From: Stephen Warren <swarren@nvidia.com>
Date: Wed, 5 Jan 2011 21:24:12 +0000 (-0700)
Subject: ARM: tegra: Prevent requeuing in-progress DMA requests
X-Git-Tag: v2.6.39-rc1~474^2~36
X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=499ef7a5c48ea9fe8034b61de304ce9f6b753fe7;p=pandora-kernel.git

ARM: tegra: Prevent requeuing in-progress DMA requests

If a request already in the queue is passed to tegra_dma_enqueue_req,
tegra_dma_req.node->{next,prev} will end up pointing to itself instead
of at tegra_dma_channel.list, which is the way a the end-of-list
should be set up. When the DMA request completes and is list_del'd,
the list head will still point at it, yet the node's next/prev will
contain the list poison values. When the next DMA request completes,
a kernel panic will occur when those poison values are dereferenced.

This makes the DMA driver more robust in the face of buggy clients.

Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Colin Cross <ccross@android.com>
---

Reading git-diff-tree failed