From ef5b05cb60c634a7ff24b4442c299afb5c60381b Mon Sep 17 00:00:00 2001
From: Ben Skeggs <bskeggs@redhat.com>
Date: Thu, 20 Dec 2012 07:48:51 +1000
Subject: [PATCH] --- yaml --- r: 348063 b: refs/heads/master c:
 5ddf4d4a543dd3303b20d7e9a4b3549589c5f095 h: refs/heads/master i:   348061:
 f353019e957daa67a1b0f789e2fa03ed64ab7670   348059:
 d9ca91fcd5ad5e8fae57313465173c6de9d3b8dd   348055:
 c67a3b147d62ccd4d6001d3b0dcfdf6ef98b32a5   348047:
 0b90eda01c90c9dcbcfab7bc599fec6a94aa0d12   348031:
 80cbe9e65d5163cdd82c1aced3f7e0a3be0eda27 v: v3

---
 [refs]                                         |  2 +-
 .../nouveau/core/include/subdev/bios/init.h    |  1 +
 .../gpu/drm/nouveau/core/subdev/bios/init.c    | 18 +++++++++++++++++-
 3 files changed, 19 insertions(+), 2 deletions(-)

diff --git a/[refs] b/[refs]
index 1218f9fecf90..b7c2f68fee89 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 3d8ec277394ee0cf9fdd5a411017c3b4f1b0aff2
+refs/heads/master: 5ddf4d4a543dd3303b20d7e9a4b3549589c5f095
diff --git a/trunk/drivers/gpu/drm/nouveau/core/include/subdev/bios/init.h b/trunk/drivers/gpu/drm/nouveau/core/include/subdev/bios/init.h
index e69a8bdc6e97..ca2f6bf37f46 100644
--- a/trunk/drivers/gpu/drm/nouveau/core/include/subdev/bios/init.h
+++ b/trunk/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/trunk/drivers/gpu/drm/nouveau/core/subdev/bios/init.c b/trunk/drivers/gpu/drm/nouveau/core/subdev/bios/init.c
index 98f78cf318b0..2917d552689b 100644
--- a/trunk/drivers/gpu/drm/nouveau/core/subdev/bios/init.c
+++ b/trunk/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);