From: benh@kernel.crashing.org (Benjamin Herrenschmidt)
To: linux-arm-kernel@lists.infradead.org
Subject: USB mass storage and ARM cache coherency
Date: Wed, 17 Feb 2010 20:40:09 +1100 [thread overview]
Message-ID: <1266399609.16346.271.camel@pasglop> (raw)
In-Reply-To: <201002171015.52875.oliver@neukum.org>
On Wed, 2010-02-17 at 10:15 +0100, Oliver Neukum wrote:
> We should have changed the subject line.
>
> There's a second problem. It turns out that on ARM
> mapping for DMA must not be done if PIO will be used. Some HCDs
> use PIO for some transfers but DMA for others. The generic layer
> must learn about this.
Ah, that makes a lot of sense and the same problem would happen on
any non-DMA coherent architecture, including some embedded ppc's.
I can see why the dma unmap would invalidate the dcache and blow
away the PIO.
What bugs me here is that the dma_map_* operation should always
be done at the lowest level, ie, the actual HCD driver, and thus
it should be up to the HCD to decide whether to dma_map or not
depending on whether it's going to do DMA or not. I haven't
scrutinized USB lately but if that isn't the case and the dma_map_*
operations are done behind your back by the USB core then that needs to
be changed in a way or another, or hooked at least.
Cheers,
Ben.
WARNING: multiple messages have this Message-ID (diff)
From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To: Oliver Neukum <oliver@neukum.org>
Cc: "Shilimkar, Santosh" <santosh.shilimkar@ti.com>,
Matthew Dharm <mdharm-kernel@one-eyed-alien.net>,
Russell King - ARM Linux <linux@arm.linux.org.uk>,
Ming Lei <tom.leiming@gmail.com>,
"Mankad, Maulik Ojas" <x0082077@ti.com>,
Sergei Shtylyov <sshtylyov@ru.mvista.com>,
Catalin Marinas <catalin.marinas@arm.com>,
Sebastian Siewior <bigeasy@linutronix.de>,
"linux-usb@vger.kernel.org" <linux-usb@vger.kernel.org>,
linux-kernel <linux-kernel@vger.kernel.org>,
Pavel Machek <pavel@ucw.cz>, Greg KH <greg@kroah.com>,
linux-arm-kernel <linux-arm-kernel@lists.infradead.org>
Subject: Re: USB mass storage and ARM cache coherency
Date: Wed, 17 Feb 2010 20:40:09 +1100 [thread overview]
Message-ID: <1266399609.16346.271.camel@pasglop> (raw)
In-Reply-To: <201002171015.52875.oliver@neukum.org>
On Wed, 2010-02-17 at 10:15 +0100, Oliver Neukum wrote:
> We should have changed the subject line.
>
> There's a second problem. It turns out that on ARM
> mapping for DMA must not be done if PIO will be used. Some HCDs
> use PIO for some transfers but DMA for others. The generic layer
> must learn about this.
Ah, that makes a lot of sense and the same problem would happen on
any non-DMA coherent architecture, including some embedded ppc's.
I can see why the dma unmap would invalidate the dcache and blow
away the PIO.
What bugs me here is that the dma_map_* operation should always
be done at the lowest level, ie, the actual HCD driver, and thus
it should be up to the HCD to decide whether to dma_map or not
depending on whether it's going to do DMA or not. I haven't
scrutinized USB lately but if that isn't the case and the dma_map_*
operations are done behind your back by the USB core then that needs to
be changed in a way or another, or hooked at least.
