Re: Out-of-tree modules [was: Linux Security *Module* Framework]

From: Jan Engelhardt
Date: Mon Oct 29 2007 - 21:19:23 EST



On Oct 29 2007 20:46, Lee Revell wrote:
>On 10/29/07, Jan Engelhardt <jengelh@xxxxxxxxxxxxxxx> wrote:
>> quad_dsp - http://jengelh.hopto.org/p/quad_dsp/
>>
>> Provides a /dev/dsp style node for legacy applications that support
>> neither ALSA nor the AOSS wrapper nor more-than-2-channel sound.
>>
>
>(I think that should read "AND more than 2 channel sound")

It is for programs that only give out 2 channels of audio data.
Qdsp_dpl2 is a node that applies the DPL2 matrix on these two channels,
yielding the rear 2 channels, giving some sort of surround effect.

>Couldn't ALSA's OSS emulation be extended to support more than 2
>channels per device node?

I figured that exceeded my skills at that time.

>> thkd - ftp://ftp5.gwdg.de/pub/linux/misc/suser-jengelh/kernel/linux-2.6.23.1-ccj58/thkd.diff
>>
>> Workaround for Toshiba MK2003GAH hard-drive head auto-unloading after
>> 5-15 seconds. (Ref: http://lkml.org/lkml/2006/11/15/100 )
>
>It looks like this could be trivially fixed in a mergeable way. That
>LKML thread petered out before the problem was seriously analyzed.
>
>Did you try the -Z flag of hdparm?

IIRC, yes, been through all sorts of hdparm options. -Z did not help
at all, and -B only prolonged the delay from 5 to around 15 seconds.
I contacted Tosh Corp (before posting on lkml) and while they know of
the 'issue', I did not get a satisfactory answer (namely how to FIX
it), so I thought why spend time slapping if there's a workaround...

Causing a minimal head seek every now and then (4096 bytes per 3
seconds is a somewhat small block size with a not-too-low interval)
is a working workaround for now. The module code is not top notch,
but I doubt I'll ever have more than one 1.8" MK2003GAH disk in the
same laptop.
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