nvgpu: fix get_maxrate when no dvfs

In nvgpu_linux_get_maxrate, if tegra_dvfs_get_maxrate
returns 0 (a sign that there is no dvfs support), call
nvgpu_clk_arb_get_arbiter_clk_range to get the max
gpu frequency.

Bug 200543218

Change-Id: I4f9bc0acaef98cd9dfa22f709656f4bb7e9fd349
Signed-off-by: Peter Daifuku <pdaifuku@nvidia.com>
Reviewed-on: https://git-master.nvidia.com/r/2215161
GVS: Gerrit_Virtual_Submit
Reviewed-by: Alex Waterman <alexw@nvidia.com>
Reviewed-by: Satish Arora <satisha@nvidia.com>
Reviewed-by: mobile promotions <svcmobile_promotions@nvidia.com>
Tested-by: mobile promotions <svcmobile_promotions@nvidia.com>

1 files changed, 10 insertions, 0 deletions

diff --git a/drivers/gpu/nvgpu/os/linux/clk.c b/drivers/gpu/nvgpu/os/linux/clk.c
index 471f2aef..e9796eaf 100644
--- a/drivers/gpu/nvgpu/os/linux/clk.c
+++ b/drivers/gpu/nvgpu/os/linux/clk.c
@@ -122,10 +122,20 @@ static int nvgpu_linux_predict_mv_at_hz_cur_tfloor(struct clk_gk20a *clk,
 static unsigned long nvgpu_linux_get_maxrate(struct gk20a *g, u32 api_domain)
 {
         int ret;
+        u16 min_mhz, max_mhz;
 
         switch (api_domain) {
         case CTRL_CLK_DOMAIN_GPCCLK:
                 ret = tegra_dvfs_get_maxrate(g->clk.tegra_clk_parent);
+                /* If dvfs not supported */
+                if (ret == 0) {
+                        int err = nvgpu_clk_arb_get_arbiter_clk_range(g,
+                                        NVGPU_CLK_DOMAIN_GPCCLK,
+                                        &min_mhz, &max_mhz);
+                        if (err == 0) {
+                                ret = max_mhz * 1000000L;
+                        }
+                }
                 break;
         default:
                 nvgpu_err(g, "unknown clock: %u", api_domain);