drm/nouveau/clk/gf100: Read secondary bypass postdiv when required

v2: fix typo it's -> its

Signed-off-by: Roy Spliet <nouveau@spliet.org>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

diff --git a/drivers/gpu/drm/nouveau/nvkm/subdev/clk/gf100.c b/drivers/gpu/drm/nouveau/nvkm/subdev/clk/gf100.c
index 026baff..89d5543 100644 (file)
--- a/drivers/gpu/drm/nouveau/nvkm/subdev/clk/gf100.c
+++ b/drivers/gpu/drm/nouveau/nvkm/subdev/clk/gf100.c
@@ -99,7 +99,7 @@ read_div(struct gf100_clk *clk, int doff, u32 dsrc, u32 dctl)
 {
        struct nvkm_device *device = clk->base.subdev.device;
        u32 ssrc = nvkm_rd32(device, dsrc + (doff * 4));
-       u32 sctl = nvkm_rd32(device, dctl + (doff * 4));
+       u32 sclk, sctl, sdiv = 2;
 
        switch (ssrc & 0x00000003) {
        case 0:
@@ -109,13 +109,21 @@ read_div(struct gf100_clk *clk, int doff, u32 dsrc, u32 dctl)
        case 2:
                return 100000;
        case 3:
-               if (sctl & 0x80000000) {
-                       u32 sclk = read_vco(clk, dsrc + (doff * 4));
-                       u32 sdiv = (sctl & 0x0000003f) + 2;
-                       return (sclk * 2) / sdiv;
+               sclk = read_vco(clk, dsrc + (doff * 4));
+
+               /* Memclk has doff of 0 despite its alt. location */
+               if (doff <= 2) {
+                       sctl = nvkm_rd32(device, dctl + (doff * 4));
+
+                       if (sctl & 0x80000000) {
+                               if (ssrc & 0x100)
+                                       sctl >>= 8;
+
+                               sdiv = (sctl & 0x3f) + 2;
+                       }
                }
 
-               return read_vco(clk, dsrc + (doff * 4));
+               return (sclk * 2) / sdiv;
        default:
                return 0;
        }