Messages in this thread | ![/](/images/icornerl.gif) | | Date | Mon, 12 Apr 2010 13:06:51 +0100 | Subject | Re: [LKML] Re: USB transfer_buffer allocations on 64bit systems | From | Pedro Ribeiro <> |
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On 12 April 2010 11:48, Daniel Mack <daniel@caiaq.de> wrote: > On Fri, Apr 09, 2010 at 04:11:52PM -0600, Robert Hancock wrote: >> On Fri, Apr 9, 2010 at 3:23 PM, Alan Stern <stern@rowland.harvard.edu> wrote: >> > On Fri, 9 Apr 2010, Konrad Rzeszutek Wilk wrote: >> > >> >> On Fri, Apr 09, 2010 at 03:34:06PM -0400, Alan Stern wrote: >> >> > On Fri, 9 Apr 2010, Pedro Ribeiro wrote: >> >> > >> >> > > > The DMA pointers do indeed look sane. I wanted to take a deeper look at >> >> > > > this and set up a 64bit system today. However, I fail to see the problem >> >> > > > here. Pedro, how much RAM does your machine have installed? >> >> > >> >> > > It has 4 GB. >> >> > >> >> > That means DMA mapping cannot be the cause of the problem. :-( >> >> >> >> That isn't entirely true. The BIOS usually allocates a 256 MB ACPI/PCI hole >> >> that is under the 4GB. >> >> >> >> So end up with 3.7 GB, then the 256MB hole, and then right above the 4GB >> >> you the the remaining memory: 4.3GB. >> > >> > How can Pedro find out what physical addresses are in use on his >> > system? >> >> If you have 4GB of RAM then almost certainly you have memory located >> at addresses over 4GB. If you look at the e820 memory map printed at >> the start of dmesg on bootup and see entries with addresses of >> 100000000 or higher reported as usable, then this is the case. > > Pedro, can you provide your dmesg output, please? I installed 5GB or RAM > to my machine now, and even with your .config, I can't see the problem. > > Daniel > >
There you go Daniel.
Pedro [unhandled content-type:application/x-gzip] | ![\](/images/icornerr.gif) |