 0)
+                        ida_simple_remove(&bl_ida, bl_connector.id);
                 return PTR_ERR(bd);
+        }
+        list_add(&bl_connector.head, &drm->bl_connectors);
         drm->backlight = bd;
         bd->props.brightness = nv40_get_intensity(bd);
         backlight_update_status(bd);
@@ -182,6 +218,8 @@ nv50_backlight_init(struct drm_connector *connector)
         struct backlight_properties props;
         struct backlight_device *bd;
         const struct backlight_ops *ops;
+        struct backlight_connector bl_connector;
+        char backlight_name[BL_NAME_SIZE];
 
         nv_encoder = find_encoder(connector, DCB_OUTPUT_LVDS);
         if (!nv_encoder) {
@@ -203,11 +241,20 @@ nv50_backlight_init(struct drm_connector *connector)
         memset(&props, 0, sizeof(struct backlight_properties));
         props.type = BACKLIGHT_RAW;
         props.max_brightness = 100;
-        bd = backlight_device_register("nv_backlight", connector->kdev,
+        if (!nouveau_get_backlight_name(backlight_name, &bl_connector)) {
+                NV_ERROR(drm, "Failed to retrieve a unique name for the backlight interface\n");
+                return 0;
+        }
+        bd = backlight_device_register(backlight_name , connector->kdev,
                                        nv_encoder, ops, &props);
-        if (IS_ERR(bd))
+
+        if (IS_ERR(bd)) {
+                if (bl_connector.id > 0)
+                        ida_simple_remove(&bl_ida, bl_connector.id);
                 return PTR_ERR(bd);
+        }
 
+        list_add(&bl_connector.head, &drm->bl_connectors);
         drm->backlight = bd;
         bd->props.brightness = bd->ops->get_brightness(bd);
         backlight_update_status(bd);
@@ -221,6 +268,13 @@ nouveau_backlight_init(struct drm_device *dev)
         struct nvif_device *device = &drm->device;
         struct drm_connector *connector;
 
+        if (apple_gmux_present()) {
+                NV_INFO(drm, "Apple GMUX detected: not registering Nouveau backlight interface\n");
+                return 0;
+        }
+
+        INIT_LIST_HEAD(&drm->bl_connectors);
+
         list_for_each_entry(connector, &dev->mode_config.connector_list, head) {
                 if (connector->connector_type != DRM_MODE_CONNECTOR_LVDS &&
                     connector->connector_type != DRM_MODE_CONNECTOR_eDP)
@@ -247,9 +301,27 @@ void
 nouveau_backlight_exit(struct drm_device *dev)
 {
         struct nouveau_drm *drm = nouveau_drm(dev);
+        struct backlight_connector *connector;
+
+        list_for_each_entry(connector, &drm->bl_connectors, head) {
+                if (connector->id >= 0)
+                        ida_simple_remove(&bl_ida, connector->id);
+        }
 
         if (drm->backlight) {
                 backlight_device_unregister(drm->backlight);
                 drm->backlight = NULL;
         }
 }
+
+void
+nouveau_backlight_ctor(void)
+{
+        ida_init(&bl_ida);
+}
+
+void
+nouveau_backlight_dtor(void)
+{
+        ida_destroy(&bl_ida);
+}
diff --git a/drivers/gpu/drm/nouveau/nouveau_bo.c b/drivers/gpu/drm/nouveau/nouveau_bo.c
index e0c0007689e5..dd07ca140d12 100644
--- a/drivers/gpu/drm/nouveau/nouveau_bo.c
+++ b/drivers/gpu/drm/nouveau/nouveau_bo.c
@@ -1209,6 +1209,7 @@ nouveau_bo_move_ntfy(struct ttm_buffer_object *bo, struct ttm_mem_reg *new_mem)
                                nvbo->page_shift != vma->vm->mmu->lpg_shift)) {
                         nvkm_vm_map(vma, new_mem->mm_node);
                 } else {
+                        WARN_ON(ttm_bo_wait(bo, false, false));
                         nvkm_vm_unmap(vma);
                 }
         }
diff --git a/drivers/gpu/drm/nouveau/nouveau_display.h b/drivers/gpu/drm/nouveau/nouveau_display.h
index 330fe0fc5c11..4a75df06c139 100644
--- a/drivers/gpu/drm/nouveau/nouveau_display.h
+++ b/drivers/gpu/drm/nouveau/nouveau_display.h
@@ -91,6 +91,8 @@ int nouveau_crtc_set_config(struct drm_mode_set *set);
 #ifdef CONFIG_DRM_NOUVEAU_BACKLIGHT
 extern int nouveau_backlight_init(struct drm_device *);
 extern void nouveau_backlight_exit(struct drm_device *);
+extern void nouveau_backlight_ctor(void);
+extern void nouveau_backlight_dtor(void);
 #else
 static inline int
 nouveau_backlight_init(struct drm_device *dev)
@@ -101,6 +103,14 @@ nouveau_backlight_init(struct drm_device *dev)
 static inline void
 nouveau_backlight_exit(struct drm_device *dev) {
 }
+
+static inline void
+nouveau_backlight_ctor(void) {
+}
+
+static inline void
+nouveau_backlight_dtor(void) {
+}
 #endif
 
