3 files changed, 77 insertions, 13 deletions

diff --git a/drivers/gpu/nvgpu/gk20a/channel_gk20a.c b/drivers/gpu/nvgpu/gk20a/channel_gk20a.c
index 1cc0f154..90b7489c 100644
--- a/drivers/gpu/nvgpu/gk20a/channel_gk20a.c
+++ b/drivers/gpu/nvgpu/gk20a/channel_gk20a.c
@@ -697,10 +697,16 @@ int gk20a_channel_release(struct inode *inode, struct file *filp)
 {
         struct channel_gk20a *ch = (struct channel_gk20a *)filp->private_data;
         struct gk20a *g = ch->g;
+        int err;
 
         trace_gk20a_channel_release(dev_name(&g->dev->dev));
 
-        gk20a_channel_busy(ch->g->dev);
+        err = gk20a_channel_busy(ch->g->dev);
+        if (err) {
+                gk20a_err(dev_from_gk20a(g), "failed to release channel %d",
+                        ch->hw_chid);
+                return err;
+        }
         gk20a_free_channel(ch, true);
         gk20a_channel_idle(ch->g->dev);
 
@@ -1422,7 +1428,7 @@ static int gk20a_submit_channel_gpfifo(struct channel_gk20a *c,
 {
         struct gk20a *g = c->g;
         struct device *d = dev_from_gk20a(g);
-        u32 err = 0;
+        int err = 0;
         int i;
         struct priv_cmd_entry *wait_cmd = NULL;
         struct priv_cmd_entry *incr_cmd = NULL;
@@ -1453,7 +1459,11 @@ static int gk20a_submit_channel_gpfifo(struct channel_gk20a *c,
         gk20a_dbg_info("channel %d", c->hw_chid);
 
         /* gk20a_channel_update releases this ref. */
-        gk20a_channel_busy(g->dev);
+        err = gk20a_channel_busy(g->dev);
+        if (err) {
+                gk20a_err(d, "failed to host gk20a to submit gpfifo");
+                return err;
+        }
 
