[PATCH] UBUNTU: SAUCE: i915: ubreak G33 GTT size calculation

[Kees Cook]

Upstream fixed https://bugzilla.kernel.org/show_bug.cgi?id=15733
by correctly calculating the GTT size using aperture size
on non-G33 hardware.  In the process, the G33 case was
also changed, which lead to the regression documented in
https://bugzilla.kernel.org/show_bug.cgi?id=16294

This patch reverts the G33 logic without re-breaking the non-G33 logic.

BugLink: https://bugs.launchpad.net/bugs/597075

Signed-off-by: Kees Cook <kees.cook at canonical.com>
---
v2:
 - drop the entire auto-detect code for G33 since it is not correct

---
 drivers/char/agp/intel-gtt.c |   18 +-----------------
 1 files changed, 1 insertions(+), 17 deletions(-)

diff --git a/drivers/char/agp/intel-gtt.c b/drivers/char/agp/intel-gtt.c
index 9344216..01b24b8 100644
--- a/drivers/char/agp/intel-gtt.c
+++ b/drivers/char/agp/intel-gtt.c
@@ -1212,23 +1212,7 @@ static int intel_i915_get_gtt_size(void)
 	int size;
 
 	if (IS_G33) {
-		u16 gmch_ctrl;
-
-		/* G33's GTT size defined in gmch_ctrl */
-		pci_read_config_word(agp_bridge->dev, I830_GMCH_CTRL, &gmch_ctrl);
-		switch (gmch_ctrl & G33_PGETBL_SIZE_MASK) {
-		case G33_PGETBL_SIZE_1M:
-			size = 1024;
-			break;
-		case G33_PGETBL_SIZE_2M:
-			size = 2048;
-			break;
-		default:
-			dev_info(&agp_bridge->dev->dev,
-				 "unknown page table size 0x%x, assuming 512KB\n",
-				(gmch_ctrl & G33_PGETBL_SIZE_MASK));
-			size = 512;
-		}
+		size = 1024;
 	} else {
 		/* On previous hardware, the GTT size was just what was
 		 * required to map the aperture.
-- 
1.7.1


-- 
Kees Cook
Ubuntu Security Team