 struct drm_framebuffer *
diff --git a/drivers/gpu/drm/nouveau/nouveau_drm.c b/drivers/gpu/drm/nouveau/nouveau_drm.c
index 064a925ed69a..59348fc41c77 100644
--- a/drivers/gpu/drm/nouveau/nouveau_drm.c
+++ b/drivers/gpu/drm/nouveau/nouveau_drm.c
@@ -1122,6 +1122,7 @@ nouveau_drm_init(void)
 #endif
 
         nouveau_register_dsm_handler();
+        nouveau_backlight_ctor();
         return drm_pci_init(&driver_pci, &nouveau_drm_pci_driver);
 }
 
@@ -1132,6 +1133,7 @@ nouveau_drm_exit(void)
                 return;
 
         drm_pci_exit(&driver_pci, &nouveau_drm_pci_driver);
+        nouveau_backlight_dtor();
         nouveau_unregister_dsm_handler();
 
 #ifdef CONFIG_NOUVEAU_PLATFORM_DRIVER
diff --git a/drivers/gpu/drm/nouveau/nouveau_drv.h b/drivers/gpu/drm/nouveau/nouveau_drv.h
index 9730c0ef6c6a..8d5ed5bfdacb 100644
--- a/drivers/gpu/drm/nouveau/nouveau_drv.h
+++ b/drivers/gpu/drm/nouveau/nouveau_drv.h
@@ -163,6 +163,7 @@ struct nouveau_drm {
         struct nvbios vbios;
         struct nouveau_display *display;
         struct backlight_device *backlight;
+        struct list_head bl_connectors;
         struct work_struct hpd_work;
 #ifdef CONFIG_ACPI
         struct notifier_block acpi_nb;
diff --git a/drivers/gpu/drm/nouveau/nv50_display.c b/drivers/gpu/drm/nouveau/nv50_display.c
index 7a1aa9161982..2c2c64507661 100644
--- a/drivers/gpu/drm/nouveau/nv50_display.c
+++ b/drivers/gpu/drm/nouveau/nv50_display.c
@@ -1726,6 +1726,11 @@ nv50_head_core_set(struct nv50_head *head, struct nv50_head_atom *asyh)
                         evo_data(push, asyh->core.handle);
                         evo_mthd(push, 0x08c0 + head->base.index * 0x400, 1);
                         evo_data(push, (asyh->core.y << 16) | asyh->core.x);
+                        /* EVO will complain with INVALID_STATE if we have an
+                         * active cursor and (re)specify HeadSetContextDmaIso
+                         * without also updating HeadSetOffsetCursor.
+                         */
+                        asyh->set.curs = asyh->curs.visible;
                 } else
                 if (core->base.user.oclass < GF110_DISP_CORE_CHANNEL_DMA) {
                         evo_mthd(push, 0x0860 + head->base.index * 0x400, 1);
diff --git a/drivers/gpu/drm/nouveau/nvkm/engine/device/base.c b/drivers/gpu/drm/nouveau/nvkm/engine/device/base.c
index 2cbcffe78c3e..cceda959b47c 100644
--- a/drivers/gpu/drm/nouveau/nvkm/engine/device/base.c
+++ b/drivers/gpu/drm/nouveau/nvkm/engine/device/base.c
@@ -2241,6 +2241,35 @@ nv134_chipset = {
         .fifo = gp100_fifo_new,
 };
 
