[AGPGART] Fix serverworks TLB flush.

Go back to what 2.4 kernels used to do here, as if this hits,
the kernel just hangs indefinitly.

Actually an improvement over 2.4 - we now break; out of the loop
instead of just printing messages on timeouts.

Signed-off-by: Dave Jones <davej@redhat.com>

1 files changed, 16 insertions, 2 deletions

diff --git a/drivers/char/agp/sworks-agp.c b/drivers/char/agp/sworks-agp.c
index a9fb12c20eb7..53968973f890 100644
--- a/drivers/char/agp/sworks-agp.c
+++ b/drivers/char/agp/sworks-agp.c
@@ -242,13 +242,27 @@ static int serverworks_fetch_size(void)
  */
 static void serverworks_tlbflush(struct agp_memory *temp)
 {
+        unsigned long timeout;
+
         writeb(1, serverworks_private.registers+SVWRKS_POSTFLUSH);
-        while (readb(serverworks_private.registers+SVWRKS_POSTFLUSH) == 1)
+        timeout = jiffies + 3*HZ;
+        while (readb(serverworks_private.registers+SVWRKS_POSTFLUSH) == 1) {
                 cpu_relax();
+                if (time_after(jiffies, timeout)) {
+                        printk(KERN_ERR PFX "TLB post flush took more than 3 seconds\n");
+                        break;
+                }
+        }
 
         writel(1, serverworks_private.registers+SVWRKS_DIRFLUSH);
-        while(readl(serverworks_private.registers+SVWRKS_DIRFLUSH) == 1)
+        timeout = jiffies + 3*HZ;
+        while (readl(serverworks_private.registers+SVWRKS_DIRFLUSH) == 1) {
                 cpu_relax();
+                if (time_after(jiffies, timeout)) {
+                        printk(KERN_ERR PFX "TLB Dir flush took more than 3 seconds\n");
+                        break;
+                }
+        }
 }
 
 static int serverworks_configure(void)