On Fri, Jan 28, 2011 at 09:44:17PM -0500, Ted Unangst wrote:
>
> I'm a little scared of counting to 1000 here. Does i = 100 work? And
> is there a reason to write the loop backwards?
>
If you're sharing tedu's concerns, try the version of the patch
below, and report the higher number of loops you see in your console
log.
Index: i915_drv.c
===================================================================
RCS file: /cvs/OpenBSD/src/sys/dev/pci/drm/i915_drv.c,v
retrieving revision 1.101
diff -u -r1.101 i915_drv.c
--- i915_drv.c 21 Sep 2010 23:05:41 -0000 1.101
+++ i915_drv.c 31 Jan 2011 21:09:43 -0000
@@ -995,16 +995,19 @@
bus_space_write_4(dev_priv->ifp.i9xx.bst,
dev_priv->ifp.i9xx.bsh, 0, 1);
} else {
- /*
- * I8XX don't have a flush page mechanism, but do have the
- * cache. Do it the bruteforce way. we write 1024 byes into
- * the cache, then clflush them out so they'll kick the stuff
- * we care about out of the chipset cache.
- */
- if (dev_priv->ifp.i8xx.kva != NULL) {
- memset(dev_priv->ifp.i8xx.kva, 0, 1024);
- agp_flush_cache_range((vaddr_t)dev_priv->ifp.i8xx.kva,
- 1024);
+ int i;
+
+ wbinvd();
+
+#define I830_HIC 0x70
+
+ I915_WRITE(I830_HIC, (I915_READ(I830_HIC) | (1<<31)));
+ for (i = 0; i < 1000; i++) {
+ if (!(I915_READ(I830_HIC) & (1<<31))) {
+ if (i) printf("i830_HIC waited %d loops\n", i);
+ break;
+ }
+ delay(100);
}
}
}
--
Matthieu Herrb
