gpu: nvgpu: Check reference clock before use

We use GPU reference clock as a divider. Check before division that
reference clock is not zero.

Change-Id: Ie453a78b422b2e740daeb7c12ce5b06faa52ba76
Signed-off-by: Terje Bergstrom <tbergstrom@nvidia.com>
Reviewed-on: http://git-master/r/1275743
GVS: Gerrit_Virtual_Submit
Reviewed-by: Thomas Fleury <tfleury@nvidia.com>

2 files changed, 10 insertions, 0 deletions

diff --git a/drivers/gpu/nvgpu/gk20a/clk_gk20a.c b/drivers/gpu/nvgpu/gk20a/clk_gk20a.c
index 2c4f1bf4..34f3f886 100644
--- a/drivers/gpu/nvgpu/gk20a/clk_gk20a.c
+++ b/drivers/gpu/nvgpu/gk20a/clk_gk20a.c
@@ -439,6 +439,11 @@ static int gk20a_init_clk_setup_sw(struct gk20a *g)
 
         clk->gpc_pll.id = GK20A_GPC_PLL;
         clk->gpc_pll.clk_in = ref_rate / KHZ;
+        if (clk->gpc_pll.clk_in == 0) {
+                gk20a_err(dev_from_gk20a(g),
+                        "GPCPLL reference clock is zero");
+                return -EINVAL;
+        }
 
         /* Decide initial frequency */
         if (!initialized) {
diff --git a/drivers/gpu/nvgpu/gm20b/clk_gm20b.c b/drivers/gpu/nvgpu/gm20b/clk_gm20b.c
index 906e805a..3fa5c1d3 100644
--- a/drivers/gpu/nvgpu/gm20b/clk_gm20b.c
+++ b/drivers/gpu/nvgpu/gm20b/clk_gm20b.c
@@ -1158,6 +1158,11 @@ static int gm20b_init_gpc_pll(struct gk20a *g)
 
         clk->gpc_pll.id = GK20A_GPC_PLL;
         clk->gpc_pll.clk_in = clk_get_rate(ref) / KHZ;
+        if (clk->gpc_pll.clk_in == 0) {
+                gk20a_err(dev_from_gk20a(g),
+                        "GPCPLL reference clock is zero");
+                return -EINVAL;
+        }
 
         gm20b_calc_dvfs_safe_max_freq(c);
         clk->gpc_pll.PL = (dvfs_safe_max_freq == 0) ? 0 :