gpu: nvgpu: Check bar1 bind

Add two fb flushes after bar1 bind. This should hang the thread instead
of whole system in case there is a BAR1 hang.

Change-Id: I2385a243711219297b889daa30c9fc81106e5825
Signed-off-by: Terje Bergstrom <tbergstrom@nvidia.com>
Reviewed-on: http://git-master/r/390183

1 files changed, 13 insertions, 9 deletions

diff --git a/drivers/gpu/nvgpu/gk20a/mm_gk20a.c b/drivers/gpu/nvgpu/gk20a/mm_gk20a.c
index b22df5e8..208e5291 100644
--- a/drivers/gpu/nvgpu/gk20a/mm_gk20a.c
+++ b/drivers/gpu/nvgpu/gk20a/mm_gk20a.c
@@ -377,13 +377,12 @@ static int gk20a_init_mm_setup_hw(struct gk20a *g)
         inst_pa = (u32)(inst_pa >> bar1_instance_block_shift_gk20a());
         gk20a_dbg_info("bar1 inst block ptr: 0x%08x",  (u32)inst_pa);
 
-        /* this is very early in init... can we defer this? */
-        {
-                gk20a_writel(g, bus_bar1_block_r(),
-                             bus_bar1_block_target_vid_mem_f() |
-                             bus_bar1_block_mode_virtual_f() |
-                             bus_bar1_block_ptr_f(inst_pa));
-        }
+        gk20a_writel(g, bus_bar1_block_r(),
+                     bus_bar1_block_target_vid_mem_f() |
+                     bus_bar1_block_mode_virtual_f() |
+                     bus_bar1_block_ptr_f(inst_pa));
+        if (gk20a_mm_fb_flush(g) || gk20a_mm_fb_flush(g))
+                return -EBUSY;
 
         gk20a_dbg_fn("done");
         return 0;
@@ -2702,11 +2701,12 @@ clean_up:
         return err;
 }
 
-void gk20a_mm_fb_flush(struct gk20a *g)
+int gk20a_mm_fb_flush(struct gk20a *g)
 {
         struct mm_gk20a *mm = &g->mm;
         u32 data;
         s32 retry = 100;
+        int ret = 0;
 
         gk20a_dbg_fn("");
 
@@ -2734,11 +2734,15 @@ void gk20a_mm_fb_flush(struct gk20a *g)
                         break;
         } while (retry >= 0 || !tegra_platform_is_silicon());
 
-        if (retry < 0)
+        if (retry < 0) {
                 gk20a_warn(dev_from_gk20a(g),
                         "fb_flush too many retries");
+                ret = -EBUSY;
+        }
 
         mutex_unlock(&mm->l2_op_lock);
+
+        return ret;
 }
 
 static void gk20a_mm_l2_invalidate_locked(struct gk20a *g)