Cheers,
Ben.
next prev parent reply other threads:[~2010-02-17 9:40 UTC|newest]
Thread overview: 352+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-01-29 14:34 USB mass storage and ARM cache coherency Catalin Marinas
2010-01-29 16:10 ` Oliver Neukum
2010-01-29 16:23 ` Ming Lei
2010-01-29 16:34 ` Catalin Marinas
2010-01-29 16:41 ` Oliver Neukum
2010-01-29 17:14 ` Catalin Marinas
2010-01-29 17:51 ` Sergei Shtylyov
2010-01-29 18:54 ` Matthew Dharm
2010-01-29 19:35 ` Greg KH
2010-02-01 13:49 ` Catalin Marinas
2010-02-01 17:29 ` Catalin Marinas
2010-02-01 20:14 ` Alan Stern
2010-02-02 4:24 ` Paul Mundt
2010-02-02 9:58 ` Catalin Marinas
2010-02-01 22:30 ` Andreas Mohr
2010-02-02 6:58 ` Oliver Neukum
2010-02-02 9:31 ` Florian Fainelli
2010-02-02 6:39 ` Paul Mundt
2010-02-02 11:05 ` Catalin Marinas
2010-02-02 11:15 ` Paul Mundt
2010-02-02 9:11 ` Sebastian Andrzej Siewior
2010-02-02 11:09 ` Catalin Marinas
2010-02-02 11:48 ` Oliver Neukum
2010-02-02 12:01 ` Catalin Marinas
2010-02-02 12:07 ` Oliver Neukum
2010-02-02 12:11 ` Andreas Mohr
2010-02-02 14:42 ` Clemens Ladisch
2010-02-02 14:52 ` Oliver Neukum
2010-02-02 15:10 ` Andreas Mohr
2010-02-02 15:34 ` Catalin Marinas
2010-02-02 20:38 ` Andreas Mohr
2010-02-02 12:39 ` Catalin Marinas
2010-02-02 13:08 ` Oliver Neukum
2010-02-02 14:34 ` Catalin Marinas
2010-02-02 17:11 ` Alan Stern
2010-02-02 17:20 ` Catalin Marinas
2010-02-02 21:52 ` Andreas Mohr
2010-02-03 15:15 ` Alan Stern
2010-02-08 6:55 ` Pavel Machek
2010-02-02 13:36 ` Ming Lei
2010-02-02 14:35 ` Catalin Marinas
2010-02-08 6:55 ` Pavel Machek
2010-02-08 6:55 ` Pavel Machek
2010-02-08 7:33 ` Andreas Mohr
2010-02-08 7:33 ` Andreas Mohr
2010-02-08 10:19 ` Catalin Marinas
2010-02-08 10:19 ` Catalin Marinas
2010-02-08 9:51 ` Catalin Marinas
2010-02-08 9:51 ` Catalin Marinas
2010-02-08 10:03 ` Andy Green
2010-02-08 10:03 ` Andy Green
2010-02-17 9:50 ` Sascha Hauer
2010-02-17 9:50 ` Sascha Hauer
2010-02-17 9:57 ` Andy Green
2010-02-17 9:57 ` Andy Green
2010-02-08 10:52 ` Pavel Machek
2010-02-08 10:52 ` Pavel Machek
2010-02-08 11:28 ` Catalin Marinas
2010-02-08 11:28 ` Catalin Marinas
2010-02-16 7:57 ` Shilimkar, Santosh
2010-02-16 7:57 ` Shilimkar, Santosh
2010-02-16 8:22 ` Oliver Neukum
2010-02-16 8:22 ` Oliver Neukum
2010-02-16 8:55 ` Shilimkar, Santosh
2010-02-16 8:55 ` Shilimkar, Santosh
2010-02-16 9:07 ` Oliver Neukum
2010-02-16 9:07 ` Oliver Neukum
2010-02-16 9:39 ` Russell King - ARM Linux
2010-02-16 9:39 ` Russell King - ARM Linux
2010-02-16 13:32 ` Oliver Neukum
2010-02-16 13:32 ` Oliver Neukum
2010-02-16 13:40 ` Shilimkar, Santosh
2010-02-16 13:40 ` Shilimkar, Santosh
