From: Daniel Mack <daniel@caiaq.de>
To: Alan Stern <stern@rowland.harvard.edu>
Cc: Pedro Ribeiro <pedrib@gmail.com>,
Robert Hancock <hancockrwd@gmail.com>,
linux-kernel@vger.kernel.org, akpm@linux-foundation.org,
Greg KH <gregkh@suse.de>,
alsa-devel@alsa-project.org, linux-usb@vger.kernel.org
Subject: Re: USB transfer_buffer allocations on 64bit systems
Date: Fri, 9 Apr 2010 22:14:48 +0200 [thread overview]
Message-ID: <20100409201448.GL30801@buzzloop.caiaq.de> (raw)
In-Reply-To: <Pine.LNX.4.44L0.1004091529240.1852-100000@iolanthe.rowland.org>
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. :-(
FWIW, as I stated in the first message of this thread, I had very
similar bug reports for a Mac OS X driver I'm maintaining, and the
solution that fixed everything was to force memory that has a _physical_
buffer address mask of 0x00000000ffffffff. And all machines I've seen
the bug on had 4GB of RAM or less. So appearantly, without that force
option, memory beyond the 4GB range was provided.
But I can't tell whether this effect also counts for Linux, and I must
admit I lack a deep enough understanding about the kernel's memory
management in 64bit mode and about how the DMA bouncing and remapping
logic works. Does anyone have an idea about how to explain that?
Daniel
next prev parent reply other threads:[~2010-04-09 20:15 UTC|newest]
Thread overview: 138+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-04-07 9:06 USB transfer_buffer allocations on 64bit systems Daniel Mack
[not found] ` <p2g581ef6d61004070220z1153d40ez955b356e01220848@mail.gmail.com>
2010-04-07 9:26 ` USB HID gadget driver (was: Re: USB transfer_buffer allocations on 64bit systems) Daniel Mack
2010-04-07 14:59 ` USB transfer_buffer allocations on 64bit systems Alan Stern
2010-04-07 15:11 ` Daniel Mack
2010-04-07 15:31 ` Greg KH
2010-04-07 15:35 ` Daniel Mack
2010-04-07 15:51 ` Greg KH
2010-04-07 16:04 ` Alan Stern
2010-04-08 6:09 ` Oliver Neukum
2010-04-08 11:07 ` Daniel Mack
2010-04-07 15:55 ` Alan Stern
2010-04-07 16:16 ` Daniel Mack
2010-04-07 16:47 ` Alan Stern
2010-04-07 17:55 ` Takashi Iwai
2010-04-07 17:59 ` Daniel Mack
2010-04-07 18:06 ` Takashi Iwai
2010-04-07 19:13 ` Alan Stern
2010-04-07 23:59 ` Robert Hancock
2010-04-08 0:33 ` Greg KH
2010-04-09 0:01 ` Robert Hancock
2010-04-09 16:50 ` Sarah Sharp
2010-04-09 23:38 ` Robert Hancock
2010-04-10 8:34 ` [alsa-devel] " Daniel Mack
2010-04-10 17:02 ` Robert Hancock
2010-04-12 18:56 ` Sarah Sharp
2010-04-12 20:39 ` Robert Hancock
2010-04-12 20:58 ` Sarah Sharp
2010-04-12 11:17 ` [PATCH] USB: rename usb_buffer_alloc() and usb_buffer_free() Daniel Mack
2010-04-13 18:16 ` Daniel Mack
2010-04-13 19:27 ` Alan Stern
2010-04-13 20:26 ` Greg KH
2010-04-13 21:47 ` Daniel Mack
2010-04-07 17:52 ` USB transfer_buffer allocations on 64bit systems Takashi Iwai
2010-04-07 15:46 ` Alan Stern
2010-04-08 6:12 ` Oliver Neukum
2010-04-08 16:59 ` Alan Stern
2010-04-08 21:24 ` Oliver Neukum
2010-04-08 22:20 ` Alan Stern
2010-04-09 6:04 ` Oliver Neukum
2010-04-09 14:41 ` Alan Stern
2010-04-09 14:50 ` Oliver Neukum
2010-04-09 15:15 ` Alan Stern
2010-04-09 20:51 ` Oliver Neukum