+static const struct nvkm_device_chip
+nv136_chipset = {
+        .name = "GP106",
+        .bar = gf100_bar_new,
+        .bios = nvkm_bios_new,
+        .bus = gf100_bus_new,
+        .devinit = gm200_devinit_new,
+        .fb = gp102_fb_new,
+        .fuse = gm107_fuse_new,
+        .gpio = gk104_gpio_new,
+        .i2c = gm200_i2c_new,
+        .ibus = gm200_ibus_new,
+        .imem = nv50_instmem_new,
+        .ltc = gp100_ltc_new,
+        .mc = gp100_mc_new,
+        .mmu = gf100_mmu_new,
+        .pci = gp100_pci_new,
+        .pmu = gp102_pmu_new,
+        .timer = gk20a_timer_new,
+        .top = gk104_top_new,
+        .ce[0] = gp102_ce_new,
+        .ce[1] = gp102_ce_new,
+        .ce[2] = gp102_ce_new,
+        .ce[3] = gp102_ce_new,
+        .disp = gp102_disp_new,
+        .dma = gf119_dma_new,
+        .fifo = gp100_fifo_new,
+};
+
 static int
 nvkm_device_event_ctor(struct nvkm_object *object, void *data, u32 size,
                        struct nvkm_notify *notify)
@@ -2677,6 +2706,7 @@ nvkm_device_ctor(const struct nvkm_device_func *func,
                 case 0x130: device->chip = &nv130_chipset; break;
                 case 0x132: device->chip = &nv132_chipset; break;
                 case 0x134: device->chip = &nv134_chipset; break;
+                case 0x136: device->chip = &nv136_chipset; break;
                 default:
                         nvdev_error(device, "unknown chipset (%08x)\n", boot0);
                         goto done;
diff --git a/drivers/gpu/drm/nouveau/nvkm/engine/fifo/gf100.c b/drivers/gpu/drm/nouveau/nvkm/engine/fifo/gf100.c
index 352a0baec84d..ec68ea9747d5 100644
--- a/drivers/gpu/drm/nouveau/nvkm/engine/fifo/gf100.c
+++ b/drivers/gpu/drm/nouveau/nvkm/engine/fifo/gf100.c
@@ -180,7 +180,8 @@ gf100_fifo_recover(struct gf100_fifo *fifo, struct nvkm_engine *engine,
         list_del_init(&chan->head);
         chan->killed = true;
 
-        fifo->recover.mask |= 1ULL << engine->subdev.index;
+        if (engine != &fifo->base.engine)
+                fifo->recover.mask |= 1ULL << engine->subdev.index;
         schedule_work(&fifo->recover.work);
 }
 