2010-02-16 13:46 ` Oliver Neukum
2010-02-16 13:46 ` Oliver Neukum
2010-02-16 14:12 ` Shilimkar, Santosh
2010-02-16 14:12 ` Shilimkar, Santosh
2010-02-16 14:22 ` Oliver Neukum
2010-02-16 14:22 ` Oliver Neukum
2010-02-16 14:45 ` Shilimkar, Santosh
2010-02-16 14:45 ` Shilimkar, Santosh
2010-02-16 15:44 ` Alan Stern
2010-02-16 15:44 ` Alan Stern
2010-02-17 8:55 ` Shilimkar, Santosh
2010-02-17 8:55 ` Shilimkar, Santosh
2010-02-17 9:10 ` Oliver Neukum
2010-02-17 9:10 ` Oliver Neukum
2010-02-17 9:17 ` Shilimkar, Santosh
2010-02-17 9:17 ` Shilimkar, Santosh
2010-02-17 17:02 ` Alan Stern
2010-02-17 17:02 ` Alan Stern
2010-02-17 20:26 ` Russell King - ARM Linux
2010-02-17 20:26 ` Russell King - ARM Linux
2010-02-17 20:30 ` Gadiyar, Anand
2010-02-17 20:30 ` Gadiyar, Anand
2010-02-18 6:56 ` Oliver Neukum
2010-02-18 6:56 ` Oliver Neukum
2010-02-18 7:14 ` Gadiyar, Anand
2010-02-18 7:14 ` Gadiyar, Anand
2010-02-17 12:29 ` Jamie Lokier
2010-02-17 12:29 ` Jamie Lokier
2010-02-17 3:21 ` Ming Lei
2010-02-17 3:21 ` Ming Lei
2010-02-17 9:05 ` Benjamin Herrenschmidt
2010-02-17 9:05 ` Benjamin Herrenschmidt
2010-02-17 9:15 ` Oliver Neukum
2010-02-17 9:15 ` Oliver Neukum
2010-02-17 9:40 ` Benjamin Herrenschmidt [this message]
2010-02-17 9:40 ` Benjamin Herrenschmidt
2010-02-17 10:09 ` Oliver Neukum
2010-02-17 10:09 ` Oliver Neukum
2010-02-17 10:18 ` Benjamin Herrenschmidt
2010-02-17 10:18 ` Benjamin Herrenschmidt
2010-02-17 10:23 ` Oliver Neukum
2010-02-17 10:23 ` Oliver Neukum
2010-02-17 12:15 ` Benjamin Herrenschmidt
2010-02-17 12:15 ` Benjamin Herrenschmidt
2010-02-17 9:55 ` Russell King - ARM Linux
2010-02-17 9:55 ` Russell King - ARM Linux
2010-02-17 10:05 ` Benjamin Herrenschmidt
2010-02-17 10:05 ` Benjamin Herrenschmidt
2010-02-17 15:27 ` Catalin Marinas
2010-02-17 15:27 ` Catalin Marinas
2010-02-17 20:37 ` Benjamin Herrenschmidt
2010-02-17 20:37 ` Benjamin Herrenschmidt
2010-02-17 20:44 ` Russell King - ARM Linux
2010-02-17 20:44 ` Russell King - ARM Linux
2010-02-17 22:31 ` Benjamin Herrenschmidt
2010-02-17 22:31 ` Benjamin Herrenschmidt
2010-02-19 17:15 ` Catalin Marinas
2010-02-19 17:15 ` Catalin Marinas
2010-02-19 17:36 ` Catalin Marinas
2010-02-19 17:36 ` Catalin Marinas
2010-02-19 20:53 ` Oliver Neukum
2010-02-19 20:53 ` Oliver Neukum
2010-02-24 2:48 ` Benjamin Herrenschmidt
2010-02-24 2:48 ` Benjamin Herrenschmidt
2010-02-24 7:16 ` Oliver Neukum
2010-02-24 7:16 ` Oliver Neukum
2010-02-24 21:12 ` Benjamin Herrenschmidt
2010-02-24 21:12 ` Benjamin Herrenschmidt
2010-02-25 3:48 ` Oliver Neukum
2010-02-25 3:48 ` Oliver Neukum
2010-02-26 0:22 ` Benjamin Herrenschmidt
2010-02-26 0:22 ` Benjamin Herrenschmidt
