Re: [PATCH] atl1: disable 64bit DMA

From: Luca
Date: Tue Jun 26 2007 - 17:12:55 EST


On 6/26/07, Jeff Garzik <jgarzik@xxxxxxxxx> wrote:
Jay Cliburn wrote:
> On Mon, 25 Jun 2007 17:57:20 -0400
> Chris Snook <csnook@xxxxxxxxxx> wrote:
>
>> Jay L. T. Cornwall wrote:
>>> Chris Snook wrote:
>>>
>>>> What boards have we seen this on? It's quite possible this is:
>>> I can reproduce on an Asus P5K with a Core 2 Duo E6600.
>>>
>>> lspci identifies the controller as:
>>> 02:00.0 Ethernet controller: Attansic Technology Corp. L1 Gigabit
>>> Ethernet Adapter (rev b0)
>>>
>>> dmesg notes the PCI-DMA mapping implementation:
>>> PCI-DMA: Using software bounce buffering for IO (SWIOTLB)
>>>
>> I had a hunch this was on Intel. I'd rather just disable this when
>> swiotlb is in use, unless we get more complaints. It's probably
>> ultimately a BIOS quirk anyway.
>
> So far we have reports from both camps:
>
> Asus M2N8-VMX (AM2): 1 report of lockup
> http://sourceforge.net/mailarchive/forum.php?thread_name=46780384.063603.26165%40m12-15.163.com&forum_name=atl1-devel
>
> Asus P5K (LGA775): 2 reports of lockups
> http://sourceforge.net/mailarchive/forum.php?thread_name=467E7E34.4010603%40gmail.com&forum_name=atl1-devel
> http://lkml.org/lkml/2007/6/25/107
>
> The common denominator in these reports is 4GB RAM.

Although its possible this device doesn't really support 64-bit, it's
more likely that this is a platform problem of some sort, or a driver
bug of some sort. In the driver, maybe it has a problem when you
-cross- a 4GB boundary, which is not uncommon.

I don't follow you :| What kind "common" mistakes should we check for
in the driver?

Luca
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