agp/intel: Fix resume regression from 2d2430cf

On i915 [EeePCs] something scribles over the registers during suspend
and resume so we must save a copy of the PGETBL_CTL register programmed
by the BIOS and restore that upon resume.

Reported-by: Sitsofe Wheeler <sitsofe@yahoo.com>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>

1 files changed, 10 insertions, 4 deletions

diff --git a/drivers/char/agp/intel-gtt.c b/drivers/char/agp/intel-gtt.c
index 791582c73ff7..ebdeab26ee3c 100644
--- a/drivers/char/agp/intel-gtt.c
+++ b/drivers/char/agp/intel-gtt.c
@@ -98,6 +98,7 @@ static struct _intel_private {
         u8 __iomem *registers;
         phys_addr_t gtt_bus_addr;
         phys_addr_t gma_bus_addr;
+        phys_addr_t pte_bus_addr;
         u32 __iomem *gtt;               /* I915G */
         int num_dcache_entries;
         union {
@@ -896,11 +897,9 @@ static void intel_i830_chipset_flush(struct agp_bridge_data *bridge)
 
 static void intel_enable_gtt(void)
 {
-        u32 ptetbl_addr, gma_addr;
+        u32 gma_addr;
         u16 gmch_ctrl;
 
-        ptetbl_addr = readl(intel_private.registers+I810_PGETBL_CTL) & 0xfffff000;
-
         if (INTEL_GTT_GEN == 2)
                 pci_read_config_dword(intel_private.pcidev, I810_GMADDR,
                                       &gma_addr);
@@ -914,7 +913,8 @@ static void intel_enable_gtt(void)
         gmch_ctrl |= I830_GMCH_ENABLED;
         pci_write_config_word(intel_private.bridge_dev, I830_GMCH_CTRL, gmch_ctrl);
 
-        writel(ptetbl_addr|I810_PGETBL_ENABLED, intel_private.registers+I810_PGETBL_CTL);
+        writel(intel_private.pte_bus_addr|I810_PGETBL_ENABLED,
+               intel_private.registers+I810_PGETBL_CTL);
         readl(intel_private.registers+I810_PGETBL_CTL); /* PCI Posting. */
 }
 
@@ -930,6 +930,8 @@ static int i830_setup(void)
                 return -ENOMEM;
 
         intel_private.gtt_bus_addr = reg_addr + I810_PTE_BASE;
+        intel_private.pte_bus_addr =
+                readl(intel_private.registers+I810_PGETBL_CTL) & 0xfffff000;
 
         intel_i830_setup_flush();
 
@@ -1279,6 +1281,7 @@ static int i9xx_setup(void)
 
         if (INTEL_GTT_GEN == 3) {
                 u32 gtt_addr;
+
                 pci_read_config_dword(intel_private.pcidev,
                                       I915_PTEADDR, &gtt_addr);
                 intel_private.gtt_bus_addr = gtt_addr;
@@ -1298,6 +1301,9 @@ static int i9xx_setup(void)
                 intel_private.gtt_bus_addr = reg_addr + gtt_offset;
         }
 
+        intel_private.pte_bus_addr =
+                readl(intel_private.registers+I810_PGETBL_CTL) & 0xfffff000;
+
         intel_i9xx_setup_flush();
 
         return 0;