gpu: nvgpu: vgpu: fix notification handling

Take a channel ref when handling a notification from
the server, to prevent the channel from being closed.

Also, mark the channel as faulted before calling
g20a_channel_abort, to keep the semantics the same
as the native driver.

Bug 1653186

Change-Id: I0cb8ce7bad22a4d508eade6ff63a412296a02fc9
Signed-off-by: Aingara Paramakuru <aparamakuru@nvidia.com>
Reviewed-on: http://git-master/r/811885
Signed-off-by: Seema Khowala <seemaj@nvidia.com>
Reviewed-on: http://git-master/r/817021
Reviewed-by: Automatic_Commit_Validation_User
GVS: Gerrit_Virtual_Submit
Reviewed-by: Terje Bergstrom <tbergstrom@nvidia.com>

1 files changed, 7 insertions, 2 deletions

diff --git a/drivers/gpu/nvgpu/vgpu/fifo_vgpu.c b/drivers/gpu/nvgpu/vgpu/fifo_vgpu.c
index 84bb3646..a2ecd864 100644
--- a/drivers/gpu/nvgpu/vgpu/fifo_vgpu.c
+++ b/drivers/gpu/nvgpu/vgpu/fifo_vgpu.c
@@ -541,7 +541,11 @@ static void vgpu_fifo_set_ctx_mmu_error(struct gk20a *g,
 int vgpu_fifo_isr(struct gk20a *g, struct tegra_vgpu_fifo_intr_info *info)
 {
         struct fifo_gk20a *f = &g->fifo;
-        struct channel_gk20a *ch = &f->channel[info->chid];
+        struct channel_gk20a *ch = gk20a_channel_get(&f->channel[info->chid]);
+
+        gk20a_dbg_fn("");
+        if (!ch)
+                return 0;
 
         gk20a_err(dev_from_gk20a(g), "fifo intr (%d) on ch %u",
                 info->type, info->chid);
@@ -555,14 +559,15 @@ int vgpu_fifo_isr(struct gk20a *g, struct tegra_vgpu_fifo_intr_info *info)
                                         NVGPU_CHANNEL_FIFO_ERROR_IDLE_TIMEOUT);
                 break;
         case TEGRA_VGPU_FIFO_INTR_MMU_FAULT:
-                gk20a_channel_abort(ch);
                 vgpu_fifo_set_ctx_mmu_error(g, ch);
+                gk20a_channel_abort(ch);
                 break;
         default:
                 WARN_ON(1);
                 break;
         }
 
+        gk20a_channel_put(ch);
         return 0;
 }