Re: [media] dib0700: get rid of on-stack dma buffers

From: Patrick Boettcher
Date: Mon Apr 04 2011 - 04:02:00 EST


Hi Florian,

On Sun, 3 Apr 2011, Florian Mickler wrote:

Hi,

since I got no reaction[1] on the vp702x driver, I proceed with the
dib0700.

There are multiple drivers in drivers/media/dvb/dvb-usb/ which use
usb_control_msg to perform dma to stack-allocated buffers. This is a bad idea
because of cache-coherency issues and on some platforms the stack is mapped
virtually and also lib/dma-debug.c warn's about it at runtime.

Patches to ec168, ce6230, au6610 and lmedm04 were already tested and reviewed
and submitted for inclusion [2]. Patches to a800, vp7045, friio, dw2102, m920x
and opera1 are still waiting for for review and testing [3].

This patch to dib0700 is a fix for a warning seen and reported by Zdenek
Kabalec in Bug #15977 [4].

Florian Mickler (2):
[media] dib0700: get rid of on-stack dma buffers

For this one we implemented an alternative. See here:

http://git.linuxtv.org/pb/media_tree.git?a=commit;h=16b54de2d8b46e48c5c8bdf9b350eac04e8f6b46

which I pushed, but obviously forgot to send the pull-request.

This is done now.

For the second patch I will incorperate it as soon as I find the time.

best regards,
--

Patrick
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