2010-04-09 21:21 ` Alan Stern
2010-04-07 16:54 ` Oliver Neukum
2010-04-07 17:00 ` Daniel Mack
2010-04-07 23:55 ` Robert Hancock
2010-04-08 2:10 ` Alan Stern
2010-04-08 7:30 ` Daniel Mack
2010-04-08 16:57 ` Alan Stern
2010-04-08 17:17 ` Pedro Ribeiro
2010-04-08 18:17 ` Alan Stern
2010-04-08 23:13 ` Pedro Ribeiro
2010-04-09 16:01 ` Alan Stern
2010-04-09 18:09 ` Daniel Mack
2010-04-09 18:19 ` Pedro Ribeiro
2010-04-09 19:34 ` Alan Stern
2010-04-09 20:14 ` Daniel Mack [this message]
2010-04-09 20:25 ` [LKML] " Konrad Rzeszutek Wilk
2010-04-09 21:23 ` Alan Stern
2010-04-09 22:11 ` Robert Hancock
2010-04-12 10:48 ` Daniel Mack
2010-04-12 12:06 ` Pedro Ribeiro
2010-04-10 12:49 ` Daniel Mack
2010-04-10 13:21 ` Pedro Ribeiro
2010-04-12 8:59 ` Andi Kleen
2010-04-12 11:14 ` Daniel Mack
2010-04-12 11:53 ` Andi Kleen
2010-04-12 12:11 ` Pedro Ribeiro
2010-04-12 12:12 ` Andi Kleen
2010-04-12 12:32 ` Daniel Mack
2010-04-12 12:47 ` Andi Kleen
2010-04-12 12:54 ` Daniel Mack
2010-04-12 15:43 ` Andi Kleen
2010-04-12 16:17 ` Alan Stern
2010-04-12 16:29 ` Andi Kleen
2010-04-12 16:57 ` Alan Stern
2010-04-12 17:15 ` Daniel Mack
2010-04-12 17:22 ` Andi Kleen
2010-04-12 17:56 ` Daniel Mack
2010-04-12 17:52 ` [LKML] " Konrad Rzeszutek Wilk
2010-04-13 18:22 ` Daniel Mack
2010-04-13 23:46 ` Pedro Ribeiro
2010-04-14 10:09 ` Daniel Mack
2010-04-14 10:47 ` Pedro Ribeiro
2010-04-14 11:02 ` Pedro Ribeiro
2010-04-14 13:18 ` [LKML] " Konrad Rzeszutek Wilk
2010-04-14 14:08 ` Alan Stern
2010-04-14 16:36 ` Daniel Mack
2010-04-14 17:21 ` Pedro Ribeiro
2010-04-14 18:23 ` Alan Stern
2010-04-14 18:27 ` Pedro Ribeiro
2010-04-14 18:53 ` Alan Stern
2010-04-15 7:35 ` Daniel Mack
2010-04-14 18:15 ` Alan Stern
2010-04-14 18:36 ` David Woodhouse
2010-04-14 21:12 ` Pedro Ribeiro
2010-04-14 22:25 ` Chris Wright
2010-04-14 22:56 ` Pedro Ribeiro
2010-04-14 23:37 ` Chris Wright
2010-04-15 1:20 ` Pedro Ribeiro
2010-04-15 15:20 ` Alan Stern
2010-04-20 0:16 ` Pedro Ribeiro
2010-05-07 7:48 ` Daniel Mack
2010-05-07 9:47 ` [alsa-devel] " Clemens Ladisch
2010-05-07 10:24 ` Daniel Mack
2010-05-07 14:51 ` Alan Stern
2010-05-10 2:50 ` FUJITA Tomonori
2010-05-10 9:21 ` David Woodhouse
2010-05-10 14:58 ` Alan Stern
2010-05-11 1:06 ` FUJITA Tomonori
2010-05-11 14:00 ` Alan Stern
2010-05-11 14:22 ` FUJITA Tomonori
2010-05-11 14:24 ` Konrad Rzeszutek Wilk
2010-05-11 14:38 ` FUJITA Tomonori
2010-05-11 15:04 ` Alan Stern
2010-05-11 15:34 ` FUJITA Tomonori
2010-05-11 16:06 ` Alan Stern
2010-05-11 16:09 ` Daniel Mack
2010-05-11 16:48 ` Pedro Ribeiro
2010-05-11 17:10 ` Daniel Mack
2010-05-11 17:32 ` Pedro Ribeiro
2010-05-11 17:38 ` Daniel Mack
2010-05-12 23:50 ` Pedro Ribeiro
2010-05-13 9:36 ` Daniel Mack
2010-05-14 0:17 ` Pedro Ribeiro
2010-05-11 14:57 ` Alan Stern
2010-05-11 15:05 ` Daniel Mack
2010-05-10 14:31 ` Konrad Rzeszutek Wilk
2010-05-07 11:42 ` Oliver Neukum
2010-05-07 11:47 ` Oliver Neukum
2010-05-07 11:58 ` Daniel Mack
2010-05-07 14:45 ` Alan Stern
2010-04-14 18:38 ` Chris Wright
2010-04-14 20:29 ` Alan Stern
2010-04-14 21:01 ` Konrad Rzeszutek Wilk
2010-04-14 21:12 ` Pedro Ribeiro
2010-04-15 1:50 ` Alan Stern
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