1 files changed, 8 insertions, 3 deletions

diff --git a/drivers/char/agp/generic.c b/drivers/char/agp/generic.c
index 883a36a27833..3491d6f84bc6 100644
--- a/drivers/char/agp/generic.c
+++ b/drivers/char/agp/generic.c
@@ -965,6 +965,9 @@ int agp_generic_insert_memory(struct agp_memory * mem, off_t pg_start, int type)
         if (!bridge)
                 return -EINVAL;
 
+        if (mem->page_count == 0)
+                return 0;
+
         temp = bridge->current_size;
 
         switch (bridge->driver->size_type) {
@@ -1016,8 +1019,8 @@ int agp_generic_insert_memory(struct agp_memory * mem, off_t pg_start, int type)
 
         for (i = 0, j = pg_start; i < mem->page_count; i++, j++) {
                 writel(bridge->driver->mask_memory(bridge, mem->memory[i], mem->type), bridge->gatt_table+j);
-                readl(bridge->gatt_table+j);    /* PCI Posting. */
         }
+        readl(bridge->gatt_table+j-1);  /* PCI Posting. */
 
         bridge->driver->tlb_flush(mem);
         return 0;
@@ -1034,6 +1037,9 @@ int agp_generic_remove_memory(struct agp_memory *mem, off_t pg_start, int type)
         if (!bridge)
                 return -EINVAL;
 
+        if (mem->page_count == 0)
+                return 0;
+
         if (type != 0 || mem->type != 0) {
                 /* The generic routines know nothing of memory types */
                 return -EINVAL;
@@ -1042,10 +1048,9 @@ int agp_generic_remove_memory(struct agp_memory *mem, off_t pg_start, int type)
         /* AK: bogus, should encode addresses > 4GB */
         for (i = pg_start; i < (mem->page_count + pg_start); i++) {
                 writel(bridge->scratch_page, bridge->gatt_table+i);
-                readl(bridge->gatt_table+i);    /* PCI Posting. */
         }
+        readl(bridge->gatt_table+i-1);  /* PCI Posting. */
 
-        global_cache_flush();
         bridge->driver->tlb_flush(mem);
         return 0;
 }