gpu: nvgpu: take power refcount in gk20a_cde_convert()

We have a gk20a_busy() call in gk20a_buffer_convert_gpu_to_cde()
and we again call gk20a_busy() in gk20a_submit_channel_gpfifo()

If gk20a_do_idle() is triggered in between these two calls,
then this leads to a deadlock and results in idle failure

Hence to avoid this take power refcount in a more fine-grained
way i.e. in gk20a_cde_convert() instead of taking in
gk20a_buffer_convert_gpu_to_cde()

Keep gk20a_cde_execute_buffer() out of the gk20a_busy()/
gk20a_idle() pair since we take power refcount in submit path
anyways

Add correct error handling path in gk20a_cde_convert()

Bug 200287073

Change-Id: Iffea2d4c03f42b47dbf05e7fe8fe2994f9c6b37c
Signed-off-by: Deepak Nibade <dnibade@nvidia.com>
Reviewed-on: http://git-master/r/1324329
(cherry picked from commit ce057d784d40a6ce57e892d58e211ed2fd9826f8)
Reviewed-on: http://git-master/r/1320408
Reviewed-by: mobile promotions <svcmobile_promotions@nvidia.com>
Tested-by: mobile promotions <svcmobile_promotions@nvidia.com>

1 files changed, 25 insertions, 19 deletions

diff --git a/drivers/gpu/nvgpu/gk20a/cde_gk20a.c b/drivers/gpu/nvgpu/gk20a/cde_gk20a.c
index 8f9d7831..df15cf51 100644
--- a/drivers/gpu/nvgpu/gk20a/cde_gk20a.c
+++ b/drivers/gpu/nvgpu/gk20a/cde_gk20a.c
@@ -949,12 +949,16 @@ __releases(&cde_app->mutex)
             scatterbuffer_byte_offset < compbits_byte_offset)
                 return -EINVAL;
 
+        err = gk20a_busy(g->dev);
+        if (err)
+                return err;
+
         nvgpu_mutex_acquire(&g->cde_app.mutex);
         cde_ctx = gk20a_cde_get_context(g);
         nvgpu_mutex_release(&g->cde_app.mutex);
         if (IS_ERR(cde_ctx)) {
                 err = PTR_ERR(cde_ctx);
-                goto exit_unlock;
+                goto exit_idle;
         }
 
         /* First, map the buffer to local va */
@@ -962,7 +966,7 @@ __releases(&cde_app->mutex)
         /* ensure that the compbits buffer has drvdata */
         err = gk20a_dmabuf_alloc_drvdata(compbits_scatter_buf, g->dev);
         if (err)
-                goto exit_unlock;
+                goto exit_idle;
 
         /* compbits don't start at page aligned offset, so we need to align
            the region to be mapped */
@@ -1005,7 +1009,7 @@ __releases(&cde_app->mutex)
         if (!map_vaddr) {
                 dma_buf_put(compbits_scatter_buf);
                 err = -EINVAL;
-                goto exit_unlock;
+                goto exit_idle;
         }
 
         if (scatterbuffer_byte_offset &&
@@ -1019,7 +1023,7 @@ __releases(&cde_app->mutex)
                         gk20a_warn(g->dev,
                                    "dma_buf_vmap failed");
                         err = -EINVAL;
-                        goto exit_unlock;
+                        goto exit_unmap_vaddr;
                 }
 
                 scatter_buffer = surface + scatterbuffer_byte_offset;
@@ -1031,7 +1035,7 @@ __releases(&cde_app->mutex)
                         gk20a_warn(g->dev,
                                    "mm_pin failed");
                         err = -EINVAL;
-                        goto exit_unlock;
+                        goto exit_unmap_surface;
                 } else {
                         err = g->ops.cde.populate_scatter_buffer(g, sgt,
                                         compbits_byte_offset, scatter_buffer,
@@ -1041,7 +1045,7 @@ __releases(&cde_app->mutex)
                         gk20a_mm_unpin(g->dev, compbits_scatter_buf,
                                        sgt);
                         if (err)
-                                goto exit_unlock;
+                                goto exit_unmap_surface;
                 }
 
                 __cpuc_flush_dcache_area(scatter_buffer, scatterbuffer_size);
@@ -1078,7 +1082,7 @@ __releases(&cde_app->mutex)
                 if (id < 0 || id >= MAX_CDE_USER_PARAMS) {
                         gk20a_warn(cde_ctx->dev, "cde: unknown user parameter");
                         err = -EINVAL;
-                        goto exit_unlock;
+                        goto exit_unmap_surface;
                 }
                 cde_ctx->user_param_values[id] = param->value;
         }
@@ -1087,7 +1091,7 @@ __releases(&cde_app->mutex)
         err = gk20a_cde_patch_params(cde_ctx);
         if (err) {
                 gk20a_warn(cde_ctx->dev, "cde: failed to patch parameters");
-                goto exit_unlock;
+                goto exit_unmap_surface;
         }
 
         gk20a_dbg(gpu_dbg_cde, "cde: buffer=cbc, size=%zu, gpuva=%llx\n",
@@ -1097,11 +1101,13 @@ __releases(&cde_app->mutex)
         gk20a_dbg(gpu_dbg_cde, "cde: buffer=scatterbuffer, size=%llu, gpuva=%llx\n",
                  cde_ctx->scatterbuffer_size, cde_ctx->scatterbuffer_vaddr);
 
-
         /* take always the postfence as it is needed for protecting the
          * cde context */
         flags = __flags | NVGPU_SUBMIT_GPFIFO_FLAGS_FENCE_GET;
 
+        /* gk20a_cde_execute_buffer() will grab a power reference of it's own */
+        gk20a_idle(g->dev);
+
         /* execute the conversion buffer, combined with init first if it's the
          * first time */
         err = gk20a_cde_execute_buffer(cde_ctx,
@@ -1112,16 +1118,21 @@ __releases(&cde_app->mutex)
 
         cde_ctx->init_cmd_executed = true;
 
-exit_unlock:
-
         /* unmap the buffers - channel holds references to them now */
-        if (map_vaddr)
-                gk20a_vm_unmap(cde_ctx->vm, map_vaddr);
-
         if (surface)
                 dma_buf_vunmap(compbits_scatter_buf, surface);
+        gk20a_vm_unmap(cde_ctx->vm, map_vaddr);
 
         return err;
+
+exit_unmap_surface:
+        if (surface)
+                dma_buf_vunmap(compbits_scatter_buf, surface);
+exit_unmap_vaddr:
+        gk20a_vm_unmap(cde_ctx->vm, map_vaddr);
+exit_idle:
+        gk20a_idle(g->dev);
+        return err;
 }
 
 static void gk20a_cde_finished_ctx_cb(struct channel_gk20a *ch, void *data)
@@ -1520,10 +1531,6 @@ static int gk20a_buffer_convert_gpu_to_cde(
         if (!g->cde_app.initialised)
                 return -ENOSYS;
 
-        err = gk20a_busy(g->dev);
-        if (err)
-                return err;
-
         gk20a_dbg(gpu_dbg_cde, "firmware version = %d\n",
                 g->cde_app.firmware_version);
 
@@ -1539,7 +1546,6 @@ static int gk20a_buffer_convert_gpu_to_cde(
                 err = -EINVAL;
         }
 
-        gk20a_idle(g->dev);
         return err;
 }