2010-02-25 12:36 ` James Bottomley
2010-02-25 12:36 ` James Bottomley
2010-02-24 2:47 ` Benjamin Herrenschmidt
2010-02-24 2:47 ` Benjamin Herrenschmidt
2010-02-24 16:19 ` Alan Stern
2010-02-24 16:19 ` Alan Stern
2010-02-24 21:13 ` Benjamin Herrenschmidt
2010-02-24 21:13 ` Benjamin Herrenschmidt
2010-02-24 21:50 ` Alan Stern
2010-02-24 21:50 ` Alan Stern
2010-02-25 20:52 ` Benjamin Herrenschmidt
2010-02-25 20:52 ` Benjamin Herrenschmidt
2010-02-26 16:00 ` Catalin Marinas
2010-02-26 16:00 ` Catalin Marinas
2010-02-26 21:36 ` Benjamin Herrenschmidt
2010-02-26 21:36 ` Benjamin Herrenschmidt
2010-02-26 16:25 ` Catalin Marinas
2010-02-26 16:25 ` Catalin Marinas
2010-02-26 16:52 ` Alan Stern
2010-02-26 16:52 ` Alan Stern
2010-02-26 21:51 ` Benjamin Herrenschmidt
2010-02-26 21:51 ` Benjamin Herrenschmidt
2010-02-26 21:00 ` Russell King - ARM Linux
2010-02-26 21:00 ` Russell King - ARM Linux
2010-02-28 0:14 ` Benjamin Herrenschmidt
2010-02-28 0:14 ` Benjamin Herrenschmidt
2010-02-28 5:01 ` James Bottomley
2010-02-28 5:01 ` James Bottomley
2010-03-01 10:39 ` Catalin Marinas
2010-03-01 10:39 ` Catalin Marinas
2010-03-01 11:06 ` Russell King - ARM Linux
2010-03-01 11:06 ` Russell King - ARM Linux
2010-03-02 12:11 ` FUJITA Tomonori
2010-03-02 12:11 ` FUJITA Tomonori
2010-03-02 17:05 ` Catalin Marinas
2010-03-02 17:05 ` Catalin Marinas
2010-03-02 17:47 ` Catalin Marinas
2010-03-02 17:47 ` Catalin Marinas
2010-03-02 23:33 ` Benjamin Herrenschmidt
2010-03-02 23:33 ` Benjamin Herrenschmidt
2010-03-03 10:21 ` Catalin Marinas
2010-03-03 10:21 ` Catalin Marinas
2010-03-02 23:29 ` Benjamin Herrenschmidt
2010-03-02 23:29 ` Benjamin Herrenschmidt
2010-03-03 3:47 ` FUJITA Tomonori
2010-03-03 3:47 ` FUJITA Tomonori
2010-03-03 5:10 ` Benjamin Herrenschmidt
2010-03-03 5:10 ` Benjamin Herrenschmidt
2010-03-03 5:40 ` James Bottomley
2010-03-03 5:40 ` James Bottomley
2010-03-03 9:36 ` Russell King - ARM Linux
2010-03-03 9:36 ` Russell King - ARM Linux
2010-03-03 10:24 ` James Bottomley
2010-03-03 10:24 ` James Bottomley
2010-03-03 19:41 ` Russell King - ARM Linux
2010-03-03 19:41 ` Russell King - ARM Linux
2010-03-04 2:00 ` Benjamin Herrenschmidt
2010-03-04 2:00 ` Benjamin Herrenschmidt
2010-03-04 8:26 ` James Bottomley
2010-03-04 8:26 ` James Bottomley
2010-03-04 21:25 ` Benjamin Herrenschmidt
2010-03-04 21:25 ` Benjamin Herrenschmidt
2010-03-03 6:35 ` FUJITA Tomonori
2010-03-03 6:35 ` FUJITA Tomonori
2010-03-03 10:43 ` Catalin Marinas
2010-03-03 10:43 ` Catalin Marinas
2010-03-03 10:40 ` Catalin Marinas
2010-03-03 10:40 ` Catalin Marinas
2010-03-03 21:54 ` Pavel Machek
2010-03-03 21:54 ` Pavel Machek
