Re: [PATCH] Fix a panic with 1M of shared memory, no GTT entries

From: Dave Airlie
Date: Wed Jan 28 2009 - 04:13:24 EST



> 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

cc'ed Intel agp knowledge.

Dave.

>
> Signed-Off-By: Lubomir Rintel <lkundrak@xxxxx>
> ---
> drivers/char/agp/intel-agp.c | 8 +++++---
> 1 files changed, 5 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/char/agp/intel-agp.c b/drivers/char/agp/intel-agp.c
> index c771418..4373adb 100644
> --- a/drivers/char/agp/intel-agp.c
> +++ b/drivers/char/agp/intel-agp.c
> @@ -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;
> }
>
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/