4 files changed, 24 insertions, 6 deletions

diff --git a/drivers/gpu/nvgpu/common/linux/io.c b/drivers/gpu/nvgpu/common/linux/io.c
index 729825e7..cde90ddd 100644
--- a/drivers/gpu/nvgpu/common/linux/io.c
+++ b/drivers/gpu/nvgpu/common/linux/io.c
@@ -33,6 +33,16 @@ void nvgpu_writel(struct gk20a *g, u32 r, u32 v)
 
 u32 nvgpu_readl(struct gk20a *g, u32 r)
 {
+        u32 v = __nvgpu_readl(g, r);
+
+        if (v == 0xffffffff)
+                __nvgpu_check_gpu_state(g);
+
+        return v;
+}
+
+u32 __nvgpu_readl(struct gk20a *g, u32 r)
+{
         struct nvgpu_os_linux *l = nvgpu_os_linux_from_gk20a(g);
         u32 v = 0xffffffff;
 
@@ -41,8 +51,6 @@ u32 nvgpu_readl(struct gk20a *g, u32 r)
                 gk20a_dbg(gpu_dbg_reg, "r=0x%x v=0x%x (failed)", r, v);
         } else {
                 v = readl(l->regs + r);
-                if (v == 0xffffffff)
-                        __nvgpu_check_gpu_state(g);
                 gk20a_dbg(gpu_dbg_reg, "r=0x%x v=0x%x", r, v);
         }
 
diff --git a/drivers/gpu/nvgpu/gk20a/gk20a.c b/drivers/gpu/nvgpu/gk20a/gk20a.c
index c72b6193..0ccc8f6c 100644
--- a/drivers/gpu/nvgpu/gk20a/gk20a.c
+++ b/drivers/gpu/nvgpu/gk20a/gk20a.c
@@ -54,11 +54,17 @@
 
 void __nvgpu_check_gpu_state(struct gk20a *g)
 {
-        u32 boot_0 = g->ops.mc.boot_0(g, NULL, NULL, NULL);
+        u32 boot_0 = 0xffffffff;
 
+        if (!g->ops.mc.boot_0) {
+                nvgpu_err(g, "Can't determine GPU state, mc.boot_0 unset");
+                return;
+        }
+
+        boot_0 = g->ops.mc.boot_0(g, NULL, NULL, NULL);
         if (boot_0 == 0xffffffff) {
-                pr_err("nvgpu: GPU has disappeared from bus!!\n");
-                pr_err("nvgpu: Rebooting system!!\n");
+                nvgpu_err(g, "GPU has disappeared from bus!!");
+                nvgpu_err(g, "Rebooting system!!");
                 kernel_restart(NULL);
         }
 }
diff --git a/drivers/gpu/nvgpu/gk20a/mc_gk20a.c b/drivers/gpu/nvgpu/gk20a/mc_gk20a.c
index 9d9256bd..5027eaa4 100644
--- a/drivers/gpu/nvgpu/gk20a/mc_gk20a.c
+++ b/drivers/gpu/nvgpu/gk20a/mc_gk20a.c
@@ -200,7 +200,10 @@ void gk20a_mc_reset(struct gk20a *g, u32 units)
 
 u32 gk20a_mc_boot_0(struct gk20a *g, u32 *arch, u32 *impl, u32 *rev)
 {
-        u32 val = gk20a_readl(g, mc_boot_0_r());
+        u32 val = __nvgpu_readl(g, mc_boot_0_r());
+
+        if (val == 0xffffffff)
+                return val;
 
         if (arch)
                 *arch = mc_boot_0_architecture_v(val) <<
diff --git a/drivers/gpu/nvgpu/include/nvgpu/io.h b/drivers/gpu/nvgpu/include/nvgpu/io.h
index 94ae8f95..b7281b41 100644
--- a/drivers/gpu/nvgpu/include/nvgpu/io.h
+++ b/drivers/gpu/nvgpu/include/nvgpu/io.h
@@ -40,6 +40,7 @@ struct gk20a;
 
 void nvgpu_writel(struct gk20a *g, u32 r, u32 v);
 u32 nvgpu_readl(struct gk20a *g, u32 r);
+u32 __nvgpu_readl(struct gk20a *g, u32 r);
 void nvgpu_writel_check(struct gk20a *g, u32 r, u32 v);
 void nvgpu_bar1_writel(struct gk20a *g, u32 b, u32 v);
 u32 nvgpu_bar1_readl(struct gk20a *g, u32 b);