         trace_gk20a_channel_submit_gpfifo(c->g->dev->name,
                                           c->hw_chid,
@@ -2031,19 +2041,37 @@ long gk20a_channel_ioctl(struct file *filp,
         case NVHOST_IOCTL_CHANNEL_SET_NVMAP_FD:
                 break;
         case NVHOST_IOCTL_CHANNEL_ALLOC_OBJ_CTX:
-                gk20a_channel_busy(dev);
+                err = gk20a_channel_busy(dev);
+                if (err) {
+                        dev_err(&dev->dev,
+                                "%s: failed to host gk20a for ioctl cmd: 0x%x",
+                                __func__, cmd);
+                        return err;
+                }
                 err = gk20a_alloc_obj_ctx(ch,
                                 (struct nvhost_alloc_obj_ctx_args *)buf);
                 gk20a_channel_idle(dev);
                 break;
         case NVHOST_IOCTL_CHANNEL_FREE_OBJ_CTX:
-                gk20a_channel_busy(dev);
+                err = gk20a_channel_busy(dev);
+                if (err) {
+                        dev_err(&dev->dev,
+                                "%s: failed to host gk20a for ioctl cmd: 0x%x",
+                                __func__, cmd);
+                        return err;
+                }
                 err = gk20a_free_obj_ctx(ch,
                                 (struct nvhost_free_obj_ctx_args *)buf);
                 gk20a_channel_idle(dev);
                 break;
         case NVHOST_IOCTL_CHANNEL_ALLOC_GPFIFO:
-                gk20a_channel_busy(dev);
+                err = gk20a_channel_busy(dev);
+                if (err) {
+                        dev_err(&dev->dev,
+                                "%s: failed to host gk20a for ioctl cmd: 0x%x",
+                                __func__, cmd);
+                        return err;
+                }
                 err = gk20a_alloc_channel_gpfifo(ch,
                                 (struct nvhost_alloc_gpfifo_args *)buf);
                 gk20a_channel_idle(dev);
@@ -2053,26 +2081,50 @@ long gk20a_channel_ioctl(struct file *filp,
                                 (struct nvhost_submit_gpfifo_args *)buf);
                 break;
         case NVHOST_IOCTL_CHANNEL_WAIT:
-                gk20a_channel_busy(dev);
+                err = gk20a_channel_busy(dev);
+                if (err) {
+                        dev_err(&dev->dev,
+                                "%s: failed to host gk20a for ioctl cmd: 0x%x",
+                                __func__, cmd);
+                        return err;
+                }
                 err = gk20a_channel_wait(ch,
                                 (struct nvhost_wait_args *)buf);
                 gk20a_channel_idle(dev);
                 break;
         case NVHOST_IOCTL_CHANNEL_ZCULL_BIND:
-                gk20a_channel_busy(dev);
+                err = gk20a_channel_busy(dev);
+                if (err) {
+                        dev_err(&dev->dev,
+                                "%s: failed to host gk20a for ioctl cmd: 0x%x",
+                                __func__, cmd);
+                        return err;
+                }
                 err = gk20a_channel_zcull_bind(ch,
                                 (struct nvhost_zcull_bind_args *)buf);
                 gk20a_channel_idle(dev);
                 break;
         case NVHOST_IOCTL_CHANNEL_SET_ERROR_NOTIFIER:
-                gk20a_channel_busy(dev);
+                err = gk20a_channel_busy(dev);
+                if (err) {
+                        dev_err(&dev->dev,
+                                "%s: failed to host gk20a for ioctl cmd: 0x%x",
+                                __func__, cmd);
+                        return err;
+                }
                 err = gk20a_init_error_notifier(ch,
                                 (struct nvhost_set_error_notifier *)buf);
                 gk20a_channel_idle(dev);
                 break;
 #ifdef CONFIG_GK20A_CYCLE_STATS
         case NVHOST_IOCTL_CHANNEL_CYCLE_STATS:
-                gk20a_channel_busy(dev);
+                err = gk20a_channel_busy(dev);
+                if (err) {
+                        dev_err(&dev->dev,
+                                "%s: failed to host gk20a for ioctl cmd: 0x%x",
+                                __func__, cmd);
+                        return err;
+                }
                 err = gk20a_channel_cycle_stats(ch,
                                 (struct nvhost_cycle_stats_args *)buf);
                 gk20a_channel_idle(dev);
@@ -2105,7 +2157,13 @@ long gk20a_channel_ioctl(struct file *filp,
                         ch->has_timedout;
                 break;
         case NVHOST_IOCTL_CHANNEL_SET_PRIORITY:
-                gk20a_channel_busy(dev);
+                err = gk20a_channel_busy(dev);
+                if (err) {
+                        dev_err(&dev->dev,
+                                "%s: failed to host gk20a for ioctl cmd: 0x%x",
+                                __func__, cmd);
+                        return err;
+                }
                 gk20a_channel_set_priority(ch,
                         ((struct nvhost_set_priority_args *)buf)->priority);
                 gk20a_channel_idle(dev);
diff --git a/drivers/gpu/nvgpu/gk20a/dbg_gpu_gk20a.c b/drivers/gpu/nvgpu/gk20a/dbg_gpu_gk20a.c
index da7d733e..bc5dc4c1 100644
--- a/drivers/gpu/nvgpu/gk20a/dbg_gpu_gk20a.c
+++ b/drivers/gpu/nvgpu/gk20a/dbg_gpu_gk20a.c
@@ -555,7 +555,9 @@ static int dbg_set_powergate(struct dbg_session_gk20a *dbg_s,
 
                         gk20a_dbg(gpu_dbg_gpu_dbg | gpu_dbg_fn, "module busy");
                         gk20a_busy(g->dev);
-                        gk20a_channel_busy(dbg_s->pdev);
+                        err = gk20a_channel_busy(dbg_s->pdev);
+                        if (err)
+                                return -EPERM;
 
                         g->ops.clock_gating.slcg_gr_load_gating_prod(g,
                                         false);
diff --git a/drivers/gpu/nvgpu/gk20a/gk20a_sysfs.c b/drivers/gpu/nvgpu/gk20a/gk20a_sysfs.c
index f6b43f50..14629fbe 100644
--- a/drivers/gpu/nvgpu/gk20a/gk20a_sysfs.c
+++ b/drivers/gpu/nvgpu/gk20a/gk20a_sysfs.c
@@ -268,6 +268,7 @@ static ssize_t elpg_enable_store(struct device *device,
         struct platform_device *ndev = to_platform_device(device);
         struct gk20a *g = get_gk20a(ndev);
         unsigned long val = 0;
+        int err;
 
         if (kstrtoul(buf, 10, &val) < 0)
                 return -EINVAL;
@@ -276,7 +277,10 @@ static ssize_t elpg_enable_store(struct device *device,
          * Since elpg is refcounted, we should not unnecessarily call
          * enable/disable if it is already so.
          */
-        gk20a_channel_busy(g->dev);
+        err = gk20a_channel_busy(g->dev);
+        if (err)
+                return -EAGAIN;
+
         if (val && !g->elpg_enabled) {
                 g->elpg_enabled = true;
                 gk20a_pmu_enable_elpg(g);