From: rmorell@nvidia.com
To: Greg KH <gregkh@suse.de>
Cc: David Brownell <dbrownell@users.sourceforge.net>,
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>,
Olof Johansson <olof@lixom.net>,
Erik Gilling <konkers@android.com>,
Colin Cross <ccross@android.com>,
"linux-usb@vger.kernel.org" <linux-usb@vger.kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [RFC] Align tegra-ehci DMA transfers to 32B
Date: Fri, 17 Dec 2010 14:44:29 -0800 [thread overview]
Message-ID: <20101217224429.GF25105@morell.nvidia.com> (raw)
In-Reply-To: <20101217223227.GA19418@suse.de>
On Fri, Dec 17, 2010 at 02:32:27PM -0800, Greg KH wrote:
> On Fri, Dec 17, 2010 at 01:58:47PM -0800, Robert Morell wrote:
> > 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 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-written network drivers should
> > fall through this code with very little overhead, however.)
>
> We don't have many USB network drivers, why not just fix them up to
> handle this properly, then you will not need to change any core USB
> code, right?
The USB core code is used by devices other than USB adapters. We've
only seen this problem so far with usbnet devices, but I can't test
every USB device ever to make sure that they always align their DMA to
32 bytes.
Thanks,
Robert
> thanks,
>
> greg k-h
>
next prev parent reply other threads:[~2010-12-17 22:45 UTC|newest]
Thread overview: 47+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-12-17 21:58 [RFC] Align tegra-ehci DMA transfers to 32B Robert Morell
2010-12-17 21:58 ` [PATCH 1/2] USB: Add driver hooks for (un)?map_urb_for_dma Robert Morell
2010-12-17 21:58 ` [PATCH 2/2] USB: ehci: tegra: Align DMA transfers to 32 bytes Robert Morell
2010-12-17 22:35 ` Greg KH
2010-12-17 22:42 ` rmorell
2010-12-17 23:09 ` Greg KH
2010-12-17 23:17 ` Oliver Neukum
2010-12-17 23:35 ` Greg KH
2010-12-17 23:50 ` rmorell
2010-12-17 23:40 ` rmorell
2010-12-18 0:37 ` Greg KH
2010-12-18 1:29 ` rmorell
2010-12-17 22:32 ` [RFC] Align tegra-ehci DMA transfers to 32B Greg KH
2010-12-17 22:44 ` rmorell [this message]
2010-12-17 23:07 ` Greg KH
2010-12-17 23:07 ` David Brownell
2010-12-18 1:49 ` [PATCH v2] " Robert Morell
2010-12-19 21:38 ` [PATCH] " Robert Morell
2011-01-06 23:20 ` [PATCH v4] " Robert Morell
2011-01-20 21:41 ` [PATCH v5] " Robert Morell
2011-01-27 3:06 ` [PATCH v6] " Robert Morell
2011-01-27 3:06 ` [PATCH 1/3] USB: HCD: Add usb_hcd prefix to exported functions Robert Morell
2011-01-27 16:01 ` Alan Stern
2011-01-27 3:06 ` [PATCH 2/3] USB: HCD: Add driver hooks for (un)?map_urb_for_dma Robert Morell
2011-01-27 16:01 ` Alan Stern
2011-01-27 3:06 ` [PATCH 3/3] USB: ehci: tegra: Align DMA transfers to 32 bytes Robert Morell
2011-02-04 19:49 ` Greg KH
2011-02-04 20:14 ` Olof Johansson
2011-02-04 20:16 ` Greg KH
2011-02-04 20:26 ` rmorell
2011-02-04 20:35 ` Greg KH
2011-01-20 21:41 ` [PATCH 1/2] USB: HCD: Add driver hooks for (un)?map_urb_for_dma Robert Morell
2011-01-23 3:46 ` Greg KH
2011-01-24 16:32 ` Alan Stern
2011-01-20 21:41 ` [PATCH 2/2] USB: ehci: tegra: Align DMA transfers to 32 bytes Robert Morell
2011-01-24 16:36 ` Alan Stern
2011-01-24 22:53 ` rmorell
2011-01-25 2:59 ` Alan Stern
2011-01-06 23:20 ` [PATCH v4 1/2] USB: HCD: Add driver hooks for (un)?map_urb_for_dma Robert Morell
2011-01-06 23:20 ` [PATCH v4 2/2] USB: ehci: tegra: Align DMA transfers to 32 bytes Robert Morell
2010-12-19 21:38 ` [PATCH 1/2] USB: Add driver hooks for (un)?map_urb_for_dma Robert Morell
2010-12-19 21:38 ` [PATCH 2/2] USB: ehci: tegra: Align DMA transfers to 32 bytes Robert Morell
2010-12-19 21:57 ` Oliver Neukum
2010-12-18 1:49 ` [PATCH v2 1/2] USB: Add driver hooks for (un)?map_urb_for_dma Robert Morell
2010-12-18 17:51 ` Greg KH
2010-12-18 1:49 ` [PATCH v2 2/2] USB: ehci: tegra: Align DMA transfers to 32 bytes Robert Morell
2010-12-18 17:52 ` Greg KH
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