>From e025bfb96059be648074a02f60dff92fb658cb9a Mon Sep 17 00:00:00 2001
From: Tim Gardner <tim.gardner@canonical.com>
Date: Fri, 9 Jul 2010 11:14:41 -0600
Subject: [PATCH] i915: Use the correct mask to detect i830 aperture size.
BugLink: https://bugs.launchpad.net/bugs/597075
commit f1befe71fa7a79ab733011b045639d8d809924ad introduced a regression when
detecting aperture size of some i915 adapters, e.g., those on the
Intel Q35 chipset.
The original report: https://bugzilla.kernel.org/show_bug.cgi?id=15733
The regression report: https://bugzilla.kernel.org/show_bug.cgi?id=16294
According to the specification found at http://intellinuxgraphics.org/VOL_1_graphics_core.pdf,
the PCI config space register I830_GMCH_CTRL is a mirror of GMCH Graphics Control. The correct
macro for isolating the aperture size bits is therefore I830_GMCH_GMS_MASK along with the
attendant changes to the case statement.
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
Tested-by: Kees Cook <kees.cook@canonical.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Eric Anholt <eric@anholt.net>
Cc: Jesse Barnes <jbarnes@virtuousgeek.org>
---
drivers/char/agp/intel-gtt.c | 13 ++++++++-----
1 files changed, 8 insertions(+), 5 deletions(-)
diff --git a/drivers/char/agp/intel-gtt.c b/drivers/char/agp/intel-gtt.c
index 9344216..a754715 100644
--- a/drivers/char/agp/intel-gtt.c
+++ b/drivers/char/agp/intel-gtt.c
@@ -1216,17 +1216,20 @@ static int intel_i915_get_gtt_size(void)
/* 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:
+ switch (gmch_ctrl & I830_GMCH_GMS_MASK) {
+ case I830_GMCH_GMS_STOLEN_512:
+ size = 512;
+ break;
+ case I830_GMCH_GMS_STOLEN_1024:
size = 1024;
break;
- case G33_PGETBL_SIZE_2M:
- size = 2048;
+ case I830_GMCH_GMS_STOLEN_8192:
+ size = 8*1024;
break;
default:
dev_info(&agp_bridge->dev->dev,
"unknown page table size 0x%x, assuming 512KB\n",
- (gmch_ctrl & G33_PGETBL_SIZE_MASK));
+ (gmch_ctrl & I830_GMCH_GMS_MASK));
size = 512;
}
} else {
--
1.7.0.4