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From: jacmet@sunsite.dk (Peter Korsgaard)
To: linux-arm-kernel@lists.infradead.org
Subject: AT91: Fix power-saving in idle-mode on 926T processors
Date: Mon, 10 Jan 2011 16:43:07 +0100	[thread overview]
Message-ID: <87fwt069ys.fsf@macbook.be.48ers.dk> (raw)
In-Reply-To: <1294673540l.26200l.0l@i-dmzi_al.realan.de> (Anders Larsen's message of "Mon, 10 Jan 2011 16:32:20 +0100")

>>>>> "Anders" == Anders Larsen <al@alarsen.net> writes:

Hi,

 >> Is there a known interaction with this and the JTAG controller?

 Anders> indeed there is - disabling the processor clock blocks JTAG debugging.

Ok - And apparently it completely blocks the JTAG controller, so you
cannot even put it in bypass mode and access other devices on the same
JTAG chain.

 >> I haven't had time to look closer into it yet, but with this applied
 >> I can no longer access an Altera FPGA on a chain shared with a 9G45
 >> through Quartus.

 Anders> If you boot with the kernel parameter "nohlt", arch_idle() is
 Anders> not called, and JTAG should work again (but of course power
 Anders> consumption will be substantially higher).

 Anders> This was noted by Uwe Kleine-K?nig in
 Anders> https://lkml.org/lkml/2010/5/5/342

Thanks.

-- 
Bye, Peter Korsgaard

  reply	other threads:[~2011-01-10 15:43 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-10-07 19:44 AT91: Fix power-saving in idle-mode on 926T processors Anders Larsen
2010-10-07 19:44 ` Anders Larsen
2010-10-08 12:29 ` Jean-Christophe PLAGNIOL-VILLARD
2010-10-08 12:29   ` Jean-Christophe PLAGNIOL-VILLARD
2010-10-08 13:51   ` Nicolas Ferre
2010-10-08 13:51     ` Nicolas Ferre
2011-01-10 15:05 ` Peter Korsgaard
2011-01-10 15:32   ` Anders Larsen
2011-01-10 15:43     ` Peter Korsgaard [this message]
2011-01-10 19:23       ` Uwe Kleine-König

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