2010-03-04 6:54 ` Wolfgang Mües
2010-03-04 9:31 ` Russell King - ARM Linux
2010-03-06 10:56 ` Wolfgang Mües
2010-03-06 11:05 ` Oliver Neukum
2010-03-06 19:44 ` Russell King - ARM Linux
2010-03-04 13:47 ` Catalin Marinas
2010-03-04 13:35 ` Catalin Marinas
2010-03-04 13:35 ` Catalin Marinas
2010-03-04 13:51 ` Pavel Machek
2010-03-04 13:51 ` Pavel Machek
2010-03-04 14:21 ` James Bottomley
2010-03-04 14:21 ` James Bottomley
2010-03-04 14:27 ` Russell King - ARM Linux
2010-03-04 14:27 ` Russell King - ARM Linux
2010-03-04 15:25 ` Catalin Marinas
2010-03-04 15:25 ` Catalin Marinas
2010-03-04 15:34 ` Russell King - ARM Linux
2010-03-04 15:34 ` Russell King - ARM Linux
2010-03-04 21:31 ` Benjamin Herrenschmidt
2010-03-04 21:31 ` Benjamin Herrenschmidt
2010-03-06 10:47 ` James Bottomley
2010-03-06 10:47 ` James Bottomley
2010-03-06 19:36 ` Russell King - ARM Linux
2010-03-06 19:36 ` Russell King - ARM Linux
2010-03-06 21:07 ` Benjamin Herrenschmidt
2010-03-06 21:07 ` Benjamin Herrenschmidt
2010-03-07 5:54 ` James Bottomley
2010-03-07 5:54 ` James Bottomley
2010-03-08 11:17 ` Catalin Marinas
2010-03-08 11:17 ` Catalin Marinas
2010-03-06 21:03 ` Benjamin Herrenschmidt
2010-03-06 21:03 ` Benjamin Herrenschmidt
2010-03-07 3:37 ` James Bottomley
2010-03-07 3:37 ` James Bottomley
2010-03-08 8:46 ` FUJITA Tomonori
2010-03-08 8:46 ` FUJITA Tomonori
2010-03-09 2:25 ` Benjamin Herrenschmidt
2010-03-09 2:25 ` Benjamin Herrenschmidt
2010-03-04 15:29 ` Catalin Marinas
2010-03-04 15:29 ` Catalin Marinas
2010-03-04 15:41 ` Paul Mundt
2010-03-04 15:41 ` Paul Mundt
2010-03-04 16:30 ` Russell King - ARM Linux
2010-03-04 16:30 ` Russell King - ARM Linux
2010-03-04 17:34 ` Catalin Marinas
2010-03-04 17:34 ` Catalin Marinas
2010-03-04 17:54 ` Russell King - ARM Linux
2010-03-04 17:54 ` Russell King - ARM Linux
2010-03-04 22:27 ` Andreas Mohr
2010-03-04 18:07 ` Catalin Marinas
2010-03-04 18:07 ` Catalin Marinas
2010-03-04 21:37 ` Benjamin Herrenschmidt
2010-03-04 21:37 ` Benjamin Herrenschmidt
2010-03-04 22:11 ` Catalin Marinas
2010-03-04 22:11 ` Catalin Marinas
2010-03-05 4:34 ` Benjamin Herrenschmidt
2010-03-05 4:34 ` Benjamin Herrenschmidt
2010-03-05 9:27 ` Catalin Marinas
2010-03-05 9:27 ` Catalin Marinas
2010-03-05 1:17 ` Paul Mundt
2010-03-05 1:17 ` Paul Mundt
2010-03-05 1:17 ` Paul Mundt
2010-03-05 4:44 ` Benjamin Herrenschmidt
2010-03-05 4:44 ` Benjamin Herrenschmidt
2010-03-05 4:44 ` Benjamin Herrenschmidt
2010-03-10 3:52 ` Paul Mundt
2010-03-10 3:52 ` Paul Mundt
2010-03-10 3:52 ` Paul Mundt
2010-03-11 21:44 ` Benjamin Herrenschmidt
2010-03-11 21:44 ` Benjamin Herrenschmidt