diff --git a/drivers/gpu/drm/nouveau/nvkm/engine/fifo/gk104.c b/drivers/gpu/drm/nouveau/nvkm/engine/fifo/gk104.c
index 103c0afaaa6d..38c0910722c0 100644
--- a/drivers/gpu/drm/nouveau/nvkm/engine/fifo/gk104.c
+++ b/drivers/gpu/drm/nouveau/nvkm/engine/fifo/gk104.c
@@ -743,14 +743,14 @@ gk104_fifo_fault_engine[] = {
         { 0x04, "BAR1", NULL, NVKM_SUBDEV_BAR },
         { 0x05, "BAR2", NULL, NVKM_SUBDEV_INSTMEM },
         { 0x06, "SCHED" },
-        { 0x07, "HOST0" },
-        { 0x08, "HOST1" },
-        { 0x09, "HOST2" },
-        { 0x0a, "HOST3" },
-        { 0x0b, "HOST4" },
-        { 0x0c, "HOST5" },
-        { 0x0d, "HOST6" },
-        { 0x0e, "HOST7" },
+        { 0x07, "HOST0", NULL, NVKM_ENGINE_FIFO },
+        { 0x08, "HOST1", NULL, NVKM_ENGINE_FIFO },
+        { 0x09, "HOST2", NULL, NVKM_ENGINE_FIFO },
+        { 0x0a, "HOST3", NULL, NVKM_ENGINE_FIFO },
+        { 0x0b, "HOST4", NULL, NVKM_ENGINE_FIFO },
+        { 0x0c, "HOST5", NULL, NVKM_ENGINE_FIFO },
+        { 0x0d, "HOST6", NULL, NVKM_ENGINE_FIFO },
+        { 0x0e, "HOST7", NULL, NVKM_ENGINE_FIFO },
         { 0x0f, "HOSTSR" },
         { 0x10, "MSVLD", NULL, NVKM_ENGINE_MSVLD },
         { 0x11, "MSPPP", NULL, NVKM_ENGINE_MSPPP },
diff --git a/drivers/gpu/drm/nouveau/nvkm/engine/fifo/gm107.c b/drivers/gpu/drm/nouveau/nvkm/engine/fifo/gm107.c
index bd1ff877aa06..29c080683b32 100644
--- a/drivers/gpu/drm/nouveau/nvkm/engine/fifo/gm107.c
+++ b/drivers/gpu/drm/nouveau/nvkm/engine/fifo/gm107.c
@@ -32,14 +32,14 @@ gm107_fifo_fault_engine[] = {
         { 0x04, "BAR1", NULL, NVKM_SUBDEV_BAR },
         { 0x05, "BAR2", NULL, NVKM_SUBDEV_INSTMEM },
         { 0x06, "SCHED" },
-        { 0x07, "HOST0" },
-        { 0x08, "HOST1" },
-        { 0x09, "HOST2" },
-        { 0x0a, "HOST3" },
-        { 0x0b, "HOST4" },
-        { 0x0c, "HOST5" },
-        { 0x0d, "HOST6" },
-        { 0x0e, "HOST7" },
+        { 0x07, "HOST0", NULL, NVKM_ENGINE_FIFO },
+        { 0x08, "HOST1", NULL, NVKM_ENGINE_FIFO },
+        { 0x09, "HOST2", NULL, NVKM_ENGINE_FIFO },
+        { 0x0a, "HOST3", NULL, NVKM_ENGINE_FIFO },
+        { 0x0b, "HOST4", NULL, NVKM_ENGINE_FIFO },
+        { 0x0c, "HOST5", NULL, NVKM_ENGINE_FIFO },
+        { 0x0d, "HOST6", NULL, NVKM_ENGINE_FIFO },
+        { 0x0e, "HOST7", NULL, NVKM_ENGINE_FIFO },
         { 0x0f, "HOSTSR" },
         { 0x13, "PERF" },
         { 0x17, "PMU" },
diff --git a/drivers/gpu/drm/nouveau/nvkm/engine/fifo/gp100.c b/drivers/gpu/drm/nouveau/nvkm/engine/fifo/gp100.c
index eff83f7fb705..b2635aea9f6e 100644
--- a/drivers/gpu/drm/nouveau/nvkm/engine/fifo/gp100.c
+++ b/drivers/gpu/drm/nouveau/nvkm/engine/fifo/gp100.c
@@ -30,17 +30,17 @@ gp100_fifo_fault_engine[] = {
         { 0x03, "IFB", NULL, NVKM_ENGINE_IFB },
         { 0x04, "BAR1", NULL, NVKM_SUBDEV_BAR },
         { 0x05, "BAR2", NULL, NVKM_SUBDEV_INSTMEM },
-        { 0x06, "HOST0" },
-        { 0x07, "HOST1" },
-        { 0x08, "HOST2" },
-        { 0x09, "HOST3" },
-        { 0x0a, "HOST4" },
-        { 0x0b, "HOST5" },
-        { 0x0c, "HOST6" },
-        { 0x0d, "HOST7" },
-        { 0x0e, "HOST8" },
-        { 0x0f, "HOST9" },
-        { 0x10, "HOST10" },
+        { 0x06, "HOST0", NULL, NVKM_ENGINE_FIFO },
+        { 0x07, "HOST1", NULL, NVKM_ENGINE_FIFO },
+        { 0x08, "HOST2", NULL, NVKM_ENGINE_FIFO },
+        { 0x09, "HOST3", NULL, NVKM_ENGINE_FIFO },
+        { 0x0a, "HOST4", NULL, NVKM_ENGINE_FIFO },
+        { 0x0b, "HOST5", NULL, NVKM_ENGINE_FIFO },
+        { 0x0c, "HOST6", NULL, NVKM_ENGINE_FIFO },
+        { 0x0d, "HOST7", NULL, NVKM_ENGINE_FIFO },
+        { 0x0e, "HOST8", NULL, NVKM_ENGINE_FIFO },
+        { 0x0f, "HOST9", NULL, NVKM_ENGINE_FIFO },
+        { 0x10, "HOST10", NULL, NVKM_ENGINE_FIFO },
         { 0x13, "PERF" },
         { 0x17, "PMU" },
         { 0x18, "PTP" },
diff --git a/drivers/gpu/drm/nouveau/nvkm/engine/gr/gf100.c b/drivers/gpu/drm/nouveau/nvkm/engine/gr/gf100.c
index 60a1b5c8214b..f65a5b0a1a4d 100644
--- a/drivers/gpu/drm/nouveau/nvkm/engine/gr/gf100.c
+++ b/drivers/gpu/drm/nouveau/nvkm/engine/gr/gf100.c
@@ -1041,6 +1041,13 @@ gf100_gr_trap_tpc(struct gf100_gr *gr, int gpc, int tpc)
                 stat &= ~0x00000008;
         }
 
