drm/nva3/clk: better pll calculation when no fractional fb div available
The core/mem/shader clocks don't support the fractional feedback divider,
causing our calculated clocks to be off by quite a lot in some cases. To
solve this we will switch to a search-based algorithm when fN is NULL.
For my NVA8 at PL3, this actually generates identical cooefficients to
the binary driver. Hopefully that's a good sign, and that does not
break VPLL calculation for someone..
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
diff --git a/drivers/gpu/drm/nouveau/nv50_crtc.c b/drivers/gpu/drm/nouveau/nv50_crtc.c
index e900a51..b522a3a 100644
--- a/drivers/gpu/drm/nouveau/nv50_crtc.c
+++ b/drivers/gpu/drm/nouveau/nv50_crtc.c
@@ -286,7 +286,7 @@
nv_wr32(dev, pll.reg + 8, reg2 | (P << 28) | (M2 << 16) | N2);
} else
if (dev_priv->chipset < NV_C0) {
- ret = nv50_calc_pll2(dev, &pll, pclk, &N1, &N2, &M1, &P);
+ ret = nva3_calc_pll(dev, &pll, pclk, &N1, &N2, &M1, &P);
if (ret <= 0)
return 0;
@@ -298,7 +298,7 @@
nv_wr32(dev, pll.reg + 4, reg1 | (P << 16) | (M1 << 8) | N1);
nv_wr32(dev, pll.reg + 8, N2);
} else {
- ret = nv50_calc_pll2(dev, &pll, pclk, &N1, &N2, &M1, &P);
+ ret = nva3_calc_pll(dev, &pll, pclk, &N1, &N2, &M1, &P);
if (ret <= 0)
return 0;