2010-03-11 21:44 ` Benjamin Herrenschmidt
2010-03-04 21:34 ` Benjamin Herrenschmidt
2010-03-04 21:34 ` Benjamin Herrenschmidt
2010-03-04 21:28 ` Benjamin Herrenschmidt
2010-03-04 21:28 ` Benjamin Herrenschmidt
2010-03-04 21:40 ` Russell King - ARM Linux
2010-03-04 21:40 ` Russell King - ARM Linux
2010-03-05 4:31 ` Benjamin Herrenschmidt
2010-03-05 4:31 ` Benjamin Herrenschmidt
2010-03-04 15:35 ` Catalin Marinas
2010-03-04 15:35 ` Catalin Marinas
2010-03-07 8:23 ` Pavel Machek
2010-03-07 8:23 ` Pavel Machek
2010-03-08 10:57 ` Catalin Marinas
2010-03-08 10:57 ` Catalin Marinas
2010-03-02 23:26 ` Benjamin Herrenschmidt
2010-03-02 23:26 ` Benjamin Herrenschmidt
2010-03-01 10:42 ` Catalin Marinas
2010-03-01 10:42 ` Catalin Marinas
2010-03-03 20:24 ` Jamie Lokier
2010-03-03 20:24 ` Jamie Lokier
2010-02-26 21:40 ` Benjamin Herrenschmidt
2010-02-26 21:40 ` Benjamin Herrenschmidt
2010-02-26 21:49 ` Russell King - ARM Linux
2010-02-26 21:49 ` Russell King - ARM Linux
2010-02-28 0:24 ` Benjamin Herrenschmidt
2010-02-28 0:24 ` Benjamin Herrenschmidt
2010-02-28 19:17 ` Pavel Machek
2010-02-28 19:17 ` Pavel Machek
2010-03-01 11:10 ` Catalin Marinas
2010-03-01 11:10 ` Catalin Marinas
2010-03-02 4:11 ` Benjamin Herrenschmidt
2010-03-02 4:11 ` Benjamin Herrenschmidt
2010-02-24 2:39 ` Benjamin Herrenschmidt
2010-02-24 2:39 ` Benjamin Herrenschmidt
2010-02-26 16:44 ` Catalin Marinas
2010-02-26 16:44 ` Catalin Marinas
2010-02-26 21:49 ` Benjamin Herrenschmidt
2010-02-26 21:49 ` Benjamin Herrenschmidt
2010-02-26 22:03 ` Russell King - ARM Linux
2010-02-26 22:03 ` Russell King - ARM Linux
2010-02-28 0:29 ` Benjamin Herrenschmidt
2010-02-28 0:29 ` Benjamin Herrenschmidt
2010-02-28 23:20 ` Catalin Marinas
2010-02-28 23:20 ` Catalin Marinas
2010-02-28 23:17 ` Catalin Marinas
2010-02-28 23:17 ` Catalin Marinas
2010-02-17 15:27 ` Catalin Marinas
2010-02-17 15:27 ` Catalin Marinas
2010-02-17 15:39 ` Catalin Marinas
2010-02-17 15:39 ` Catalin Marinas
2010-02-17 15:40 ` Catalin Marinas
2010-02-17 15:40 ` Catalin Marinas
2010-02-17 15:40 ` Catalin Marinas
2010-02-17 15:40 ` Catalin Marinas
2010-02-17 16:19 ` Catalin Marinas
2010-02-17 16:19 ` Catalin Marinas
2010-02-17 16:19 ` Catalin Marinas
2010-02-17 16:19 ` Re: " Catalin Marinas
2010-02-16 8:44 ` Russell King - ARM Linux
2010-02-16 8:44 ` Russell King - ARM Linux
2010-02-16 8:51 ` Gadiyar, Anand
2010-02-16 8:51 ` Gadiyar, Anand
2010-02-20 7:21 ` Pete Zaitcev
2010-02-20 7:21 ` Pete Zaitcev
-- strict thread matches above, loose matches on Subject: below --
2010-02-03 23:56 George Spelvin
2010-02-04 4:39 ` Paul Mundt
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