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authorDavid Woodhouse <dwmw2@infradead.org>2009-12-02 11:00:05 +0000
committerGreg Kroah-Hartman <gregkh@suse.de>2010-01-18 10:19:53 -0800
commit5877960869333e42ebeb733e8d9d5630ff96d350 (patch)
treeb7c79b337b7e99fb42a090264f69df3ce8cfc466
parent5deb72edb39542650c73e3fa7bf4a4a3ef14cc63 (diff)
agp/intel-agp: Clear entire GTT on startup
commit fc61901373987ad61851ed001fe971f3ee8d96a3 upstream. Some BIOSes fail to initialise the GTT, which will cause DMA faults when the IOMMU is enabled. We need to clear the whole thing to point at the scratch page, not just the part that Linux is going to use. Signed-off-by: David Woodhouse <David.Woodhouse@intel.com> [anholt: Note that this may also help with stability in the presence of driver bugs, by not drawing to memory we don't own] Signed-off-by: Eric Anholt <eric@anholt.net> Cc: Zhenyu Wang <zhenyuw@linux.intel.com> Cc: Ben Hutchings <ben@decadent.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
-rw-r--r--drivers/char/agp/intel-agp.c7
1 files changed, 6 insertions, 1 deletions
diff --git a/drivers/char/agp/intel-agp.c b/drivers/char/agp/intel-agp.c
index 3cb56a049e24..4dcfef05045a 100644
--- a/drivers/char/agp/intel-agp.c
+++ b/drivers/char/agp/intel-agp.c
@@ -178,6 +178,7 @@ static struct _intel_private {
* popup and for the GTT.
*/
int gtt_entries; /* i830+ */
+ int gtt_total_size;
union {
void __iomem *i9xx_flush_page;
void *i8xx_flush_page;
@@ -1153,7 +1154,7 @@ static int intel_i915_configure(void)
readl(intel_private.registers+I810_PGETBL_CTL); /* PCI Posting. */
if (agp_bridge->driver->needs_scratch_page) {
- for (i = intel_private.gtt_entries; i < current_size->num_entries; i++) {
+ for (i = intel_private.gtt_entries; i < intel_private.gtt_total_size; i++) {
writel(agp_bridge->scratch_page, intel_private.gtt+i);
}
readl(intel_private.gtt+i-1); /* PCI Posting. */
@@ -1308,6 +1309,8 @@ static int intel_i915_create_gatt_table(struct agp_bridge_data *bridge)
if (!intel_private.gtt)
return -ENOMEM;
+ intel_private.gtt_total_size = gtt_map_size / 4;
+
temp &= 0xfff80000;
intel_private.registers = ioremap(temp, 128 * 4096);
@@ -1395,6 +1398,8 @@ static int intel_i965_create_gatt_table(struct agp_bridge_data *bridge)
if (!intel_private.gtt)
return -ENOMEM;
+ intel_private.gtt_total_size = gtt_size / 4;
+
intel_private.registers = ioremap(temp, 128 * 4096);
if (!intel_private.registers) {
iounmap(intel_private.gtt);