Re: Problem: screen partially garbled in i830m (regression)

[Dave Airlie <airlied@linux.ie>]

> reply so far, that's why I'm posting to LKML this time.  Short summary:
> 874808c6dd429f7431b906a32c7f78a68e7636af broke intel_agp.ko for me, I'm
> getting a garbled screen.

Can you try the attached patch?

Dave.

From 56e5b226de1406812bbe739caad0d2a93f8c596d Mon Sep 17 00:00:00 2001
From: Dave Airlie <airlied@linux.ie>
Date: Thu, 13 Sep 2007 00:08:01 +1000
Subject: [PATCH] intel-agp: Fix i830 mask variable that changed with G33 support

The mask on i830 should be 0x70 always, later chips 0xF0 should be okay.

Signed-off-by: Dave Airlie <airlied@linux.ie>
---
 drivers/char/agp/agp.h       |    3 ++-
 drivers/char/agp/intel-agp.c |    2 +-
 2 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/char/agp/agp.h b/drivers/char/agp/agp.h
index 35ab1a9..8955e7f 100644
--- a/drivers/char/agp/agp.h
+++ b/drivers/char/agp/agp.h
@@ -176,7 +176,7 @@ struct agp_bridge_data {
 #define I830_GMCH_MEM_MASK		0x1
 #define I830_GMCH_MEM_64M		0x1
 #define I830_GMCH_MEM_128M		0
-#define I830_GMCH_GMS_MASK		0xF0
+#define I830_GMCH_GMS_MASK		0x70
 #define I830_GMCH_GMS_DISABLED		0x00
 #define I830_GMCH_GMS_LOCAL		0x10
 #define I830_GMCH_GMS_STOLEN_512	0x20
@@ -190,6 +190,7 @@ struct agp_bridge_data {
 #define INTEL_I830_ERRSTS	0x92
 
 /* Intel 855GM/852GM registers */
+#define I855_GMCH_GMS_MASK		0xF0
 #define I855_GMCH_GMS_STOLEN_0M		0x0
 #define I855_GMCH_GMS_STOLEN_1M		(0x1 << 4)
 #define I855_GMCH_GMS_STOLEN_4M		(0x2 << 4)
diff --git a/drivers/char/agp/intel-agp.c b/drivers/char/agp/intel-agp.c
index 2c9ca2c..c15f5d2 100644
--- a/drivers/char/agp/intel-agp.c
+++ b/drivers/char/agp/intel-agp.c
@@ -506,7 +506,7 @@ static void intel_i830_init_gtt_entries(void)
 			break;
 		}
 	} else {
-		switch (gmch_ctrl & I830_GMCH_GMS_MASK) {
+		switch (gmch_ctrl & I855_GMCH_GMS_MASK) {
 		case I855_GMCH_GMS_STOLEN_1M:
 			gtt_entries = MB(1) - KB(size);
 			break;
-- 
1.5.2.5