From 5e00e3263ba68bd32337063a43aa8467b27acd1d Mon Sep 17 00:00:00 2001 From: Karol Herbst Date: Tue, 12 Jul 2016 21:36:08 +0200 Subject: [PATCH] drm/nouveau/volt: Don't require perfect fit If we calculate the voltage in the table right, we get all kinds of values, which never fit the hardware steps, so we use the closest higher value the hardware can do. v3: Simplify the implementation. v5: Initialize best_err with volt->max_uv. Signed-off-by: Karol Herbst Reviewed-by: Martin Peres Signed-off-by: Ben Skeggs --- .../gpu/drm/nouveau/nvkm/subdev/volt/base.c | 22 ++++++++++++++----- 1 file changed, 17 insertions(+), 5 deletions(-) diff --git a/drivers/gpu/drm/nouveau/nvkm/subdev/volt/base.c b/drivers/gpu/drm/nouveau/nvkm/subdev/volt/base.c index 5e07bd3aaccc..ec59d58becdc 100644 --- a/drivers/gpu/drm/nouveau/nvkm/subdev/volt/base.c +++ b/drivers/gpu/drm/nouveau/nvkm/subdev/volt/base.c @@ -51,18 +51,30 @@ static int nvkm_volt_set(struct nvkm_volt *volt, u32 uv) { struct nvkm_subdev *subdev = &volt->subdev; - int i, ret = -EINVAL; + int i, ret = -EINVAL, best_err = volt->max_uv, best = -1; if (volt->func->volt_set) return volt->func->volt_set(volt, uv); for (i = 0; i < volt->vid_nr; i++) { - if (volt->vid[i].uv == uv) { - ret = volt->func->vid_set(volt, volt->vid[i].vid); - nvkm_debug(subdev, "set %duv: %d\n", uv, ret); + int err = volt->vid[i].uv - uv; + if (err < 0 || err > best_err) + continue; + + best_err = err; + best = i; + if (best_err == 0) break; - } } + + if (best == -1) { + nvkm_error(subdev, "couldn't set %iuv\n", uv); + return ret; + } + + ret = volt->func->vid_set(volt, volt->vid[best].vid); + nvkm_debug(subdev, "set req %duv to %duv: %d\n", uv, + volt->vid[best].uv, ret); return ret; } -- 2.20.1