From: Robert Morell <rmorell@nvidia.com>
To: David Brownell <dbrownell@users.sourceforge.net>,
        Greg Kroah-Hartman <gregkh@suse.de>, Benoit Goby <benoit@android.com>,
        Alan Stern <stern@rowland.harvard.edu>,
        Sarah Sharp <sarah.a.sharp@linux.intel.com>,
        Matthew Wilcox <willy@linux.intel.com>,
        Ming Lei <tom.leiming@gmail.com>, Jacob Pan <jacob.jun.pan@intel.com>
Cc: Olof Johansson <olof@lixom.net>, Erik Gilling <konkers@android.com>,
        Colin Cross <ccross@android.com>, linux-usb@vger.kernel.org,
        linux-kernel@vger.kernel.org, linux-tegra@vger.kernel.org
Subject: [PATCH v2] Align tegra-ehci DMA transfers to 32B
Date: Fri, 17 Dec 2010 17:49:29 -0800
Message-Id: <1292636971-17701-1-git-send-email-rmorell@nvidia.com>
In-Reply-To: <1292623129-26361-1-git-send-email-rmorell@nvidia.com>
References: <1292623129-26361-1-git-send-email-rmorell@nvidia.com>
Sender: linux-kernel-owner@vger.kernel.org
Content-Length: 984
Lines: 19

This small set of patches fixes an issue where DMA from the tegra EHCI
controller could be corrupted.  It was most commonly seen with USB network
adapters, though in theory it could happen with any USB traffic.

Note: An attempt was made to fix this specifically for network devices with
commit 367c3aab, which set NET_IP_ALIGN to 0 and NET_SKB_PAD to 32.
Unfortunately, not all network drivers honor them (presumably since these are
intended as optimizations rather than hard rules).  This does mean that
properly behaved network drivers should fall through this code with very little
overhead, however.

Version 2 of this patchset gets rid of the HCD placeholder in the flags and
instead simply reserves the flag globally for this use.

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/