6.0-CURRENT SNAP004 hangs on amr (patch)

M. Warner Losh imp at bsdimp.com
Sat Sep 10 20:17:19 PDT 2005

In message: <43236E04.4020208 at samsco.org>
            Scott Long <scottl at samsco.org> writes:
: Thanks for the invesitgative work.  I strenously objected to this change
: when it went in, and this kind of problem is precisely the reason why.
: Turning off device power on the PCI bus willy-nilly is such an 
: incredibly bad idea, even if the hope with it is to get a few extra 
: minutes of battery life on a laptop.

It is *NOT* an incredibly bad idea.  It is suggested by the standards,
and is done by other OSes, including Windows.  I know you don't like
it, but it is very beneficial in many circumstances.  It helps with
heat issues as well as power consumption.

: I worked around this problem with the AAC devices, but I don't know if
: the AMR devices can be worked around the same way.  I've asked Warner in
: private to back out the change.  If he refuses, then I'm afraid that 
: you'll need to remember an undocumented workaround, or find another OS.

I've said before that the right fix is to fix the device drivers that
have knowledge of these split devices.  I still stand by that

So far only two drivers have been affected (amr and aac).  I'm
disinclined to change it because of those two devices.

However, I'll start thinking about this in detail and reconsider it
after some thought.  There may be a better workaround.


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