From: Oliver Neukum <oliver@neukum.org>
To: Florian Mickler <florian@mickler.org>
Cc: mchehab@infradead.org, linux-media@vger.kernel.org,
linux-kernel@vger.kernel.org,
"Greg Kroah-Hartman" <greg@kroah.com>,
"Rafael J. Wysocki" <rjw@sisk.pl>,
Maciej Rutecki <maciej.rutecki@gmail.com>
Subject: Re: [PATCH] [media] dib0700: get rid of on-stack dma buffers
Date: Sun, 6 Mar 2011 17:44:15 +0100 [thread overview]
Message-ID: <201103061744.15946.oliver@neukum.org> (raw)
In-Reply-To: <20110306164521.2a88a155@schatten.dmk.lab>
Am Sonntag, 6. März 2011, 16:45:21 schrieb Florian Mickler:
> Hm.. allocating the buffer
> in the probe routine and deallocating it in the usb_driver disconnect
> callback should work?
Yes.
> How come that it must be a seperate kmalloc buffer? Is it some aligning
> that kmalloc garantees?
On some CPUs DMA affects on main CPU, not the CPU caches. You
need to synchronize the cache before you start DMA and must not touch
the buffer until DMA is finished. This applies with a certain granularity
that kmalloc respects. The ugly details are in Documentation.
Regards
Oliver
next prev parent reply other threads:[~2011-03-06 16:43 UTC|newest]
Thread overview: 36+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-03-06 11:16 [PATCH] [media] dib0700: get rid of on-stack dma buffers Florian Mickler
2011-03-06 12:06 ` Oliver Neukum
2011-03-06 14:38 ` Florian Mickler
2011-03-06 14:45 ` [PATCH 1/3 v2] " Florian Mickler
2011-03-06 14:45 ` [PATCH 2/3] [media] dib0700: remove unused variable Florian Mickler
2011-03-06 14:45 ` [PATCH 3/3] [media] dib0700: don't ignore errors in driver probe Florian Mickler
2011-03-06 15:06 ` [PATCH] [media] dib0700: get rid of on-stack dma buffers Oliver Neukum
2011-03-06 15:45 ` Florian Mickler
2011-03-06 16:44 ` Oliver Neukum [this message]
2011-03-06 17:47 ` [PATCH 1/2 v3] " Florian Mickler
2011-03-06 17:47 ` [PATCH 2/2] [media] dib0700: remove unused variable Florian Mickler
2011-03-06 17:57 ` [PATCH 1/2 v3] [media] dib0700: get rid of on-stack dma buffers Florian Mickler
2011-03-15 8:36 ` Florian Mickler
2011-03-15 8:43 ` [PATCH 01/16] " Florian Mickler
2011-03-15 8:43 ` [PATCH 02/16] [media] dib0700: remove unused variable Florian Mickler
2011-03-15 8:43 ` [PATCH 03/16] [media] a800: get rid of on-stack dma buffers Florian Mickler
2011-03-15 8:43 ` [PATCH 04/16] [media] vp7045: " Florian Mickler
2011-03-15 8:43 ` [PATCH 05/16] [media] ec168: get rid of on stack " Florian Mickler
2011-03-18 16:36 ` Antti Palosaari
2011-03-18 21:33 ` Florian Mickler
2011-03-15 8:43 ` [PATCH 06/16] [media] ce6230: get rid of on-stack dma buffer Florian Mickler
2011-03-18 16:36 ` Antti Palosaari
2011-03-18 21:28 ` Florian Mickler
2011-03-15 8:43 ` [PATCH 07/16] [media] friio: get rid of on-stack dma buffers Florian Mickler
2011-03-15 8:43 ` [PATCH 11/16] [media] lmedm04: correct indentation Florian Mickler
2011-03-15 8:43 ` [PATCH 12/16] [media] lmedm04: get rid of on-stack dma buffers Florian Mickler
2011-03-15 20:54 ` Malcolm Priestley
2011-03-15 21:46 ` Florian Mickler
2011-03-15 12:02 ` [PATCH 01/16] [media] dib0700: " Mauro Carvalho Chehab
2011-03-15 21:14 ` Florian Mickler
[not found] ` <1300178655-24832-9-git-send-email-florian@mickler.org>
2011-03-18 16:34 ` [PATCH 09/16] [media] au6610: get rid of on-stack dma buffer Antti Palosaari
2011-03-18 21:27 ` Florian Mickler
2011-03-18 21:40 ` Antti Palosaari
2011-03-15 11:37 ` [PATCH 1/2 v3] [media] dib0700: get rid of on-stack dma buffers Mauro Carvalho Chehab
2011-03-06 13:49 ` [PATCH] " Jack Stone
2011-03-06 14:00 ` Florian Mickler
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