Re: [LKML] Re: USB transfer_buffer allocations on 64bit systems

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



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.

--
To unsubscribe from this list: send the line "unsubscribe linux-usb" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html

[Index of Archives]     [Linux Media]     [Linux Input]     [Linux Audio Users]     [Yosemite News]     [Linux Kernel]     [Linux SCSI]     [Old Linux USB Devel Archive]

  Powered by Linux