drm/nouveau/volt: Parse the max voltage map entries

There are at least three "max" entries, which specify the max voltage.
Because they are actually normal voltage map entries, they can also be
affected by the temperature.

Nvidia respects those entries and if they get changed, nvidia uses the
lower voltage from all three.

We shouldn't exceed those voltages at any given time.

v2: State what those entries do in the source.
v3: Add the third max entry.
v5: Better describe the entries.

Signed-off-by: Karol Herbst <karolherbst@gmail.com>
Reviewed-by: Martin Peres <martin.peres@free.fr>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
This commit is contained in:
Karol Herbst 2016-07-12 21:36:08 +02:00 committed by Ben Skeggs
parent 17d063dbdc
commit 4a4555a7f1
4 changed files with 36 additions and 0 deletions

View file

@ -1,6 +1,9 @@
#ifndef __NVBIOS_VMAP_H__
#define __NVBIOS_VMAP_H__
struct nvbios_vmap {
u8 max0;
u8 max1;
u8 max2;
};
u16 nvbios_vmap_table(struct nvkm_bios *, u8 *ver, u8 *hdr, u8 *cnt, u8 *len);

View file

@ -15,6 +15,16 @@ struct nvkm_volt {
u32 max_uv;
u32 min_uv;
/*
* These are fully functional map entries creating a sw ceiling for
* the voltage. These all can describe different kind of curves, so
* that for any given temperature a different one can return the lowest
* value of all three.
*/
u8 max0_id;
u8 max1_id;
u8 max2_id;
};
int nvkm_volt_map_min(struct nvkm_volt *volt, u8 id);

View file

@ -61,7 +61,17 @@ nvbios_vmap_parse(struct nvkm_bios *bios, u8 *ver, u8 *hdr, u8 *cnt, u8 *len,
memset(info, 0x00, sizeof(*info));
switch (!!vmap * *ver) {
case 0x10:
info->max0 = 0xff;
info->max1 = 0xff;
info->max2 = 0xff;
break;
case 0x20:
info->max0 = nvbios_rd08(bios, vmap + 0x7);
info->max1 = nvbios_rd08(bios, vmap + 0x8);
if (*len >= 0xc)
info->max2 = nvbios_rd08(bios, vmap + 0xc);
else
info->max2 = 0xff;
break;
}
return vmap;

View file

@ -216,9 +216,22 @@ nvkm_volt_ctor(const struct nvkm_volt_func *func, struct nvkm_device *device,
/* Assuming the non-bios device should build the voltage table later */
if (bios) {
u8 ver, hdr, cnt, len;
struct nvbios_vmap vmap;
nvkm_volt_parse_bios(bios, volt);
nvkm_debug(&volt->subdev, "min: %iuv max: %iuv\n",
volt->min_uv, volt->max_uv);
if (nvbios_vmap_parse(bios, &ver, &hdr, &cnt, &len, &vmap)) {
volt->max0_id = vmap.max0;
volt->max1_id = vmap.max1;
volt->max2_id = vmap.max2;
} else {
volt->max0_id = 0xff;
volt->max1_id = 0xff;
volt->max2_id = 0xff;
}
}
if (volt->vid_nr) {