+        if (stat & 0x00000010) {
+                u32 trap = nvkm_rd32(device, TPC_UNIT(gpc, tpc, 0x0430));
+                nvkm_error(subdev, "GPC%d/TPC%d/MPC: %08x\n", gpc, tpc, trap);
+                nvkm_wr32(device, TPC_UNIT(gpc, tpc, 0x0430), 0xc0000000);
+                stat &= ~0x00000010;
+        }
+
         if (stat) {
                 nvkm_error(subdev, "GPC%d/TPC%d/%08x: unknown\n", gpc, tpc, stat);
         }
@@ -1258,7 +1265,7 @@ gf100_gr_ctxctl_isr(struct gf100_gr *gr)
         struct nvkm_device *device = subdev->device;
         u32 stat = nvkm_rd32(device, 0x409c18);
 
-        if (stat & 0x00000001) {
+        if (!gr->firmware && (stat & 0x00000001)) {
                 u32 code = nvkm_rd32(device, 0x409814);
                 if (code == E_BAD_FWMTHD) {
                         u32 class = nvkm_rd32(device, 0x409808);
@@ -1270,15 +1277,14 @@ gf100_gr_ctxctl_isr(struct gf100_gr *gr)
                         nvkm_error(subdev, "FECS MTHD subc %d class %04x "
                                            "mthd %04x data %08x\n",
                                    subc, class, mthd, data);
-
-                        nvkm_wr32(device, 0x409c20, 0x00000001);
-                        stat &= ~0x00000001;
                 } else {
                         nvkm_error(subdev, "FECS ucode error %d\n", code);
                 }
+                nvkm_wr32(device, 0x409c20, 0x00000001);
+                stat &= ~0x00000001;
         }
 
-        if (stat & 0x00080000) {
+        if (!gr->firmware && (stat & 0x00080000)) {
                 nvkm_error(subdev, "FECS watchdog timeout\n");
                 gf100_gr_ctxctl_debug(gr);
                 nvkm_wr32(device, 0x409c20, 0x00080000);
diff --git a/drivers/gpu/drm/nouveau/nvkm/subdev/bios/dp.c b/drivers/gpu/drm/nouveau/nvkm/subdev/bios/dp.c
index d89e78c4e689..972370ed36f0 100644
--- a/drivers/gpu/drm/nouveau/nvkm/subdev/bios/dp.c
+++ b/drivers/gpu/drm/nouveau/nvkm/subdev/bios/dp.c
@@ -207,8 +207,11 @@ nvbios_dpcfg_match(struct nvkm_bios *bios, u16 outp, u8 pc, u8 vs, u8 pe,
         if (*ver >= 0x30) {
                 const u8 vsoff[] = { 0, 4, 7, 9 };
                 idx = (pc * 10) + vsoff[vs] + pe;
-                if (*ver >= 0x40 && *hdr >= 0x12)
+                if (*ver >= 0x40 && *ver <= 0x41 && *hdr >= 0x12)
                         idx += nvbios_rd08(bios, outp + 0x11) * 40;
+                else
+                if (*ver >= 0x42)
+                        idx += nvbios_rd08(bios, outp + 0x11) * 10;
         } else {
                 while ((data = nvbios_dpcfg_entry(bios, outp, ++idx,
                                                   ver, hdr, cnt, len))) {
diff --git a/drivers/gpu/drm/nouveau/nvkm/subdev/ltc/base.c b/drivers/gpu/drm/nouveau/nvkm/subdev/ltc/base.c
index 39c2a38e54f7..0c7ef250dcaf 100644
--- a/drivers/gpu/drm/nouveau/nvkm/subdev/ltc/base.c
+++ b/drivers/gpu/drm/nouveau/nvkm/subdev/ltc/base.c
@@ -47,8 +47,10 @@ nvkm_ltc_tags_clear(struct nvkm_ltc *ltc, u32 first, u32 count)
 
         BUG_ON((first > limit) || (limit >= ltc->num_tags));
 
+        mutex_lock(&ltc->subdev.mutex);
         ltc->func->cbc_clear(ltc, first, limit);
         ltc->func->cbc_wait(ltc);
+        mutex_unlock(&ltc->subdev.mutex);
 }
 
 int