diff --git a/drivers/gpu/drm/nouveau/core/include/subdev/bios/init.h b/drivers/gpu/drm/nouveau/core/include/subdev/bios/init.h index e69a8bdc6e97..ca2f6bf37f46 100644 --- a/drivers/gpu/drm/nouveau/core/include/subdev/bios/init.h +++ b/drivers/gpu/drm/nouveau/core/include/subdev/bios/init.h @@ -13,6 +13,7 @@ struct nvbios_init { u32 nested; u16 repeat; u16 repend; + u32 ramcfg; }; int nvbios_exec(struct nvbios_init *); diff --git a/drivers/gpu/drm/nouveau/core/subdev/bios/init.c b/drivers/gpu/drm/nouveau/core/subdev/bios/init.c index 98f78cf318b0..2917d552689b 100644 --- a/drivers/gpu/drm/nouveau/core/subdev/bios/init.c +++ b/drivers/gpu/drm/nouveau/core/subdev/bios/init.c @@ -410,10 +410,26 @@ init_ram_restrict_group_count(struct nvbios_init *init) return 0x00; } +static u8 +init_ram_restrict_strap(struct nvbios_init *init) +{ + /* This appears to be the behaviour of the VBIOS parser, and *is* + * important to cache the NV_PEXTDEV_BOOT0 on later chipsets to + * avoid fucking up the memory controller (somehow) by reading it + * on every INIT_RAM_RESTRICT_ZM_GROUP opcode. + * + * Preserving the non-caching behaviour on earlier chipsets just + * in case *not* re-reading the strap causes similar breakage. + */ + if (!init->ramcfg || init->bios->version.major < 0x70) + init->ramcfg = init_rd32(init, 0x101000); + return (init->ramcfg & 0x00000003c) >> 2; +} + static u8 init_ram_restrict(struct nvbios_init *init) { - u32 strap = (init_rd32(init, 0x101000) & 0x0000003c) >> 2; + u8 strap = init_ram_restrict_strap(init); u16 table = init_ram_restrict_table(init); if (table) return nv_ro08(init->bios, table + strap);