[Nouveau] [RFC PATCH 2/5] clk: drop cstates with too high voltage

[Karol Herbst]

To support boosting, vbios' seems to have fasters cstate than the actual base clock.
We should definitely drop all those with a higher voltage than the max voltage
stated in the vbios.

This fixes reclocking issues mostly on high-end kepler cards where the highest
cstates goes way beyond the max voltage supported
---
 drm/nouveau/include/nvkm/subdev/volt.h |  4 ++++
 drm/nouveau/nvkm/subdev/clk/base.c     |  6 ++++++
 drm/nouveau/nvkm/subdev/volt/base.c    | 18 ++++++++++++++++--
 3 files changed, 26 insertions(+), 2 deletions(-)

diff --git a/drm/nouveau/include/nvkm/subdev/volt.h b/drm/nouveau/include/nvkm/subdev/volt.h
index b458d04..32c1a22 100644
--- a/drm/nouveau/include/nvkm/subdev/volt.h
+++ b/drm/nouveau/include/nvkm/subdev/volt.h
@@ -12,8 +12,12 @@ struct nvkm_volt {
 		u32 uv;
 		u8 vid;
 	} vid[256];
+
+	u32 max_voltage;
+	u32 min_voltage;
 };
 
+int nvkm_volt_map(struct nvkm_volt *volt, u8 id);
 int nvkm_volt_get(struct nvkm_volt *);
 int nvkm_volt_set_id(struct nvkm_volt *, u8 id, int condition);
 
diff --git a/drm/nouveau/nvkm/subdev/clk/base.c b/drm/nouveau/nvkm/subdev/clk/base.c
index dc8682c..d731bc3 100644
--- a/drm/nouveau/nvkm/subdev/clk/base.c
+++ b/drm/nouveau/nvkm/subdev/clk/base.c
@@ -138,16 +138,22 @@ static int
 nvkm_cstate_new(struct nvkm_clk *clk, int idx, struct nvkm_pstate *pstate)
 {
 	struct nvkm_bios *bios = clk->subdev.device->bios;
+	struct nvkm_volt *volt = clk->subdev.device->volt;
 	const struct nvkm_domain *domain = clk->domains;
 	struct nvkm_cstate *cstate = NULL;
 	struct nvbios_cstepX cstepX;
 	u8  ver, hdr;
 	u16 data;
+	int voltage;
 
 	data = nvbios_cstepXp(bios, idx, &ver, &hdr, &cstepX);
 	if (!data)
 		return -ENOENT;
 
+	voltage = nvkm_volt_map(volt, cstepX.voltage);
+	if (volt && (voltage > volt->max_voltage || voltage < volt->min_voltage))
+		return -EINVAL;
+
 	cstate = kzalloc(sizeof(*cstate), GFP_KERNEL);
 	if (!cstate)
 		return -ENOMEM;
diff --git a/drm/nouveau/nvkm/subdev/volt/base.c b/drm/nouveau/nvkm/subdev/volt/base.c
index 50b5649..7104168 100644
--- a/drm/nouveau/nvkm/subdev/volt/base.c
+++ b/drm/nouveau/nvkm/subdev/volt/base.c
@@ -65,7 +65,7 @@ nvkm_volt_set(struct nvkm_volt *volt, u32 uv)
 	return ret;
 }
 
-static int
+int
 nvkm_volt_map(struct nvkm_volt *volt, u8 id)
 {
 	struct nvkm_bios *bios = volt->subdev.device->bios;
@@ -120,6 +120,9 @@ nvkm_volt_parse_bios(struct nvkm_bios *bios, struct nvkm_volt *volt)
 
 	data = nvbios_volt_parse(bios, &ver, &hdr, &cnt, &len, &info);
 	if (data && info.vidmask && info.base && info.step) {
+		volt->min_voltage = info.min;
+		volt->max_voltage = info.max;
+
 		for (i = 0; i < info.vidmask + 1; i++) {
 			if (info.base >= info.min &&
 				info.base <= info.max) {
@@ -138,9 +141,18 @@ nvkm_volt_parse_bios(struct nvkm_bios *bios, struct nvkm_volt *volt)
 				volt->vid[volt->vid_nr].uv = ivid.voltage;
 				volt->vid[volt->vid_nr].vid = ivid.vid;
 				volt->vid_nr++;
+
+				if (volt->min_voltage == 0)
+					volt->min_voltage = ivid.voltage;
+				else
+					volt->min_voltage = min(volt->min_voltage, ivid.voltage);
+				volt->max_voltage = max(volt->max_voltage, ivid.voltage);
 			}
 		}
 		volt->vid_mask = info.vidmask;
+	} else if (data && info.type == NVBIOS_VOLT_PWM) {
+		volt->min_voltage = info.base;
+		volt->max_voltage = info.base + info.pwm_range;
 	}
 }
 
@@ -181,8 +193,10 @@ nvkm_volt_ctor(const struct nvkm_volt_func *func, struct nvkm_device *device,
 	volt->func = func;
 
 	/* Assuming the non-bios device should build the voltage table later */
-	if (bios)
+	if (bios) {
 		nvkm_volt_parse_bios(bios, volt);
+		nvkm_debug(&volt->subdev, "min: %iuv max: %iuv\n", volt->min_voltage, volt->max_voltage);
+	}
 
 	if (volt->vid_nr) {
 		for (i = 0; i < volt->vid_nr; i++) {
-- 
2.6.3