Commit 9c1e8a4e authored Mar 10, 2009 by Lubomir Rintel Committed by Linus Torvalds Mar 10, 2009

intel-agp: fix a panic with 1M of shared memory, no GTT entries

When GTT size is equal to amount of video memory, the amount of GTT
entries is computed lower than zero, which is invalid and leads to
off-by-one error in intel_i915_configure()

Originally posted here:
http://bugzilla.kernel.org/show_bug.cgi?id=12539
http://bugzilla.redhat.com/show_bug.cgi?id=445592



Signed-off-by: Lubomir Rintel <lkundrak@v3.sk>
Cc: Lubomir Rintel <lkundrak@v3.sk>
Cc: Dave Airlie <airlied@linux.ie>
Reviewed-by: Eric Anholt <eric@anholt.net>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent 229cc58b

drivers/char/agp/intel-agp.c

+5 −3

Original line number	Diff line number	Diff line
		@@ -633,13 +633,15 @@ static void intel_i830_init_gtt_entries(void)
		break;
		}
		}
		if (gtt_entries > 0)
		if (gtt_entries > 0) {
		dev_info(&agp_bridge->dev->dev, "detected %dK %s memory\n",
		gtt_entries / KB(1), local ? "local" : "stolen");
		else
		gtt_entries /= KB(4);
		} else {
		dev_info(&agp_bridge->dev->dev,
		"no pre-allocated video memory detected\n");
		gtt_entries /= KB(4);
		gtt_entries = 0;
		}

		intel_private.gtt_entries = gtt_entries;
		}